kth.sePublications
Change search
Refine search result
1 - 46 of 46
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Alexakis, Alexandros Efraim
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Ayyachi, Thayanithi
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Mousa, Maryam
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Olsen, Peter
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Biocomposites.
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    2-Methoxy-4-Vinylphenol as a Biobased Monomer Precursor for Thermoplastics and Thermoset Polymers2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 9, article id 2168Article in journal (Refereed)
    Abstract [en]

    To address the increasing demand for biobased materials, lignin-derived ferulic acid (FA) is a promising candidate. In this study, an FA-derived styrene-like monomer, referred to as 2-methoxy-4-vinylphenol (MVP), was used as the platform to prepare functional monomers for radical polymerizations. Hydrophobic biobased monomers derived from MVP were polymerized via solution and emulsion polymerization resulting in homo- and copolymers with a wide range of thermal properties, thus showcasing their potential in thermoplastic applications. Moreover, divinylbenzene (DVB)-like monomers were prepared from MVP by varying the aliphatic chain length between the MVP units. These biobased monomers were thermally crosslinked with thiol-bearing reagents to produce thermosets with different crosslinking densities in order to demonstrate their thermosetting applications. The results of this study expand the scope of MVP-derived monomers that can be used in free-radical polymerizations toward the preparation of new biobased and functional materials from lignin.

  • 2.
    Alipour, Nazanin
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Vinneras, Bjorn
    SLU Swedish Univ Agr Sci, Dept Energy & Technol, POB 7032, SE-75007 Uppsala, Sweden..
    Gouanve, Fabrice
    Univ Lyon 1, Univ Lyon, Ingn Mat Polymeres, CNRS,UMR 5223, 15 Bd Andre Latarjet, F-69622 Villeurbanne, France..
    Espuche, Eliane
    Univ Lyon 1, Univ Lyon, Ingn Mat Polymeres, CNRS,UMR 5223, 15 Bd Andre Latarjet, F-69622 Villeurbanne, France..
    Hedenqvist, Mikael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    A Protein-Based Material from a New Approach Using Whole Defatted Larvae, and Its Interaction with Moisture2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 2, article id 287Article in journal (Refereed)
    Abstract [en]

    A protein-based material created from a new approach using whole defatted larvae of the Black Soldier fly is presented. The larvae turn organic waste into their own biomass with high content of protein and lipids, which can be used as animal feed or for material production. After removing the larva lipid and adding a plasticizer, the ground material was compression molded into plates/films. The lipid, rich in saturated fatty acids, can be used in applications such as lubricants. The amino acids present in the greatest amounts were the essential amino acids aspartic acid/asparagine and glutamic acid/glutamine. Infrared spectroscopy revealed that the protein material had a high amount of strongly hydrogen-bonded beta-sheets, indicative of a highly aggregated protein. To assess the moisture-protein material interactions, the moisture uptake was investigated. The moisture uptake followed a BET type III moisture sorption isotherm, which could be fitted to the Guggenheim, Anderson and de Boer (GAB) equation. GAB, in combination with cluster size analysis, revealed that the water clustered in the material already at a low moisture content and the cluster increased in size with increasing relative humidity. The clustering also led to a peak in moisture diffusivity at an intermediate moisture uptake.

  • 3.
    Almesmari, Abdulla
    et al.
    Advanced Digital & Additive Manufacturing Center, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates, P.O. Box 127788; Department of Mechanical Engineering, School of Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates, P.O. Box 127788.
    Baghous, Nareg
    Advanced Digital & Additive Manufacturing Center, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates, P.O. Box 127788; Department of Mechanical Engineering, School of Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates, P.O. Box 127788.
    Ejeh, Chukwugozie J.
    Advanced Digital & Additive Manufacturing Center, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates, P.O. Box 127788; Department of Mechanical Engineering, School of Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates, P.O. Box 127788.
    Barsoum, Imad
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. Advanced Digital & Additive Manufacturing Center, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Department of Mechanical Engineering, School of Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
    Abu Al-Rub, Rashid K.
    Advanced Digital & Additive Manufacturing Center, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates, P.O. Box 127788; Department of Mechanical Engineering, School of Engineering, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates, P.O. Box 127788.
    Review of Additively Manufactured Polymeric Metamaterials: Design, Fabrication, Testing and Modeling2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 19, article id 3858Article, review/survey (Refereed)
    Abstract [en]

    Metamaterials are architected cellular materials, also known as lattice materials, that are inspired by nature or human engineering intuition, and provide multifunctional attributes that cannot be achieved by conventional polymeric materials and composites. There has been an increasing interest in the design, fabrication, and testing of polymeric metamaterials due to the recent advances in digital design methods, additive manufacturing techniques, and machine learning algorithms. To this end, the present review assembles a collection of recent research on the design, fabrication and testing of polymeric metamaterials, and it can act as a reference for future engineering applications as it categorizes the mechanical properties of existing polymeric metamaterials from literature. The research within this study reveals there is a need to develop more expedient and straightforward methods for designing metamaterials, similar to the implicitly created TPMS lattices. Additionally, more research on polymeric metamaterials under more complex loading scenarios is required to better understand their behavior. Using the right machine learning algorithms in the additive manufacturing process of metamaterials can alleviate many of the current difficulties, enabling more precise and effective production with product quality.

  • 4.
    Ashour, Radwa M.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering. Nuclear Materials Authority, P.O. Box 530, ElMaadi, Cairo 11381, Egypt.
    Abdel-Magied, Ahmed Fawzy
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Resource recovery. Nuclear Materials Authority, P.O. Box 530, ElMaadi, Cairo 11381, Egypt.
    Wu, Qiong
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Olsson, Richard
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    Forsberg, Kerstin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Resource recovery.
    Green Synthesis of Metal-Organic Framework Bacterial Cellulose Nanocomposites for Separation Applications2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 5, article id 1104Article in journal (Refereed)
    Abstract [en]

    Metal organic frameworks (MOFs) are porous crystalline materials that can be designed to act as selective adsorbents. Due to their high porosity they can possess very high adsorption capacities. However, overcoming the brittleness of these crystalline materials is a challenge for many industrial applications. In order to make use of MOFs for large-scale liquid phase separation processes they can be immobilized on solid supports. For this purpose, nanocellulose can be considered as a promising supporting material due to its high flexibility and biocompatibility. In this study a novel flexible nanocellulose MOF composite material was synthesised in aqueous media by a novel and straightforward in situ one-pot green method. The material consisted of MOF particles of the type MIL-100(Fe) (from Material Institute de Lavoisier, containing Fe(III) 1,3,5-benzenetricarboxylate) immobilized onto bacterial cellulose (BC) nanofibers. The novel nanocomposite material was applied to efficiently separate arsenic and Rhodamine B from aqueous solution, achieving adsorption capacities of 4.81, and 2.77 mg g‒1, respectively. The adsorption process could be well modelled by the nonlinear pseudo-second-order fitting.

  • 5.
    Avalos, Arturo Salazar
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Odelius, Karin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Superiorly Plasticized PVC/PBSA Blends through Crotonic and Acrylic Acid Functionalization of PVC2017In: Polymers, E-ISSN 2073-4360, Vol. 9, no 3, article id 84Article in journal (Refereed)
    Abstract [en]

    Superior plasticization efficiency was achieved by a grafting from functionalization of the PVC backbone. This was deduced to a synergistic effect of internal plasticization and improved intermolecular interactions between PVC and an oligomeric poly(butylene succinate-co-adipate) ( PBSA) plasticizer. A mild grafting process for functionalization of the PVC chain by crotonic acid ( CA) or acrylic acid ( AA) was used. The formation of PVC-g-CA and PVC-g-AA was confirmed by FTIR and H-1 NMR. Grafting with the seemingly similar monomers, CA and AA, resulted in different macromolecular structures. AA is easily homopolymerized and long hydrophilic poly( acrylic acid) grafts are formed resulting in branched materials. Crotonic acid does not easily homopolymerize; instead, single crotonic acid units are located along the PVC chain, leading to basically linear PVC chains with pendant crotonic acid groups. The elongation of PVC-g-CA and PVC-g-AA in comparison to pure PVC were greatly increased from 6% to 128% and 167%, respectively, by the grafting reactions. Blending 20% ( w/w) PBSA with PVC, PVC-AA or PVC-CA further increased the elongation at break to 150%, 240% and 320%, respectively, clearly showing a significant synergistic effect in the blends with functionalized PVC. This is a clearly promising milestone towards environmentally friendly flexible PVC materials.

  • 6.
    Babu, Karthik
    et al.
    Ctr Polymer Composites & Nat Fiber Res, Chennai 625005, Tamil Nadu, India..
    Rendén, Gabriella
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    Mensah, Rhoda Afriyie
    Nanjing Univ Sci & Technol, Sch Mech Engn, Nanjing 210094, Peoples R China..
    Kim, Nam Kyeun
    Univ Auckland, Ctr Adv Composite Mat, Dept Mech Engn, Auckland 1142, New Zealand..
    Jiang, Lin
    Nanjing Univ Sci & Technol, Sch Mech Engn, Nanjing 210094, Peoples R China..
    Xu, Qiang
    Nanjing Univ Sci & Technol, Sch Mech Engn, Nanjing 210094, Peoples R China..
    Restas, Agoston
    Natl Univ Publ Serv, Dept Fire Protect & Rescue Control, H-1011 Budapest, Hungary..
    Neisiany, Rasoul Esmaeely
    Hakim Sabzevari Univ, Fac Engn, Dept Mat & Polymer Engn, Sabzevar 9617976487, Iran..
    Hedenqvist, Mikael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    Forsth, Michael
    Luleå Univ Technol, Dept Civil Environm & Nat Resources Engn, Struct & Fire Engn Div, S-97187 Luleå, Sweden..
    Bystrom, Alexandra
    Luleå Univ Technol, Dept Civil Environm & Nat Resources Engn, Struct & Fire Engn Div, S-97187 Luleå, Sweden..
    Das, Oisik
    Luleå Univ Technol, Dept Engn Sci & Math, S-97187 Luleå, Sweden..
    A Review on the Flammability Properties of Carbon-Based Polymeric Composites: State-of-the-Art and Future Trends2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 7, p. 1518-Article, review/survey (Refereed)
    Abstract [en]

    Carbon based fillers have attracted a great deal of interest in polymer composites because of their ability to beneficially alter properties at low filler concentration, good interfacial bonding with polymer, availability in different forms, etc. The property alteration of polymer composites makes them versatile for applications in various fields, such as constructions, microelectronics, biomedical, and so on. Devastations due to building fire stress the importance of flame-retardant polymer composites, since they are directly related to human life conservation and safety. Thus, in this review, the significance of carbon-based flame-retardants for polymers is introduced. The effects of a wide variety of carbon-based material addition (such as fullerene, CNTs, graphene, graphite, and so on) on reaction-to-fire of the polymer composites are reviewed and the focus is dedicated to biochar-based reinforcements for use in flame retardant polymer composites. Additionally, the most widely used flammability measuring techniques for polymeric composites are presented. Finally, the key factors and different methods that are used for property enhancement are concluded and the scope for future work is discussed.

  • 7.
    Badria, Adel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Click Chemistry: A Promising Tool for Building Hierarchical Structures2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 19, article id 4077Article, review/survey (Refereed)
    Abstract [en]

    The hierarchical structures are utilized at different levels in nature. Moreover, a wide spectrum of nature’s properties (e.g., mechanical, physical and biological properties) has been attributed to this hierarchy. Different reviews have been published to cover the use of click chemistry in building hierarchical structures. However, each one of those reviews focused on a narrow area on this topic, i.e., specific chemical reaction, such as in thiol-ene chemistry, or a specific molecule or compound such as polyhedral oligomeric silsesquioxane, or a certain range of hierarchical structures between the nano to micro range, e.g., nanocrystals. In this review, a frame to connect the dots between the different published works has been demonstrated. This article will not attempt to give an exhaustive review of all the published work in the field, instead the potential of click chemistry to build hierarchical structures of different levels using building blocks of different length scales has been shown through two main approaches. The first is a one-step direct formation of 3D micro/macrometer dimensions structures from Pico dimensions structures (molecules, monomers, etc.). The second approach includes several steps Pico ➔ 0D nano ➔ 1D nano ➔ 2D nano ➔ 3D nano/micro/macro dimensions structures. Another purpose of this review article is to connect between (a) the atomic theory, which covers the atoms and molecules in the picometer dimensions (picoscopic chemistry set); (b) “nano-periodic system” model, which covers different nanobuilding blocks in the nanometers range such as nanoparticles, dendrimers, buckyball, etc. which was developed by Tomalia; and (c) the micro/macrometer dimensions level.

  • 8.
    Benyahia Erdal, Nejla
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Lando, Gabriela Albara
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. Univ Fed Rio Grande Sul UFRGS, Inst Chem, Dept Phys Chem, Av Bento Goncalves 9500, BR-91501970 Porto Alegre, RS, Brazil..
    Yadav, Anilkumar
    Indian Inst Technol Delhi, Dept Text & Fibre Engn, New Delhi 110016, India..
    Srivastava, Rajiv K.
    Indian Inst Technol Delhi, Dept Text & Fibre Engn, New Delhi 110016, India..
    Hakkarainen, Minna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Hydrolytic Degradation of Porous Crosslinked Poly(epsilon-Caprolactone) Synthesized by High Internal Phase Emulsion Templating2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 8, article id 1849Article in journal (Refereed)
    Abstract [en]

    Porous poly(epsilon-caprolactone) (PCL) scaffolds were fabricated using the high internal polymerization emulsion (HIPE) technique. Bis(epsilon-caprolactone-4-yl) (BCY) was utilized as crosslinker. The crosslinking density and the volume fraction of the dispersed phase were varied in order to study the potential effect of these parameters on the hydrolytic degradation at 37 degrees C and 60 degrees C. After different hydrolysis times the remaining solid samples were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), while the degradation products in the aqueous aging solutions were analyzed by laser desorption ionization-mass spectrometry (LDI-MS). The effect of temperature on the degradation process and release of degradation products was, as expected, significant. The temperature effect was also shown by FTIR analysis that displayed a pronounced increase in the intensity of the hydroxyl-group absorption band after 70 days of hydrolysis at 60 degrees C indicating significant cleavage of the polymer chains. LDI-MS analysis proved the release of oligomers ranging from dimers to hexamers. The product patterns were similar, but the relativem/zsignal intensities increased with increasing time, temperature and crosslinking density, indicating larger amounts of released products. The latter is probably due to the decreasing degree of crystallinity as a function of amount of crosslinker. The porous structure and morphology of the scaffolds were lost during the aging. The higher the crosslinking density, the longer the scaffolds retained their original porous structure and morphology.

  • 9.
    Capezza, Antonio Jose
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    Robert, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Lundman, Malin
    Essity Hyg & Hlth AB, SE-40503 Gothenburg, Sweden..
    Newson, William R.
    SLU Swedish Univ Agr Sci, Dept Plant Breeding, Box 101, SE-23053 Alnarp, Sweden..
    Johansson, Eva
    SLU Swedish Univ Agr Sci, Dept Plant Breeding, Box 101, SE-23053 Alnarp, Sweden..
    Hedenqvist, Mikael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Olsson, Richard
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    Extrusion of Porous Protein-Based Polymers and Their Liquid Absorption Characteristics2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 2, article id 459Article in journal (Refereed)
    Abstract [en]

    The production of porous wheat gluten (WG) absorbent materials by means of extrusion processing is presented for the future development of sustainable superabsorbent polymers (SAPs). Different temperatures, formulations, and WG compositions were used to determine a useful protocol that provides the best combination of porosity and water swelling properties. The most optimal formulation was based on 50 wt.% WG in water that was processed at 80 degrees C as a mixture, which provided a porous core structure with a denser outer shell. As a green foaming agent, food-grade sodium bicarbonate was added during the processing, which allowed the formation of a more open porous material. This extruded WG material was able to swell 280% in water and, due to the open-cell structure, 28% with non-polar limonene. The results are paving the way towards production of porous bio macromolecular structures with high polar/non-polar liquid uptake, using extrusion as a solvent free and energy efficient production technique without toxic reagents.

  • 10.
    Coja, Michael
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Using Waveguides to Model the Dynamic Stiffness of Pre-Compressed Natural Rubber Vibration Isolators2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 11, article id 1703Article in journal (Refereed)
    Abstract [en]

    A waveguide model for a pre-compressed cylindrical natural rubber vibration isolator is developed within a wide frequency range-20 to 2000 Hz-and for a wide pre-compression domain-from vanishing to the maximum in service, that is 20%. The problems of simultaneously modeling the pre-compression and frequency dependence are solved by applying a transformation of the pre-compressed isolator into a globally equivalent linearized, homogeneous, and isotropic form, thereby reducing the original, mathematically arduous, and complex problem into a vastly simpler assignment while using a straightforward waveguide approach to satisfy the boundary conditions by mode-matching. A fractional standard linear solid is applied as the visco-elastic natural rubber model while using a Mittag-Leffler function as the stress relaxation function. The dynamic stiffness is found to depend strongly on the frequency and pre-compression. The former is resulting in resonance phenomena such as peaks and troughs, while the latter exhibits a low-frequency magnitude stiffness increase in addition to peak and trough shifts with increased pre-compressions. Good agreement with nonlinear finite element results is obtained for the considered frequency and pre-compression range in contrast to the results of standard waveguide approaches.

  • 11.
    De Mori, Arianna
    et al.
    School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK..
    Peña Fernández, Marta
    Zeiss Global Centre, School of Mechanical and Design Engineering, University of Portsmouth, Portsmouth, PO1 3DJ, UK.
    Blunn, Gordon
    School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK..
    Tozzi, Gianluca
    Zeiss Global Centre, School of Engineering, University of Portsmouth, Portsmouth PO1 3DJ, UK..
    Roldo, Marta
    School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth PO1 2DT, UK..
    3D Printing and Electrospinning of Composite Hydrogels for Cartilage and Bone Tissue Engineering.2018In: Polymers, E-ISSN 2073-4360, Vol. 10, no 3, article id E285Article in journal (Refereed)
    Abstract [en]

    Injuries of bone and cartilage constitute important health issues costing the National Health Service billions of pounds annually, in the UK only. Moreover, these damages can become cause of disability and loss of function for the patients with associated social costs and diminished quality of life. The biomechanical properties of these two tissues are massively different from each other and they are not uniform within the same tissue due to the specific anatomic location and function. In this perspective, tissue engineering (TE) has emerged as a promising approach to address the complexities associated with bone and cartilage regeneration. Tissue engineering aims at developing temporary three-dimensional multicomponent constructs to promote the natural healing process. Biomaterials, such as hydrogels, are currently extensively studied for their ability to reproduce both the ideal 3D extracellular environment for tissue growth and to have adequate mechanical properties for load bearing. This review will focus on the use of two manufacturing techniques, namely electrospinning and 3D printing, that present promise in the fabrication of complex composite gels for cartilage and bone tissue engineering applications.

  • 12.
    Finnveden, Maja
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Hendil-Forssell, Peter
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Claudino, Mauro
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Martinelle, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Lipase-Catalyzed Synthesis of Renewable Plant Oil-Based Polyamides.2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 11, article id 1730Article in journal (Refereed)
    Abstract [en]

    Enzyme catalyzed synthesis of renewable polyamides was investigated using Candida antarctica lipase B. A fatty acid-derived AB-type functional monomer, having one amine and one methyl ester functionality, was homopolymerized at 80 and 140 °C. Additionally, the organobase 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) was used as a catalyst. The results from the two catalysts were comparable. However, the amount of lipase added was 1.2 × 103 times lower, showing that the lipase was a more efficient catalyst for this system as compared to TBD. Moreover, the AB-type monomer was copolymerized with 1,12-diaminododecane to synthesize oligoamides of two different lengths.

  • 13.
    Fuoco, Tiziana
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Chen, Mo
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Sustainable Production Systems.
    Jain, Shubham
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Wang, Xi Vincent
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Sustainable Production Systems.
    Wang, Lihui
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering, Sustainable Production Systems.
    Finne Wistrand, Anna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Hydrogel Polyester Scaffolds via Direct-Ink-Writing of Ad Hoc Designed Photocurable Macromonomer2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 4, article id 711Article in journal (Refereed)
    Abstract [en]

    Synthetic, degradable macromonomers have been developed to serve as ink for 3D printing technologies based on direct-ink-writing. The macromonomers are purposely designed to be cross-linkable under the radical mechanism, to impart hydrophilicity to the final material, and to have rheological properties matching the printer's requirements. The suitable viscosity enables the ink to be printed at room temperature, in absence of organic solvents, and to be cross-linked to manufacture soft 3D scaffolds that show no indirect cytotoxicity and have a hydration capacity of up to 100% their mass and a compressive modulus in the range of 0.4-2 MPa.

  • 14.
    Goliszek, Marta
    et al.
    Marie Curie Sklodowska Univ, Fac Chem, Inst Chem Sci, Dept Polymer Chem, M Curie Sklodowska Sq 5, PL-20031 Lublin, Poland.;Marie Curie Sklodowska Univ, Fac Chem, Inst Chem Sci, Analyt Lab, M Curie Sklodowska Sq 5, PL-20031 Lublin, Poland..
    Podkoscielna, Beata
    Marie Curie Sklodowska Univ, Fac Chem, Inst Chem Sci, Dept Polymer Chem, M Curie Sklodowska Sq 5, PL-20031 Lublin, Poland..
    Klepka, Tomasz
    Lublin Univ Technol, Fac Mech Engn, Dept Technol & Polymer Proc, Nadbystrzycka 36, PL-20618 Lublin, Poland..
    Sevastyanova, Olena
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Preparation, Thermal, and Mechanical Characterization of UV-Cured Polymer Biocomposites with Lignin2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 5Article in journal (Refereed)
    Abstract [en]

    The preparation and the thermal and mechanical characteristics of lignin-containing polymer biocomposites were studied. Bisphenol A glycerolate (1 glycerol/phenol) diacrylate (BPA.GDA) was used as the main monomer, and butyl acrylate (BA), 2-ethylhexyl acrylate (EHA) or styrene (St) was used as the reactive diluent. Unmodified lignin (L) or lignin modified with methacryloyl chloride (L-M) was applied as an ecofriendly component. The influences of the lignin, its modification, and of the type of reactive diluent on the properties of the composites were investigated. In the biocomposites with unmodified lignin, the lignin mainly acted as a filler, and it seemed that interactions occurred between the hydroxyl groups of the lignin and the carbonyl groups of the acrylates. When methacrylated lignin was applied, it seemed to take part in the creation of a polymer network. When styrene was added as a reactive diluent, the biocomposites had a more homogeneous structure, and their thermal resistance was higher than those with acrylate monomers. The use of lignin and its methacrylic derivative as a component in polymer composites promotes sustainability in the plastics industry and can have a positive influence on environmental problems related to waste generation.

  • 15. Hoang, A. T.
    et al.
    Pallon, Love
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Liu, Dongming
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Serdyuk, Y. V.
    Gubanski, S. M.
    Gedde, Ulf W.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Charge transport in LDPE nanocomposites part I-experimental approach2016In: Polymers, E-ISSN 2073-4360, Vol. 8, no 3, p. 1-19Article in journal (Refereed)
    Abstract [en]

    This work presents results of bulk conductivity and surface potential decay measurements on low-density polyethylene and its nanocomposites filled with uncoated MgO and Al2O3, with the aim to highlight the effect of the nanofillers on charge transport processes. Material samples at various filler contents, up to 9 wt %, were prepared in the form of thin films. The performed measurements show a significant impact of the nanofillers on reduction of material's direct current (dc) conductivity. The investigations thus focused on the nanocomposites having the lowest dc conductivity. Various mechanisms of charge generation and transport in solids, including space charge limited current, Poole-Frenkel effect and Schottky injection, were utilized for examining the experimental results. The mobilities of charge carriers were deduced from the measured surface potential decay characteristics and were found to be at least two times lower for the nanocomposites. The temperature dependencies of the mobilities were compared for different materials.

  • 16.
    Hsieh, Yves S. Y.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Harris, Philip J.
    University of Auckland.
    Xylans of red and green algae: what is known about their structures and how they are synthesised?2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 2, article id 354Article, book review (Refereed)
    Abstract [en]

    Xylans with a variety of structures have been characterised in green algae, including chlorophytes (Chlorophyta) and charophytes (in the Streptophyta), and red algae (Rhodophyta). Substituted 1,4-β-d-xylans, similar to those in land plants (embryophytes), occur in the cell wall matrix of advanced orders of charophyte green algae. Small proportions of 1,4-β-d-xylans have also been found in the cell walls of some chlorophyte green algae and red algae but have not been well characterised. 1,3-β-d-Xylans occur as triple helices in microfibrils in the cell walls of chlorophyte algae in the order Bryopsidales and of red algae in the order Bangiales. 1,3;1,4-β-d-Xylans occur in the cell wall matrix of red algae in the orders Palmariales and Nemaliales. In the angiosperm Arabidopsis thaliana, the gene IRX10 encodes a xylan 1,4-β-d-xylosyltranferase (xylan synthase), and, when heterologously expressed, this protein catalysed the production of the backbone of 1,4-β-d-xylans. An orthologous gene from the charophyte green alga Klebsormidium flaccidum, when heterologously expressed, produced a similar protein that was also able to catalyse the production of the backbone of 1,4-β-d-xylans. Indeed, it is considered that land plant xylans evolved from xylans in ancestral charophyte green algae. However, nothing is known about the biosynthesis of the different xylans found in chlorophyte green algae and red algae. There is, thus, an urgent need to identify the genes and enzymes involved.

    Download full text (pdf)
    fulltext
  • 17.
    Hussain, Humair
    et al.
    King Abdulaziz Univ, Ctr Nanotechnol, Jeddah 21589, Saudi Arabia.;King Abdulaziz Univ, Fac Sci, Phys Dept, Jeddah 21589, Saudi Arabia..
    Jilani, Asim
    King Abdulaziz Univ, Ctr Nanotechnol, Jeddah 21589, Saudi Arabia..
    Salah, Numan
    King Abdulaziz Univ, Ctr Nanotechnol, Jeddah 21589, Saudi Arabia..
    Alshahrie, Ahmed
    King Abdulaziz Univ, Ctr Nanotechnol, Jeddah 21589, Saudi Arabia.;King Abdulaziz Univ, Fac Sci, Phys Dept, Jeddah 21589, Saudi Arabia..
    MemiC, Adnan
    King Abdulaziz Univ, Ctr Nanotechnol, Jeddah 21589, Saudi Arabia..
    Ansari, Mohammad Omaish
    King Abdulaziz Univ, Ctr Nanotechnol, Jeddah 21589, Saudi Arabia..
    Dutta, Joydeep
    KTH, School of Engineering Sciences (SCI), Applied Physics, Materials and Nanophysics. King Abdulaziz Univ, Ctr Nanotechnol, Jeddah 21589, Saudi Arabien..
    Freestanding Activated Carbon Nanocomposite Electrodes for Capacitive Deionization of Water2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 14, article id 2891Article in journal (Refereed)
    Abstract [en]

    Freshwater reserves are being polluted every day due to the industrial revolution. Man-made activities have adverse effects upon the ecosystem. It is thus the hour of need to explore newer technologies to save and purify water for the growing human population. Capacitive deionization (CDI) is being considered as an emerging technique for removal of excess ions to produce potable water including desalination. Herein, cost-effective activated carbon incorporated with carbon nanotubes (CNT) was used as a freestanding electrode. Further, the desalination efficiency of the designed electrodes was tuned by varying binder concentration, i.e., polyvinylidene difluoride (PVDF) in the activated carbon powder and CNT mixture. PVDF concentration of 5, 7.5, 10, and 12.5 wt% was selected to optimize the freestanding electrode formation and further applied for desalination of water. PVDF content affected the surface morphology, specific surface area, and functional groups of the freestanding electrodes. Moreover, the electrical conductivity and specific surface area changed with PVDF concentration, which ultimately affected the desalination capacity using the freestanding electrodes. This study paves the way to produce cost effective carbon-based freestanding electrodes for capacitive deionization and other applications including battery electrodes.

  • 18.
    Hussein, Mohamed Ahmed Mohamady
    et al.
    Univ Hosp RWTH Aachen, Dermatol Clin, D-52074 Aachen, Germany.;Natl Res Ctr, Med Res Div, Dept Pharmacol, Cairo 12622, Egypt..
    Su, Sena
    Marmara Univ, Ctr Nanotechnol & Biomat Applicat & Res NBUAM, TR-34722 Istanbul, Turkey..
    Ulag, Songul
    Marmara Univ, Ctr Nanotechnol & Biomat Applicat & Res NBUAM, TR-34722 Istanbul, Turkey..
    Wozniak, Agata
    Univ Gdansk, Intercollegiate Fac Biotechnol, Dept Biotechnol, Lab Mol Diagnost, PL-80307 Gdansk, Poland..
    Grinholc, Mariusz
    Univ Gdansk, Intercollegiate Fac Biotechnol, Dept Biotechnol, Lab Mol Diagnost, PL-80307 Gdansk, Poland..
    Erdemir, Goekce
    Istanbul Univ, Aziz Sancar Inst Expt Med, Dept Mol Med, TR-34390 Istanbul, Turkey.;Istinye Univ, Mol Canc Res Ctr ISUMKAM, TR-34010 Istanbul, Turkey..
    Erdem Kuruca, Serap
    Istanbul Univ, Fac Med, Dept Physiol, TR-34390 Istanbul, Turkey..
    Gunduz, Oguzhan
    Marmara Univ, Ctr Nanotechnol & Biomat Applicat & Res NBUAM, TR-34722 Istanbul, Turkey.;Marmara Univ, Fac Technol, Dept Met & Mat Engn, TR-34722 Istanbul, Turkey..
    Muhammed, Mamoun
    KTH.
    El-Sherbiny, Ibrahim M.
    Ctr Mat Sci CMS, Zewail City Sci & Technol, Nanomed Lab, Giza 12578, Egypt..
    Megahed, Mosaad
    Univ Hosp RWTH Aachen, Dermatol Clin, D-52074 Aachen, Germany..
    Development and In Vitro Evaluation of Biocompatible PLA-Based Trilayer Nanofibrous Membranes for the Delivery of Nanoceria: A Novel Approach for Diabetic Wound Healing2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 21, article id 3630Article in journal (Refereed)
    Abstract [en]

    The attempts to explore and optimize the efficiency of diabetic wound healing's promotors are still in progress. Incorporation of cerium oxide nanoparticles (nCeO(2)) in appropriate nanofibers (NFs) can prolong and maximize their promoting effect for the healing of diabetic wounds, through their sustained releases, as well as the nanofibers role in mimicking of the extra cellular matrix (ECM). The as-prepared nCeO(2) were analyzed by using UV-Vis spectroscopy, XRD, SEM-EDX, TEM and FTIR, where TEM and SEM images of both aqueous suspension and powder showed spherical/ovoid-shaped particles. Biodegradable trilayer NFs with cytobiocompatibility were developed to sandwich nCeO(2) in PVA NFs as a middle layer where PLA NFs were electrospun as outer bilayer. The nCeO(2)-loaded trilayer NFs were characterized by SEM, XRD, FTIR and DSC. A two-stage release behavior was observed when the nanoceria was released from the trilayer-based nanofibers; an initial burst release took place, and then it was followed by a sustained release pattern. The mouse embryo fibroblasts, i.e., 3T3 cells, were seeded over the nCeO(2)-loaded NFs mats to investigate their cyto-biocompatibility. The presence and sustained release of nCeO(2) efficiently enhance the adhesion, growth and proliferation of the fibroblasts' populations. Moreover, the incorporation of nCeO(2) with a higher amount into the designed trilayer NFs demonstrated a significant improvement in morphological, mechanical, thermal and cyto-biocompatibility properties than lower doses. Overall, the obtained results suggest that designated trilayer nanofibrous membranes would offer a specific approach for the treatment of diabetic wounds through an effective controlled release of nCeO(2).

  • 19.
    Karpov, Sergei, V
    et al.
    Russian Acad Sci, Dept Polymers & Composite Mat, Fed Res Ctr Problems Chem Phys & Med Chem, Chernogolovka 142432, Russia..
    Iakunkov, Artem
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Akkuratov, Alexander, V
    Russian Acad Sci, Dept Polymers & Composite Mat, Fed Res Ctr Problems Chem Phys & Med Chem, Chernogolovka 142432, Russia..
    Petrov, Artem O.
    Russian Acad Sci, Dept Polymers & Composite Mat, Fed Res Ctr Problems Chem Phys & Med Chem, Chernogolovka 142432, Russia..
    Perepelitsina, Eugenia O.
    Russian Acad Sci, Dept Polymers & Composite Mat, Fed Res Ctr Problems Chem Phys & Med Chem, Chernogolovka 142432, Russia..
    Malkov, Georgiy, V
    Russian Acad Sci, Dept Polymers & Composite Mat, Fed Res Ctr Problems Chem Phys & Med Chem, Chernogolovka 142432, Russia..
    Badamshina, Elmira R.
    Russian Acad Sci, Dept Polymers & Composite Mat, Fed Res Ctr Problems Chem Phys & Med Chem, Chernogolovka 142432, Russia..
    One-Pot Synthesis of Hyperbranched Polyurethane-Triazoles with Controlled Structural, Molecular Weight and Hydrodynamic Characteristics2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 21, article id 4514Article in journal (Refereed)
    Abstract [en]

    We report a simple and convenient approach to the one-pot synthesis of hyperbranched polyurethane-triazoles with desirable properties. This method is based on in situ generation of an AB(2) + A(2) + B-4 azide-acetylene monomer mixture of known composition, due to quantitative reactions of urethane formation between isophorone diisocyanate (IPDI), 1,3-diazidopropanol-2 (DAPOL) (in the first stage) and propargyl alcohol (in the second stage). The obtained monomer mixture can be involved in step-growth polymerization by azide-alkyne cycloaddition without additional purification (in the third stage). The properties of the resulting polymers should depend on the composition of the monomer mixture. Therefore, first the model revealing the correlation between the monomer composition and the ratio and reactivity of the IPDI and DAPOL active groups is developed and proven. In addition, the newly developed structural kinetic model considering the substitution effect at polyaddition of the complex mixture of monomers allows the prediction of the degree of branching of the target polymer. Based on our calculations, the hyperbranched polyurethane-triazoles were synthesized under found conditions. All products were characterized by H-1 NMR, FTIR, SEC, DLS, DSC, TGA and viscometry methods. It was shown that the degree of branching, molecular weight, intrinsic viscosity, and hydrodynamic radius of the final hyperbranched polymers can be specified at the first stage of one-pot synthesis. The obtained hyperbranched polyurethane-triazoles showed a degree of branching from 0.21 to 0.44 (calculated DB-0.25 and 0.45, respectively).

  • 20.
    Karpov, Sergei V.
    et al.
    Department of Polymers and Composites, Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry of Russian Academy of Sciences, 1 Academician Semenov Avenue, Chernogolovka, 142432, Russia, 1 Academician Semenov Avenue.
    Iakunkov, Artem
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Chernyaev, Dmitry A.
    Department of Polymers and Composites, Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry of Russian Academy of Sciences, 1 Academician Semenov Avenue, Chernogolovka, 142432, Russia, 1 Academician Semenov Avenue.
    Kurbatov, Vladimir G.
    Department of Polymers and Composites, Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry of Russian Academy of Sciences, 1 Academician Semenov Avenue, Chernogolovka, 142432, Russia, 1 Academician Semenov Avenue.
    Malkov, Georgiy V.
    Department of Polymers and Composites, Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry of Russian Academy of Sciences, 1 Academician Semenov Avenue, Chernogolovka, 142432, Russia, 1 Academician Semenov Avenue.
    Badamshina, Elmira R.
    Department of Polymers and Composites, Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry of Russian Academy of Sciences, 1 Academician Semenov Avenue, Chernogolovka, 142432, Russia, 1 Academician Semenov Avenue.
    A Theoretical Investigation of the Polyaddition of an AB2+A2+B4 Monomer Mixture2024In: Polymers, E-ISSN 2073-4360, Vol. 16, no 3, article id 426Article in journal (Refereed)
    Abstract [en]

    Hyperbranched polymers (HBPs) are widely applied nowadays as functional materials for biomedicine needs, nonlinear optics, organic semiconductors, etc. One of the effective and promising ways to synthesize HBPs is a polyaddition of AB2+A2+B4 monomers that is generated in the A2+CB2, AA′+B3, A2+B′B2, and A2+C2+B3 systems or using other approaches. It is clear that all the foundational features of HBPs that are manufactured by a polyaddition reaction are defined by the component composition of the monomer mixture. For this reason, we have designed a structural kinetic model of AB2+A2+B4 monomer mixture polyaddition which makes it possible to predict the impact of the monomer mixture’s composition on the molecular weight characteristics of hyperbranched polymers (number average (DPn) and weight average (DPw) degree of polymerization), as well as the degree of branching (DB) and gel point (pg). The suggested model also considers the possibility of a positive or negative substitution effect during polyaddition. The change in the macromolecule parameters of HBPs formed by polyaddition of AB2+A2+B4 monomers is described as an infinite system of kinetic equations. The solution for the equation system was found using the method of generating functions. The impact of both the component’s composition and the substitution effect during the polyaddition of AB2+A2+B4 monomers on structural and molecular weight HBP characteristics was investigated. The suggested model is fairly versatile; it makes it possible to describe every possible case of polyaddition with various monomer combinations, such as A2+AB2, AB2+B4, AB2, or A2+B4. The influence of each monomer type on the main characteristics of hyperbranched polymers that are obtained by the polyaddition of AB2+A2+B4 monomers has been investigated. Based on the results obtained, an empirical formula was proposed to estimate the pg = pA during the polyaddition of an AB2+A2+B4 monomer mixture: pg = pA = (−0.53([B]0/[A]0)1/2 + 0.78)υAB2 + (1/3)1/2([B]0/[A]0)1/2, where (1/3)1/2([B]0/[A]0)1/2 is the Flory equation for the A2+B4 polyaddition, [A]0 and [B]0 are the A and B group concentration from A2 and B4, respectively, and υAB2 is the mole fraction of the AB2 monomer in the mixture. The equation obtained allows us to accurately predict the pg value, with an AB2 monomer content of up to 80%.

  • 21.
    Koemmling, Anja
    et al.
    Bundesanstalt Mat Forsch & Prufung, D-12200 Berlin, Germany..
    Jaunich, Matthias
    Bundesanstalt Mat Forsch & Prufung, D-12200 Berlin, Germany..
    Pourmand, Payam
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Wolff, Dietmar
    Bundesanstalt Mat Forsch & Prufung, D-12200 Berlin, Germany..
    Hedenqvist, Mikael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Analysis of O-Ring Seal Failure under Static Conditions and Determination of End-of-Lifetime Criterion2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 8, article id 1251Article in journal (Refereed)
    Abstract [en]

    Determining a suitable and reliable end-of-lifetime criterion for O-ring seals is an important issue for long-term seal applications. Therefore, seal failure of ethylene propylene diene rubber (EPDM) and hydrogenated nitrile butadiene rubber (HNBR) O-rings aged in the compressed state at 125 degrees C and at 150 degrees C for up to 1.5 years was analyzed and investigated under static conditions, using both non-lubricated and lubricated seals. Changes of the material properties were analyzed with dynamic-mechanical analysis and permeability experiments. Indenter modulus measurements were used to investigate DLO effects. It became clear that O-rings can remain leak-tight under static conditions even when material properties have already degraded considerably, especially when adhesion effects are encountered. As a feasible and reliable end-of-lifetime criterion for O-ring seals under static conditions should include a safety margin for slight dimensional changes, a modified leakage test involving a small and rapid partial decompression of the seal was introduced that enabled determining a more realistic but still conservative end-of-lifetime criterion for an EPDM seal.

  • 22.
    Li, Jingwen
    et al.
    Zhejiang Ocean Univ, Sch Food & Pharm, Zhoushan 316022, Peoples R China..
    Zhang, Feifan
    Zhejiang Ocean Univ, Sch Food & Pharm, Zhoushan 316022, Peoples R China..
    Zhong, Yaqi
    Zhejiang Ocean Univ, Sch Food & Pharm, Zhoushan 316022, Peoples R China..
    Zhao, Yadong
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. Zhejiang Ocean Univ, Sch Food & Pharm, Zhoushan 316022, Peoples R China..
    Gao, Pingping
    Zhejiang Ocean Univ, Sch Food & Pharm, Zhoushan 316022, Peoples R China..
    Tian, Fang
    Zhejiang Ocean Univ, Sch Food & Pharm, Zhoushan 316022, Peoples R China..
    Zhang, Xianhui
    Xiamen Univ, Inst Electromagnet & Acoust, Fujian Prov Key Lab Plasma & Magnet Resonance, Xiamen 361005, Peoples R China..
    Zhou, Rusen
    Univ Sydney, Sch Chem & Biomol Engn, Sydney, NSW 2006, Australia..
    Cullen, Patrick J.
    Univ Sydney, Sch Chem & Biomol Engn, Sydney, NSW 2006, Australia..
    Emerging Food Packaging Applications of Cellulose Nanocomposites: A Review2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 19, article id 4025Article, review/survey (Refereed)
    Abstract [en]

    Cellulose is the most abundant biopolymer on Earth, which is synthesized by plants, bacteria, and animals, with source-dependent properties. Cellulose containing beta-1,4-linked D-glucoses further assembles into hierarchical structures in microfibrils, which can be processed to nanocellulose with length or width in the nanoscale after a variety of pretreatments including enzymatic hydrolysis, TEMPO-oxidation, and carboxymethylation. Nanocellulose can be mainly categorized into cellulose nanocrystal (CNC) produced by acid hydrolysis, cellulose nanofibrils (CNF) prepared by refining, homogenization, microfluidization, sonification, ball milling, and the aqueous counter collision (ACC) method, and bacterial cellulose (BC) biosynthesized by the Acetobacter species. Due to nontoxicity, good biodegradability and biocompatibility, high aspect ratio, low thermal expansion coefficient, excellent mechanical strength, and unique optical properties, nanocellulose is utilized to develop various cellulose nanocomposites through solution casting, Layer-by-Layer (LBL) assembly, extrusion, coating, gel-forming, spray drying, electrostatic spinning, adsorption, nanoemulsion, and other techniques, and has been widely used as food packaging material with excellent barrier and mechanical properties, antibacterial activity, and stimuli-responsive performance to improve the food quality and shelf life. Under the driving force of the increasing green food packaging market, nanocellulose production has gradually developed from lab-scale to pilot- or even industrial-scale, mainly in Europe, Africa, and Asia, though developing cost-effective preparation techniques and precisely tuning the physicochemical properties are key to the commercialization. We expect this review to summarise the recent literature in the nanocellulose-based food packaging field and provide the readers with the state-of-the-art of this research area.

  • 23.
    Liu, Xiaoyan
    et al.
    Shaanxi Normal Univ, Sch Chem & Chem Engn, Xian 710062, Peoples R China..
    Claesson, Per M.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Bioinspired Bottlebrush Polymers for Aqueous Boundary Lubrication2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 13, p. 2724-, article id 2724Article, review/survey (Refereed)
    Abstract [en]

    An extremely efficient lubrication system is achieved in synovial joints by means of bio-lubricants and sophisticated nanostructured surfaces that work together. Molecular bottlebrush structures play crucial roles for this superior tribosystem. For example, lubricin is an important bio-lubricant, and aggrecan associated with hyaluronan is important for the mechanical response of cartilage. Inspired by nature, synthetic bottlebrush polymers have been developed and excellent aqueous boundary lubrication has been achieved. In this review, we summarize recent experimental investigations of the interfacial lubrication properties of surfaces coated with bottlebrush bio-lubricants and bioinspired bottlebrush polymers. We also discuss recent advances in understanding intermolecular synergy in aqueous lubrication including natural and synthetic polymers. Finally, opportunities and challenges in developing efficient aqueous boundary lubrication systems are outlined.

  • 24.
    Melilli, Giuseppe
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Carmagnola, Irene
    Politecn Torino, Dept Mech & Aerosp Engn, Cso Duca Abruzzi 24, I-10129 Turin, Italy.;Politecn Torino, POLITO BIOMed LAB, I-10129 Turin, Italy..
    Tonda-Turo, Chiara
    Politecn Torino, Dept Mech & Aerosp Engn, Cso Duca Abruzzi 24, I-10129 Turin, Italy.;Politecn Torino, POLITO BIOMed LAB, I-10129 Turin, Italy..
    Pirri, Fabrizio
    Politecn Torino, POLITO BIOMed LAB, I-10129 Turin, Italy.;Politecn Torino, Dept Appl Sci & Technol, Cso Duca Abruzzi 24, I-10129 Turin, Italy..
    Ciardelli, Gianluca
    Politecn Torino, Dept Mech & Aerosp Engn, Cso Duca Abruzzi 24, I-10129 Turin, Italy.;Politecn Torino, POLITO BIOMed LAB, I-10129 Turin, Italy..
    Sangermano, Marco
    Politecn Torino, POLITO BIOMed LAB, I-10129 Turin, Italy.;Politecn Torino, Dept Appl Sci & Technol, Cso Duca Abruzzi 24, I-10129 Turin, Italy..
    Hakkarainen, Minna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Chiappone, Annalisa
    Politecn Torino, POLITO BIOMed LAB, I-10129 Turin, Italy.;Politecn Torino, Dept Appl Sci & Technol, Cso Duca Abruzzi 24, I-10129 Turin, Italy..
    DLP 3D Printing Meets Lignocellulosic Biopolymers: Carboxymethyl Cellulose Inks for 3D Biocompatible Hydrogels2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 8, article id 1655Article in journal (Refereed)
    Abstract [en]

    The development of new bio-based inks is a stringent request for the expansion of additive manufacturing towards the development of 3D-printed biocompatible hydrogels. Herein, methacrylated carboxymethyl cellulose (M-CMC) is investigated as a bio-based photocurable ink for digital light processing (DLP) 3D printing. CMC is chemically modified using methacrylic anhydride. Successful methacrylation is confirmed by(1)H NMR and FTIR spectroscopy. Aqueous formulations based on M-CMC/lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator and M-CMC/Dulbecco's Modified Eagle Medium (DMEM)/LAP show high photoreactivity upon UV irradiation as confirmed by photorheology and FTIR. The same formulations can be easily 3D-printed through a DLP apparatus to produce 3D shaped hydrogels with excellent swelling ability and mechanical properties. Envisaging the application of the hydrogels in the biomedical field, cytotoxicity is also evaluated. The light-induced printing of cellulose-based hydrogels represents a significant step forward in the production of new DLP inks suitable for biomedical applications.

  • 25.
    Mohammadkhani, Ghasem
    et al.
    Univ Borås, Swedish Ctr Resource Recovery, S-50190 Borås, Sweden..
    Kumar Ramamoorthy, Sunil
    Univ Borås, Swedish Ctr Resource Recovery, S-50190 Borås, Sweden..
    Adolfsson, Karin H.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Mahboubi, Amir
    Univ Borås, Swedish Ctr Resource Recovery, S-50190 Borås, Sweden..
    Hakkarainen, Minna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Zamani, Akram
    Univ Borås, Swedish Ctr Resource Recovery, S-50190 Borås, Sweden..
    New Solvent and Coagulating Agent for Development of Chitosan Fibers by Wet Spinning2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 13, p. 2121-, article id 2121Article in journal (Refereed)
    Abstract [en]

    Adipic acid was evaluated as a novel solvent for wet spinning of chitosan fibers. A solvent with two carboxyl groups could act as a physical crosslinker between the chitosan chains, resulting in improved properties of the fibers. The performance of adipic acid was compared with conventional solvents, i.e., lactic, citric, and acetic acids. Chitosan solutions were injected into a coagulation bath to form monofilaments. Sodium hydroxide (NaOH) and its mixture with ethanol (EtOH) were used as coagulation agents. Scanning electron microscopy confirmed the formation of uniform chitosan monofilaments with an even surface when using adipic acid as solvent. These monofilaments generally showed higher mechanical strength compared to that of monofilaments produced using conventional solvents. The highest Young's modulus, 4.45 GPa, was recorded for adipic acid monofilaments coagulated in NaOH-EtOH. This monofilament also had a high tensile strength of 147.9 MPa. Furthermore, taking advantage of chitosan insolubility in sulfuric acid (H2SO4) at room temperature, chitosan fibers were successfully formed upon coagulation in H2SO4-EtOH. The dewatering of fibers using EtOH before drying resulted in a larger fiber diameter and lower mechanical strength. Adipic acid fibers made without dehydration illustrated 18% (for NaOH), 46% (for NaOH-EtOH), and 91% (for H2SO4-EtOH) higher tensile strength compared to those made with dehydration.

  • 26.
    Mourad, Abdel Hamid, I
    et al.
    United Arab Emirate Univ, Coll Engn, Mech Engn Dept, Al Ain 15551, U Arab Emirates.;Helwan Univ, Fac Engn, Mech Design Dept, Cairo 11795, Egypt..
    Cherupurakal, Nizamudeen
    United Arab Emirate Univ, Coll Engn, Mech Engn Dept, Al Ain 15551, U Arab Emirates..
    Hafeez, Farrukh
    Univ Birmingham, Dept Mech Engn, Dubai 341799, U Arab Emirates..
    Barsoum, Imad
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics. Khalifa Univ, Dept Mech Engn, Abu Dhabi 127788, U Arab Emirates.
    Genena, Farah A.
    United Arab Emirate Univ, Coll Engn, Mech Engn Dept, Al Ain 15551, U Arab Emirates..
    Al Mansoori, Mouza S.
    United Arab Emirate Univ, Coll Engn, Mech Engn Dept, Al Ain 15551, U Arab Emirates..
    Al Marzooqi, Lamia A.
    United Arab Emirate Univ, Coll Engn, Mech Engn Dept, Al Ain 15551, U Arab Emirates..
    Impact Strengthening of Laminated Kevlar/Epoxy Composites by Nanoparticle Reinforcement2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 12, article id 2814Article in journal (Refereed)
    Abstract [en]

    Herein, we report the fabrication and characterization of high-strength Kevlar epoxy composite sheets for structural application. This process includes optimization of the curing conditions of composite preparation, such as curing time and temperature, and the incorporation of nanofillers, such as aluminum oxide (Al2O3), silicon carbide (SiC), and multi-walled carbon nanotubes (MWCNT) in different weight percentages. Differential scanning calorimetry (DSC) was utilized to investigate the thermal stability and curing behavior of the epoxy, finding that a minimum of 5 min is required for complete curing under an optimized temperature of 170 degrees C. Moreover, mechanical characterization, including flexural and drop-weight tests, were performed and found to be in good agreement with the DSC results. Our results show that nanofiller incorporation improves the mechanical properties of Kevlar epoxy composites. Among the tested samples, 0.5% MWCNT incorporation obtained the highest mechanical strength.

  • 27.
    Nejstroem, Malin
    et al.
    Mid Sweden Univ, FSCN, Surface & Colloid Engn, S-85170 Sundsvall, Sweden.;Nouryon, S-85467 Sundsvall, Sweden..
    Andreasson, Bo
    Nouryon, S-85467 Sundsvall, Sweden..
    Sjölund, Johanna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology.
    Eivazi, Alireza
    Mid Sweden Univ, FSCN, Surface & Colloid Engn, S-85170 Sundsvall, Sweden..
    Svanedal, Ida
    Mid Sweden Univ, FSCN, Surface & Colloid Engn, S-85170 Sundsvall, Sweden..
    Edlund, Hakan
    Mid Sweden Univ, FSCN, Surface & Colloid Engn, S-85170 Sundsvall, Sweden..
    Norgren, Magnus
    Mid Sweden Univ, FSCN, Surface & Colloid Engn, S-85170 Sundsvall, Sweden..
    On Structural and Molecular Order in Cellulose Acetate Butyrate Films2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 9, article id 2205Article in journal (Refereed)
    Abstract [en]

    Cellulose acetate butyrate (CAB) is a possible candidate, being a raw material derived from renewable resources, to replace fossil-based materials. This is due to its thermoplastic properties and the relative ease with which it could be implemented within the existing industry. With a significant amount of variation in CAB on the market today, a knowledge gap has been identified regarding the understanding of the polymer structural arrangement in films. This relates to the underlying mechanisms that regulate CAB film material properties, insights that are important in product development. In this study, commercially available CAB was investigated with XRD, SEM, AFM, and TOPEM DSC in order to obtain physicochemical information related to its micro-structural features in solvent-cast films. The film-forming ability relates mostly to the number of hydroxyl groups, and the semi-crystallinity of the films depends on the type and position of the side groups along the cellulose backbone. The appearance of signs of possible cholesteric ordering in the films could be connected to higher amounts of hydroxyl groups along the backbone that disturb the helix arrangement, while the overall order was primarily related to the butyrate substitution and secondarily related to the molecular weight of the particular CAB studied. Cold crystallization was also observed in one CAB sample.

  • 28. Noe, Camilla
    et al.
    Hakkarainen, Minna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Sangermano, Marco
    Cationic UV-Curing of Epoxidized Biobased Resins2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 1, article id 89Article, review/survey (Refereed)
    Abstract [en]

    Epoxy resins are among the most important building blocks for fabrication of thermosets for many different applications thanks to their superior thermo-mechanical properties and chemical resistance. The recent concerns on the environmental problems and the progressive depletion of petroleum feedstocks have drawn the research interest in finding biobased alternatives. Many curing techniques can be used to obtain the final crosslinked thermoset networks. The UV-curing technology can be considered the most environmentally friendly because of the absence of volatile organic compound (VOC) emissions and mild curing conditions. This review provides an overview of the state of the art of bio-based cationic UV-curable epoxy resins. Particular focus has been given to the sources of the bio-based epoxy monomers and the applications of the obtained products.

  • 29. Noe, Camilla
    et al.
    Tonda-Turo, Chiara
    Chiappone, Annalisa
    Sangermano, Marco
    Hakkarainen, Minna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Light Processable Starch Hydrogels2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 6, article id 1359Article in journal (Refereed)
    Abstract [en]

    Light processable hydrogels were successfully fabricated by utilizing maize starch as raw material. To render light processability, starch was gelatinized and methacrylated by simple reaction with methacrylic anhydride. The methacrylated starch was then evaluated for its photocuring reactivity and 3D printability by digital light processing (DLP). Hydrogels with good mechanical properties and biocompatibility were obtained by direct curing from aqueous solution containing lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) as photo-initiator. The properties of the hydrogels were tunable by simply changing the concentration of starch in water. Photo-rheology showed that the formulations with 10 or 15 wt% starch started curing immediately and reached G' plateau after only 60 s, while it took 90 s for the 5 wt% formulation. The properties of the photocured hydrogels were further characterized by rheology, compressive tests, and swelling experiments. Increasing the starch content from 10 to 15 wt% increased the compressive stiffness from 13 to 20 kPa. This covers the stiffness of different body tissues giving promise for the use of the hydrogels in tissue engineering applications. Good cell viability with human fibroblast cells was confirmed for all three starch hydrogel formulations indicating no negative effects from the methacrylation or photo-crosslinking reaction. Finally, the light processability of methacrylated starch by digital light processing (DLP) 3D printing directly from aqueous solution was successfully demonstrated. Altogether the results are promising for future application of the hydrogels in tissue engineering and as cell carriers.

  • 30.
    Normand, Myriam Le
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Rietzler, Barbara
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Fibre Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Wood Chemistry and Pulp Technology.
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Ek, Monica
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Macromolecular Model of the Pectic Polysaccharides Isolated from the Bark of Norway Spruce (Picea abies)2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 7, article id 1106Article in journal (Refereed)
    Abstract [en]

    The bark of Norway spruce (Picea abies) contains up to 13% pectins that can be extracted by pressurized hot water, which constitute a valuable renewable resource in second-generation lignocellulosic biorefineries. This article proposes, for the first time, structural molecular models for the pectins present in spruce bark. Pectin fractions of tailored molar masses were obtained by fractionation of the pressurized hot water extract of the inner bark using preparative size-exclusion chromatography. The monosaccharide composition, average molar mass distribution, and the glycosidic linkage patterns were analyzed for each fraction. The pectin fraction with high molecular weight (M-w of 59,000 Da) contained a highly branched RG-I domain, which accounted for 80% of the fraction and was mainly substituted with arabinan and arabinogalactan (type I and II) side chains. On the other hand, the fractions with lower molar masses (M-w = 15,000 and 9000 Da) were enriched with linear homogalacturonan domains, and also branched arabinan populations. The integration of the analytical information from the macromolecular size distributions, domain composition, and branch lengths of each pectin fraction, results in a comprehensive understanding of the macromolecular architecture of the pectins extracted from the bark of Norway spruce. This paves the way for the valorization of spruce bark pectic polymers in targeted applications based on their distinct polymeric structures and properties.

  • 31.
    Oliaei, Erfan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Biocomposites. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Material and Surface Design Department, Bioeconomy and Health Division, RISE Research Institutes of Sweden, Stockholm, SE-114 86, Sweden.
    Lindström, Tom
    SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA..
    Berglund, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Biocomposites. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Sustainable development of hot-pressed all-lignocellulose composites—comparing wood fibers and nanofibers2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 16, article id 2747Article, review/survey (Refereed)
    Abstract [en]

    Low-porosity materials based on hot-pressed wood fibers or nanocellulose fibrils (no polymer matrix) represent a new concept for eco-friendly materials with interesting mechanical properties. For the replacement of fossil-based materials, physical properties of wood fiber materials need to be improved. In addition, the carbon footprint and cumulative energy required to produce the material also needs to be reduced compared with fossil-based composites, e.g., glass fiber composites. Lignin-containing fibers and nanofibers are of high yield and special interest for development of more sustainable materials technologies. The present mini-review provides a short analysis of the potential. Different extraction routes of lignin-containing wood fibers are discussed, different processing methods, and the properties of resulting fiber materials. Comparisons are made with analogous lignin-containing nanofiber materials, where mechanical properties and eco-indicators are emphasized. Higher lignin content may promote eco-friendly attributes and improve interfiber or interfibril bonding in fiber materials, for improved mechanical performance.

  • 32. Ossipov, Dmitri A.
    et al.
    Lüchow, Mads
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Malkoch, Michael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Differentiating Co-Delivery of Bisphosphonate and Simvastatin by Self-Healing Hyaluronan Hydrogel Formed by Orthogonal "Clicks": An In-Vitro Assessment2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 13, p. 2106-, article id 2106Article in journal (Refereed)
    Abstract [en]

    Due to its unique properties resembling living tissues, hydrogels are attractive carriers for the localized and targeted delivery of various drugs. Drug release kinetics from hydrogels are commonly controlled by network properties and the drug-network interactions. However, and simultaneously, the programmable delivery of multiple drugs with opposing properties (hydrophilicity, molecular weight, etc.) from hydrogels with determined network properties is still challenging. Herein, we describe the preparation of injectable self-healing hyaluronic acid (HA) hydrogels that release hydrophobic simvastatin and hydrophilic aminobisphosphonate (BP) drugs independently in response to acidic and thiol-containing microenvironments, respectively. We apply a prodrug strategy to BP by conjugating it to HA via a self-immolative disulfide linker that is stable in the blood plasma and is cleavable in the cytoplasm. Moreover, we utilize HA-linked BP ligands to reversibly bind Ca2+ ions and form coordination hydrogels. Hydrazone coupling of hydrophobic ligands to HA permits the encapsulation of simvastatin molecules in the resulting amphiphilic HA derivative and the subsequent acid-triggered release of the drug. The conjugation of BP and hydrophobic ligands to HA enables preparation of both bulk self-healing hydrogels and nanogels. Moreover, the developed hydrogel system is shown to be multi-responsive by applying orthogonally cleavable linkers. The presented hydrogel is a potential candidate for the combination treatment of osteoporosis and bone cancers as well as for bone tissue regeneration since it can deliver bone anabolic and anti-catabolic agents in response to bone diseases microenvironments.

  • 33.
    Paidi, Murali Krishna
    et al.
    Council Sci & Ind Res CSIR, CSIR Cent Salt & Marine Chem Res Inst, GB Marg, Bhavnagar 364002, Gujarat, India.;Acad Sci & Innovat Res AcSIR, Ghaziabad 201002, India..
    Polisetti, Veerababu
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials. Council Sci & Ind Res CSIR, CSIR Cent Salt & Marine Chem Res Inst, GB Marg, Bhavnagar 364002, Gujarat, India..
    Damarla, Krishnaiah
    Council Sci & Ind Res CSIR, CSIR Cent Salt & Marine Chem Res Inst, GB Marg, Bhavnagar 364002, Gujarat, India..
    Singh, Puyam Sobhindro
    Council Sci & Ind Res CSIR, CSIR Cent Salt & Marine Chem Res Inst, GB Marg, Bhavnagar 364002, Gujarat, India..
    Mandal, Subir Kumar
    Council Sci & Ind Res CSIR, CSIR Cent Salt & Marine Chem Res Inst, GB Marg, Bhavnagar 364002, Gujarat, India.;Acad Sci & Innovat Res AcSIR, Ghaziabad 201002, India..
    Ray, Paramita
    Council Sci & Ind Res CSIR, CSIR Cent Salt & Marine Chem Res Inst, GB Marg, Bhavnagar 364002, Gujarat, India..
    3D Natural Mesoporous Biosilica-Embedded Polysulfone Made Ultrafiltration Membranes for Application in Separation Technology2022In: Polymers, E-ISSN 2073-4360, Vol. 14, no 9, article id 1750Article in journal (Refereed)
    Abstract [en]

    Diatoms are the most abundant photosynthetic microalgae found in all aquatic habitats. In the extant study, the spent biomass (after lipid extraction) of the centric marine diatom Thalassiosira lundiana CSIRCSMCRI 001 was subjected to acid digestion for the extraction of micro composite inorganic biosilica. Then, the resulting three-dimensional mesoporous biosilica material (diatomite) was used as a filler in polysulfone (PSF) membrane preparation by phase inversion. The fabricated PSF/diatomite composite membranes were characterized by SEM-EDX, TGA, and ATR-IR, and their performances were evaluated. The number of pores and pore size were increased on the membrane surface with increased diatomite in the composite membranes as compared to the control. The diatomite composite membranes had high hydrophilicity and thermal stability, lower surface roughness, and excellent water permeability. Membranes with high % diatomite, i.e., PSF/Dia(0.5), had a maximum water flux of 806.8 LMH (Liter/m(2)/h) at 20 psi operating pressure. High-diatomite content membranes also exhibited the highest rejection of BSA protein (98.5%) and rhodamine 6G (94.8%). Similarly, in biomedical rejection tests, the PSF/Dia(0.5) membrane exhibited a maximum rejection of ampicillin (75.84%) and neomycin (85.88%) at 20 Psi pressure. In conclusion, the mesoporous inorganic biosilica material was extracted from spent biomass of diatom and successfully used in filtration techniques. The results of this study could enhance the application of natural biogenic porous silica materials in wastewater treatment for water recycling.

  • 34.
    Perez-Puyana, Victor M.
    et al.
    Univ Seville, Escuela Politecn Super, Fac Quim, Dept Ingn Quim, Seville 41012, Spain..
    Capezza, Antonio Jose
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    Newson, William R.
    Swedish Univ Agr Sci, Dept Plant Breeding, Box 190, SE-23422 Lomma, Sweden..
    Bengoechea, Carlos
    Univ Seville, Escuela Politecn Super, Fac Quim, Dept Ingn Quim, Seville 41012, Spain..
    Johansson, Eva
    Swedish Univ Agr Sci, Dept Plant Breeding, Box 190, SE-23422 Lomma, Sweden..
    Guerrero, Antonio
    Univ Seville, Escuela Politecn Super, Fac Quim, Dept Ingn Quim, Seville 41012, Spain..
    Hedenqvist, Mikael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Functionalization Routes for Keratin from Poultry Industry Side-Streams-Towards Bio-Based Absorbent Polymers2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 2, p. 351-, article id 351Article in journal (Refereed)
    Abstract [en]

    Keratin is a largely available protein that can be obtained from the ca. 3 million tons of feathers that the European poultry industry produces as a side-stream. Here, the functionalization of keratin from poultry feathers was evaluated using a one- versus two-stage process using two functionalization agents (succinic anhydride-SA and ethylene dianhydride-EDTAD). The functionalization resulted in the keratin having improved liquid swelling capacities, reaching up to 400%, 300%, and 85% increase in water, saline, and blood, respectively, compared to non-functionalized keratin. The highest swelling was obtained for samples functionalized with EDTAD (one-stage process), while the highest saline uptake was noted for samples processed with 25 wt% SA (two-stage process). Swelling kinetics modeling indicated that the water uptake by the functionalized samples takes place in two steps, and the EDTAD samples showed the highest diffusivity. It is demonstrated that the one-stage functionalization of keratin utilizing EDTAD results in better performance than two-stages, which allows for resource-saving and, thereby, protecting the environment. The results show some potential for the keratin to be utilized as liquid absorbent materials in water, saline, and blood uptake applications. Using keratin from side-streams is an advantage from a sustainability perspective over biomacromolecules that need to be extracted from virgin biomass.

  • 35.
    Pezzana, Lorenzo
    et al.
    Politecn Torino, Dept Appl Sci & Technol, Corso Duca Abruzzi 24, I-10129 Turin, Italy..
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sangermano, Marco
    Politecn Torino, Dept Appl Sci & Technol, Corso Duca Abruzzi 24, I-10129 Turin, Italy..
    UV-Curable Bio-Based Polymers Derived from Industrial Pulp and Paper Processes2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 9, article id 1530Article, review/survey (Refereed)
    Abstract [en]

    Bio-based monomers represent the future market for polymer chemistry, since the political economics of different states promote green ventures toward more sustainable materials and processes. Industrial pulp and paper processing represent a large market that could advance the use of by-products to avoid waste production and reduce pollution. Lignin represents the most available side product that can be used to produce a bio-based monomer. This review is concentrated on the possibility of using bio-based monomer derivates from pulp and the paper industry for UV-curing processing. UV-curing represents the new frontier for thermoset production, allowing a fast reaction cure, less energy demand, and the elimination of solvent. The growing demand for new monomers increases research in the environmental field to substitute for petroleum-based products. This review provides an overview of the main monomers and relative families of compounds derived from industrial processes that are suitable for UV-curing. Particular focus is given to the developments reached in the last few years concerning lignin, rosin and terpenes and the related possible applications of these in UV-curing chemistry.

  • 36.
    Sanchez, Carmen
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Wåhlander, Martin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Karlsson, Mattias E.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Quintero, Diana C. Marin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Hillborg, Henrik
    ABB Power Technol, SE-72178 Vasteras, Sweden..
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Nilsson, Fritjof
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Characterization of Reduced and Surface-Modified Graphene Oxide in Poly(Ethylene-co-Butyl Acrylate) Composites for Electrical Applications2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 4, article id 740Article in journal (Refereed)
    Abstract [en]

    Promising electrical field grading materials (FGMs) for high-voltage direct-current (HVDC) applications have been designed by dispersing reduced graphene oxide (rGO) grafted with relatively short chains of poly (n-butyl methacrylate) (PBMA) in a poly(ethylene-co-butyl acrylate) (EBA) matrix. All rGO-PBMA composites with a filler fraction above 3 vol.% exhibited a distinct non-linear resistivity with increasing electric field; and it was confirmed that the resistivity could be tailored by changing the PBMA graft length or the rGO filler fraction. A combined image analysis- and Monte-Carlo simulation strategy revealed that the addition of PBMA grafts improved the enthalpic solubility of rGO in EBA; resulting in improved particle dispersion and more controlled flake-to-flake distances. The addition of rGO and rGO-PBMAs increased the modulus of the materials up to 200% and the strain did not vary significantly as compared to that of the reference matrix for the rGO-PBMA-2 vol.% composites; indicating that the interphase between the rGO and EBA was subsequently improved. The new composites have comparable electrical properties as today's commercial FGMs; but are lighter and less brittle due to a lower filler fraction of semi-conductive particles (3 vol.% instead of 30-40 vol.%).

  • 37.
    Singha, Shuvra
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Hedenqvist, Mikael S.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymeric Materials.
    A Review on Barrier Properties of Poly(Lactic Acid)/Clay Nanocomposites2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 5, article id 1095Article, review/survey (Refereed)
    Abstract [en]

    Poly(lactic acid) (PLA) is considered to be among the best biopolymer substitutes for the existing petroleum-based polymers in the field of food packaging owing to its renewability, biodegradability, non-toxicity and mechanical properties. However, PLA displays only moderate barrier properties to gases, vapors and organic compounds, which can limit its application as a packaging material. Hence, it becomes essential to understand the mass transport properties of PLA and address the transport challenges. Significant improvements in the barrier properties can be achieved by incorporating two-dimensional clay nanofillers, the planes of which create tortuosity to the diffusing molecules, thereby increasing the effective length of the diffusion path. This article reviews the literature on barrier properties of PLA/clay nanocomposites. The important PLA/clay nanocomposite preparation techniques, such as solution intercalation, melt processing and in situ polymerization, are outlined followed by an extensive account of barrier performance of nanocomposites drawn from the literature. Fundamentals of mass transport phenomena and the factors affecting mass transport are also presented. Furthermore, mathematical models that have been proposed/used to predict the permeability in polymer/clay nanocomposites are reviewed and the extent to which the models are validated in PLA/clay composites is discussed.

  • 38.
    Sterner, Martin
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Edlund, Ulrica
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Hybrid Filaments from Saccaharina lattisima Biomass: Engineering of Alginate Properties with Maleic Anhydride Grafted Linseed Oil2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 5, article id 836Article in journal (Refereed)
    Abstract [en]

    Linseed oil was graft modified with maleic anhydride and introduced into alginate by co-extrusion, producing alginate hybrid filaments. A straightforward grafting of maleic anhydride onto the oil backbone produced the modified oil. Additional esterification with n-dodecanol was also investigated. The structures of the modified oils were verified with 2D-NMR. The modified oil was mixed with alginate and extruded into CaCl2, forming thin filaments with diameters in the 130-260 mu m range. The impact of oil integration into the alginate filaments was assessed, with special emphasis on stress-at-break, and compared to values predicted by an empirical model relating the "stress to alginate concentration" ratio to prevailing conditions during filament drawing. Analogous alginate filaments were prepared with hydrochloric-, oxalic- and phytic acid calcium salts for comparison with alginate-oil hybrids to reveal the induced impact, with respect to the composition and charge, on the tensile performance.

  • 39.
    Sultana, Nazmun
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology. Organic Chemistry, Chemistry, and Chemical Engineering, Chalmers University of Technology, Kemigården 4, Gothenburg, SE-412 96, Sweden, Kemigården 4; FibRe—Centre for Lignocellulose-Based Thermoplastics.
    Edlund, Ulrica
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Guria, Chandan
    Department of Petroleum Engineering, Indian Institute of Technology (IIT-Indian School of Mines), Dhanbad, 826 004, India.
    Westman, Gunnar
    Organic Chemistry, Chemistry, and Chemical Engineering, Chalmers University of Technology, Kemigården 4, Gothenburg, SE-412 96, Sweden, Kemigården 4; FibRe—Centre for Lignocellulose-Based Thermoplastics, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, SE-412 96, Sweden.
    Kinetics of Periodate-Mediated Oxidation of Cellulose2024In: Polymers, E-ISSN 2073-4360, Vol. 16, no 3, article id 381Article in journal (Refereed)
    Abstract [en]

    The oxidation of cellulose to dialdehyde cellulose (DAC) is a process that has received increased interest during recent years. Herein, kinetic modeling of the reaction with sodium periodate as an oxidizing agent was performed to quantify rate-limiting steps and overall kinetics of the cellulose oxidation reaction. Considering a pseudo-first-order reaction, a general rate expression was derived to elucidate the impact of pH, periodate concentration, and temperature on the oxidation of cellulose and concurrent formation of cellulose degradation products. Experimental concentration profiles were utilized to determine the rate constants for the formation of DAC (k1), degradation constant of cellulose (k2), and degradation of DAC (k3), confirming that the oxidation follows a pseudo-first-order reaction. Notably, the increase in temperature has a more pronounced effect on k1 compared to the influence of IO4− concentration. In contrast, k2 and k3 display minimal changes in response to IO4− concentration but increase significantly with increasing temperature. The kinetic model developed may help with understanding the rate-limiting steps and overall kinetics of the cellulose oxidation reaction, providing valuable information for optimizing the process toward a faster reaction with higher yield of the target product.

  • 40.
    Swensson, Beatrice
    et al.
    Chalmers Univ Technol, Dept Chem & Chem Engn, SE-41296 Gothenburg, Sweden..
    Larsson, Anette
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Chalmers Univ Technol, Dept Chem & Chem Engn, SE-41296 Gothenburg, Sweden.
    Hasani, Merima
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Chalmers Univ Technol, Dept Chem & Chem Engn, SE-41296 Gothenburg, Sweden..
    Probing Interactions in Combined Hydroxide Base Solvents for Improving Dissolution of Cellulose2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 6, article id 1310Article in journal (Refereed)
    Abstract [en]

    To further understand cellulose-solvent interactions in aqueous hydroxide solutions, cellulose behavior in aqueous solutions of NaOH combined with tetramethylammonium hydroxide (TMAH) or benzyltrimethylammonium hydroxide (Triton B), as well as urea, was investigated. The rheological properties of the solutions were assessed through flow sweeps at different temperatures, and the intermolecular interactions were probed using solvatochromic dyes. The results showed that NaOH combined with TMAH had synergistic effects on cellulose dissolution and was a better solvent for cellulose than the combination of NaOH with Triton B, in spite of the superior dissolution ability of Triton B alone. This somewhat unexpected finding shows that the base pair needs to be selected with care. Interestingly, addition of urea had no significant effect on the solvatochromic parameters or dissolution capacity of solutions of Triton B but rendered improved stability of solutions containing NaOH and/or TMAH. It seems that both urea and Triton B weaken the hydrophobic assembly effect of these solutions, but urea is excluded from interacting with cellulose in the presence of Triton B. This study provides further insight into dissolution of cellulose and the possibility of utilizing combinations of hydroxide bases to achieve improved solution properties.

  • 41.
    Vizcaíno-Vergara, María
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL. Queen Mary Univ London, Sch Engn & Mat Sci, Mile End Rd, London E1 4NS, England..
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Tunnicliffe, Lewis B.
    Birla Carbon, 1800 West Oak Commons Court, Marietta, GA 30062 USA..
    Busfield, James J. C.
    Queen Mary Univ London, Sch Engn & Mat Sci, Mile End Rd, London E1 4NS, England..
    Evolution of the Viscoelastic Properties of Filler Reinforced Rubber under Physical Aging at Room Temperature2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 7, article id 1806Article in journal (Refereed)
    Abstract [en]

    Filler reinforced rubber is widely used for engineering applications; therefore, a sound characterization of the effects of physical aging is crucial for accurately predicting its viscoelastic properties within its operational temperature range. Here, the torsion pendulum is used to monitor the evolution of the storage and loss modulus of carbon black filled samples for four days after a temperature drop to 30 degrees C. The storage modulus presents a continuous increase, while the loss modulus generally displays a steady decrease throughout the four days that each test was conducted. The relationship of the recovery rates with the carbon black properties is also studied, analysing its dependency on the particle size and aggregate structure. The evolution of the recovery rate seems to depend linearly on the surface area while the carbon black structure appears to have a much weaker influence on the physical aging behavior for the set of compounds tested. The obtained results corroborate the presence of physical aging at room temperature for filler rubber materials and the ability of the torsion pendulum to monitor the storage and loss modulus change, providing pivotal data on the influence of physical aging on the viscoelastic properties of the material.

  • 42.
    Wang, Bochao
    et al.
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL. Univ Sci & Technol China, Dept Modern Mech, CAS Ctr Excellence Complex Syst Mech, CAS Key Lab Mech Behav & Design Mat, Hefei 230027, Peoples R China..
    Kari, Leif
    KTH, School of Engineering Sciences (SCI), Engineering Mechanics, Fluid Mechanics and Engineering Acoustics, Marcus Wallenberg Laboratory MWL.
    Constitutive Model of Isotropic Magneto-Sensitive Rubber with Amplitude, Frequency, Magnetic and Temperature Dependence under a Continuum Mechanics Basis2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 3, article id 472Article in journal (Refereed)
    Abstract [en]

    A three-dimensional nonlinear constitutive model of the amplitude, frequency, magnetic and temperature dependent mechanical property of isotropic magneto-sensitive (MS) rubber is developed. The main components of MS rubber are an elastomer matrix and magnetizable particles. When a magnetic field is applied, the modulus of MS rubber increases, which is known as the magnetic dependence of MS rubber. In addition to the magnetic dependence, there are frequency, amplitude and temperature dependencies of the dynamic modulus of MS rubber. A continuum mechanical framework-based constitutive model consisting of a fractional standard linear solid (SLS) element, an elastoplastic element and a magnetic stress term of MS rubber is developed to depict the mechanical behavior of MS rubber. The novelty is that the amplitude, frequency, magnetic and temperature dependent mechancial properties of MS rubber are integrated into a whole constitutive model under the continuum mechanics frame. Comparison between the simulation and measurement results shows that the fitting effect of the developed model is very good. Therefore, the constitutive model proposed enables the prediction of the mechanical properties of MS rubber under various operating conditions with a high accuracy, which will drive MS rubber's application in engineering problems, especially in the area of MS rubber-based anti-vibration devices.

  • 43.
    Xing, Zhe
    et al.
    Lanzhou Univ, Sch Stomatol, Lanzhou 730000, Peoples R China.;Univ Bergen, Fac Med, Dept Clin Dent, N-5009 Bergen, Norway..
    Cai, Jiazheng
    Lanzhou Univ, Sch Stomatol, Lanzhou 730000, Peoples R China..
    Sun, Yang
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Cao, Mengnan
    Lanzhou Univ, Sch Stomatol, Lanzhou 730000, Peoples R China..
    Li, Yi
    Lanzhou Univ, Sch Stomatol, Lanzhou 730000, Peoples R China..
    Xue, Ying
    Univ Bergen, Fac Med, Dept Clin Dent, N-5009 Bergen, Norway..
    Finne-Wistrand, Anna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Kamal, Mustafa
    Univ Bergen, Fac Med, Dept Clin Dent, N-5009 Bergen, Norway..
    Altered Surface Hydrophilicity on Copolymer Scaffolds Stimulate the Osteogenic Differentiation of Human Mesenchymal Stem Cells2020In: Polymers, E-ISSN 2073-4360, Vol. 12, no 7, article id 1453Article in journal (Refereed)
    Abstract [en]

    Background: Recent studies have suggested that both poly(l-lactide-co-1,5-dioxepan-2-one) (or poly(LLA-co-DXO)) and poly(l-lactide-co-epsilon-caprolactone) (or poly(LLA-co-CL)) porous scaffolds are good candidates for use as biodegradable scaffold materials in the field of tissue engineering; meanwhile, their surface properties, such as hydrophilicity, need to be further improved. Methods: We applied several different concentrations of the surfactant Tween 80 to tune the hydrophilicity of both materials. Moreover, the modification was applied not only in the form of solid scaffold as a film but also a porous scaffold. To investigate the potential application for tissue engineering, human bone marrow mesenchymal stem cells (hMSCs) were chosen to test the effect of hydrophilicity on cell attachment, proliferation, and differentiation. First, the cellular cytotoxicity of the extracted medium from modified scaffolds was investigated on HaCaT cells. Then, hMSCs were seeded on the scaffolds or films to evaluate cell attachment, proliferation, and osteogenic differentiation. The results indicated a significant increasing of wettability with the addition of Tween 80, and the hMSCs showed delayed attachment and spreading. PCR results indicated that the differentiation of hMSCs was stimulated, and several osteogenesis related genes were up-regulated in the 3% Tween 80 group. Poly(LLA-co-CL) with 3% Tween 80 showed an increased messenger Ribonucleic acid (mRNA) level of late-stage markers such as osteocalcin (OC) and key transcription factor as runt related gene 2 (Runx2). Conclusion: A high hydrophilic scaffold may speed up the osteogenic differentiation for bone tissue engineering.

  • 44.
    Xing, Zhe
    et al.
    Lanzhou Univ, Sch Stomatol, Lanzhou 730000, Peoples R China.;Univ Bergen, Dept Clin Dent, Fac Med, N-5009 Bergen, Norway..
    Jiang, Xiaofeng
    Lanzhou Univ, Sch Stomatol, Lanzhou 730000, Peoples R China..
    Si, Qingzong
    Lanzhou Univ, Sch Stomatol, Lanzhou 730000, Peoples R China..
    Finne Wistrand, Anna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Polymer Technology.
    Liu, Bin
    Lanzhou Univ, Sch Stomatol, Lanzhou 730000, Peoples R China..
    Xue, Ying
    Univ Bergen, Dept Clin Dent, Fac Med, N-5009 Bergen, Norway..
    Mustafa, Kamal
    Univ Bergen, Dept Clin Dent, Fac Med, N-5009 Bergen, Norway..
    Endochondral Ossification Induced by Cell Transplantation of Endothelial Cells and Bone Marrow Stromal Cells with Copolymer Scaffold Using a Rat Calvarial Defect Model2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 9, article id 1521Article in journal (Refereed)
    Abstract [en]

    It has been recently reported that, in a rat calvarial defect model, adding endothelial cells (ECs) to a culture of bone marrow stromal cells (BMSCs) significantly enhanced bone formation. The aim of this study is to further investigate the ossification process of newly formed osteoid and host response to the poly(L-lactide-co-1,5-dioxepan-2-one) [poly(LLA-co-DXO)] scaffolds based on previous research. Several different histological methods and a PCR Array were applied to evaluate newly formed osteoid after 8 weeks after implantation. Histological results showed osteoid formed in rat calvarial defects and endochondral ossification-related genes, such as dentin matrix acidic phosphoprotein 1 (Dmp1) and collagen type II, and alpha 1 (Col2a1) exhibited greater expression in the CO (implantation with BMSC/EC/Scaffold constructs) than the BMSC group (implantation with BMSC/Scaffold constructs) as demonstrated by PCR Array. It was important to notice that cartilage-like tissue formed in the pores of the copolymer scaffolds. In addition, multinucleated giant cells (MNGCs) were observed surrounding the scaffold fragments. It was concluded that the mechanism of ossification might be an endochondral ossification process when the copolymer scaffolds loaded with co-cultured ECs/BMSCs were implanted into rat calvarial defects. MNGCs were induced by the poly(LLA-co-DXO) scaffolds after implantation, and more specific in vivo studies are needed to gain a better understanding of host response to copolymer scaffolds.

  • 45.
    Zhao, Yadong
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Tagami, Ayumu
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Dobele, Galina
    Latvian State Inst Wood Chem, 27 Dzerbenes Str, LV-1006 Riga, Latvia..
    Lindström, Mikael E.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sevastyanova, Olena
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    The Impact of Lignin Structural Diversity on Performance of Cellulose Nanofiber (CNF)-Starch Composite Films2019In: Polymers, E-ISSN 2073-4360, Vol. 11, no 3, article id 538Article in journal (Refereed)
    Abstract [en]

    Lignin fractions having different molecular weights and varied chemical structures isolated from kraft lignins of both softwood and hardwood via a sequential solvent fractionation technique were incorporated into a tunicate cellulose nanofibers (CNF)-starch mixture to prepare 100% bio-based composite films. The aim was to investigate the impact of lignin structural diversity on film performance. It was confirmed that lignin's distribution in the films was dependent on the polarity of solvents used for fractionation (acetone > methanol > ethanol > ethyl acetate) and influenced the optical properties of the films. The -OH group content and molecular weight of lignin were positively related to film density. In general, the addition of lignin fractions led to decrease in thermal stability and increase in Young's modulus of the composite films. The modulus of the films was found to decrease as the molecular weight of lignin increased, and a higher amount of carboxyl and phenolic -OH groups in the lignin fraction resulted in films with higher stiffness. The thermal analysis showed higher char content formation for lignin-containing films in a nitrogen atmosphere with increased molecular weight. In an oxygen atmosphere, the phenol content, saturated side chains and short chain structures of lignin had impacts on the maximum decomposition temperature of the films, confirming the relationship between the chemical structure of lignin and thermo-oxidative stability of the corresponding film. This study addresses the importance of lignin diversities on composite film performance, which could be helpful for tailoring lignin's applications in bio-based materials based on their specific characteristics.

  • 46.
    Zhao, Yadong
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. Zhejiang Ocean Univ, Sch Food & Pharm, Zhoushan 316022, Peoples R China.;Ocean TuniCell AS, POB 12, N-5868 Blomsterdalen, Norway..
    Troedsson, Christofer
    Ocean TuniCell AS, POB 12, N-5868 Blomsterdalen, Norway..
    Bouquet, Jean-Marie
    Ocean TuniCell AS, POB 12, N-5868 Blomsterdalen, Norway..
    Thompson, Eric M.
    Ocean TuniCell AS, POB 12, N-5868 Blomsterdalen, Norway.;Univ Bergen, Dept Biol Sci, N-5006 Bergen, Norway..
    Zheng, Bin
    Zhejiang Ocean Univ, Sch Food & Pharm, Zhoushan 316022, Peoples R China..
    Wang, Miao
    South China Univ Technol, Sch Chem & Chem Engn, Guangzhou 510640, Peoples R China..
    Mechanically Reinforced, Flexible, Hydrophobic and UV Impermeable Starch-Cellulose Nanofibers (CNF)-Lignin Composites with Good Barrier and Thermal Properties2021In: Polymers, E-ISSN 2073-4360, Vol. 13, no 24, p. 4346-, article id 4346Article in journal (Refereed)
    Abstract [en]

    Bio-based composite films have been widely studied as potential substitutes for conventional plastics in food packaging. The aim of this study was to develop multifunctional composite films by introducing cellulose nanofibers (CNF) and lignin into starch-based films. Instead of costly and complicated chemical modification or covalent coupling, this study optimized the performance of the composite films by simply tuning the formulation. We found that starch films were mechanically reinforced by CNF, with lignin dispersing as nanoparticles embedded in the matrix. The newly built-up hydrogen bonding between these three components improves the integration of the films, while the introduction of CNF and lignin improved the thermal stability of the starch-based films. Lignin, as a functional additive, improved hydrophobicity and blocked UV transmission. The inherent barrier property of CNF and the dense starch matrix provided the composite films with good gas barrier properties. The prepared flexible films were optically transparent, and exhibited UV blocking ability, good oxygen-barrier properties, high hydrophobicity, appreciable mechanical strength and good thermal stability. These characteristics indicate potential utilization as a green alternative to synthetic plastics especially for food packaging applications.

1 - 46 of 46
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf