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  • 1.
    Abbadessa, Anna
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Univ Santiago de Compostela, IDIS Res Inst, Ctr Res Mol Med & Chron Dis CIMUS, Campus Vida,Ave Barcelona S-N, Santiago De Compostela 15706, Spain.;Univ Santiago de Compostela, Sch Pharm, Dept Pharmacol Pharm & Pharmaceut Technol, Campus Vida,Ave Barcelona S-N, Santiago De Compostela 15706, Spain..
    Dogaris, Ioannis
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Farahani, Saina Kishani
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Reid, Michael S.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. RISE Res Inst Sweden, Dept Mat & Surface Design, Drottning Kristinas Vag 61, SE-11428 Stockholm, Sweden..
    Rautkoski, Hille
    VTT Tech Res Ctr Finland Ltd, POB 1000, FI-02044 Espoo, Finland..
    Holopainen-Mantila, Ulla
    VTT Tech Res Ctr Finland Ltd, POB 1000, FI-02044 Espoo, Finland..
    Oinonen, Petri
    Ecohelix AB, Teknikringen 38, S-10044 Stockholm, Sweden..
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Layer-by-layer assembly of sustainable lignin-based coatings for food packaging applications2023Ingår i: Progress in organic coatings, ISSN 0300-9440, E-ISSN 1873-331X, Vol. 182, artikel-id 107676Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Packaging plays a critical role in ensuring food safety and shelf life by protecting against e.g., moisture, gases, and light. Polyethylene (PE) is widely used in food packaging, but it is mainly produced from non-renewable resources and it is an inefficient oxygen and light barrier. In this study, the layer-by-layer (LbL) assembly of a sustainably produced lignin-based polymer (EH) with polyethylenimine (PEI) or chitosan (CH) was used to fabricate (partially or fully) bio-based coatings with the aim of improving barrier properties of PE films. The charge density of EH was calculated using a polyelectrolyte titration method and the hydrodynamic diameters of EH, PEI and CH were determined by Dynamic Light Scattering (DLS). LbL assembly was monitored in situ via Quartz Crystal Microbalance with Dissipation (QCM-D) and Stagnation Point Adsorption Reflectometry (SPAR). PE films were coated with a variable number of PEI/EH or CH/EH bilayers (BL) using an immersive LbL assembly method. Coated films were studied in terms of light-blocking ability, wettability, thermal behaviour, surface structure, as well as oxygen and water vapor barrier properties. QCM-D and SPAR data showed a stepwise multilayer formation and strong interactions between the oppositely charged polymers, with PEI/EH coating having a greater amount of deposited polymer compared to CH/EH coating at the same number of BL. Overall, light barrier properties and wettability of the coated films increased with the number of deposited bilayers. Coated PE films maintained the overall thermal behaviour of PE. A number of BL of 20 was found to be the most promising based on the studied properties. Selected samples showed improved oxygen and water vapor barrier properties, with PEI/EH coating performing better than CH/EH coating. Taken altogether, we demonstrated that a novel and sustainable lignin-based polymer can be combined with PEI or CH to fabricate (partially or fully) bio-based coatings for food packaging.

  • 2.
    Abbadessa, Anna
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Oinonen, Petri
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Ecohelix AB, Teknikringen 38, SE-10044 Stockholm, Sweden..
    Henriksson, Gunnar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Characterization of Two Novel Bio-based Materials from Pulping Process Side Streams: Ecohelix and CleanFlow Black Lignin2018Ingår i: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 13, nr 4, s. 7606-7627Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The characteristics of two novel types of technical lignin, namely Ecohelix (EH) and CleanFlow black lignin (CFBL), isolated from two different pulping process side streams, were analyzed. EH and CFBL were analyzed in terms of general composition, chemical functionalities, molar mass distribution, and thermal stability. For comparison, two relevant types of commercially available lignosulfonate and kraft lignin were used. The results showed that EH contains a large amount of sulfonated lignin, together with carbohydrates and ash. As such, it can be considered a lignin-carbohydrate hybrid molecule. CFBL was found to contain 91.5% Klason lignin and the lowest amount of carbohydrates (0.3%). EH showed the highest content of aliphatic OH groups (5.44 mmol/g) and CFBL a high content of phenols (4.73 mmol/g). EH had a molecular weight of 31.4 kDa and a sufficient thermal stability. CFBL had the lowest molecular weight (M-w = 2.0 kDa) and thermal stability of all kraft lignins analyzed in this study. These properties highlighted that EH is a suitable building block for material development and that CFBL is a promising material for the production of biofuel and biochemicals.

  • 3.
    Abbasi Aval, Negar
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Utilizing Biopolymers in 3D Tumor Modeling and Tumor Diagnosis2023Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Cancer utgör en betydande global utmaning inom folkhälsan och rankas som den nästvanligaste dödsorsaken i USA. Cancer börjar med en initial fas där celler förlorar sin polaritetoch lossnar från basalmembranet, vilket tillåter dem att bilda distinkta tredimensionella (3D)kluster som interagerar med intilliggande celler och den omgivande mikromiljön. Celler somodlas i 2D-monolager visar olika genuttryck och olika signalvägar jämfört med celler somodlas som mer naturlig 3D struktur likt tumörvävnad. Multicellulära tumörsfärer (MCTS) ärväl studerade som modell för organotypisk cancer, dessa sfärer bildas av tumörceller,antingen av samma typ eller i kombination med andra celltyper, och de kan skapas medeller utan användning av underliggande stödjande strukturer. MCTS betraktas även somlovande modell för preklinisk bedömning av cellernas kemokänslighet. Dock är skapandetav dessa tumörsfärer utmanande, eftersom alla tumörcellinjer inte verkar kunna bildaregelbundna sfärer.Cellulosananofibriller (CNF) är ett alternativ som hållbart och miljövänligt material. Sombland annat kan forma till tunna filmer, med inbyggda mekaniska egenskaper, flexibilitet ,erbjuder mångsidighet över olika tillämpningsområden, till följd av dess flexibilitet och dessinbyggda mekaniska egenskaper. Känd för sin biokompatibilitet och ofarliga natur fungerarCNF som ett bra alternativ för användning även inom biomedicinska tillämpningar. CNFstrukturen liknar kollagenmatrisen i mänsklig vävnad och visar potential som ett effektivtunderlag för 3D-cellodling. Inom detta område undersöktes en innovativ lager-på-lager (LbL)beläggningsmetod innehållande CNF och polyelektrolyt bilager för att skapa sfärer. Metodbygger bilager av CNF och polyelektrolyter som kan belägga ytor av olika material. Dennaavhandling fokuseradar först på att demonstrera sfärformationsförmågan vid användning avpolyelektrolyter med lågmolekylvikt i de tillverkade LbL-modifieringarna. Däreftergenomfördes en undersökning som innefattar inbäddning av sfärerna som bildades pådessa LbL-ytor i extracellulärmatris (ECM) dels i form av collagen samt decellulariseradextracellulärmatris. För att undersöka om ECMs mekaniska egenskaper kan påverkacancercellernas egenskaper i sfärerna samt om EMC med liknande mekaniska egenskaperlikt naturlig vävnad är lämplig. Därefter demonstrerar avhandlingen användningen av LbLför att fånga cirkulerande tumörceller som sedan kunde släppas i en liten volym. Till sistutforskades övergången från användning av polyelektrolyter med låg molekylvikt vid LbLuppbyggnadentill samma typ av polyelektrolyter men med högre molekylvikt, samtanalysera skillnaderna i möjligheten att bilda sfärer. Sammantaget har användningen avCNF-baserad LbL-ytbeläggningsstrategi som utforskats i avhandlingen visat sig varalovande för utvecklingen av multicellulära sfäroidmodeller och som kan ha en betydandepotential för tillämpningar inom läkemedelsutveckling.

  • 4.
    Abbasi Aval, Negar
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. Isfahan Univ Technol, Dept Mat Engn, Biomat Res Grp, Esfahan 8475683777, Iran.;Isfahan Univ Med Sci, Sch Med, Dept Anat Sci, Esfahan, Iran..
    Emadi, Rahmatollah
    Isfahan Univ Technol, Dept Mat Engn, Biomat Res Grp, Esfahan 8475683777, Iran..
    Valiani, Ali
    Isfahan Univ Med Sci, Sch Med, Dept Anat Sci, Esfahan, Iran..
    Kharaziha, Mahshid
    Isfahan Univ Technol, Dept Mat Engn, Biomat Res Grp, Esfahan 8475683777, Iran..
    Finne Wistrand, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    An aligned fibrous and thermosensitive hyaluronic acid-puramatrix interpenetrating polymer network hydrogel with mechanical properties adjusted for neural tissue2022Ingår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 57, nr 4, s. 2883-2896Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Central nervous system (CNS) injuries such as stroke or trauma can lead to long-lasting disability, and there is no currently accepted treatment to regenerate functional CNS tissue after injury. Hydrogels can mimic the neural extracellular matrix by providing a suitable 3D structure and mechanical properties and have shown great promise in CNS tissue regeneration. Here we present successful synthesis of a thermosensitive hyaluronic acid-RADA 16 (Puramatrix (TM)) peptide interpenetrating network (IPN) that can be applied in situ by injection. Thermosensitive hyaluronic acid (HA) was first synthesized by combining HA with poly(N-isopropylacrylamide). Then, the Puramatrix (TM) self-assembled peptide was combined with the thermosensitive HA to produce a series of injectable thermoresponsive IPNs. The HA-Puramatrix (TM) IPNs formed hydrogels successfully at physiological temperature. Characterization by SEM, rheological measurements, enzymatic degradation and swelling tests was performed to select the IPN optimized for neurologic use. SEM images of the optimized dry IPNs demonstrated an aligned porous structure, and the rheological measurements showed that the hydrogels were elastic, with an elastic modulus of approximately 500 Pa, similar to that of brain tissue. An evaluation of the cell-material interactions also showed that the IPN had biological characteristics required for tissue engineering, strongly suggesting that the IPN hydrogel possessed properties beneficial for regeneration of brain tissue.

  • 5.
    Abbasi Aval, Negar
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Khati, Vamakshi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Russom, Aman
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi.
    Layer-by-Layer cellulose nanofibril coating for spheroid formation combined with decellularized extracellular matrix for 3D tumor modelingManuskript (preprint) (Övrigt vetenskapligt)
  • 6.
    Abbasi Aval, Negar
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Khati, Vamakshi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi.
    Russom, Aman
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Influence of Decellularized Extra Cellular Matrix on 3D spheroids formed on Layer-by-Layer cellulose nanofibril/Polyelectrolytes coating as an in-vitro model for Hepatocellular CarcinomaManuskript (preprint) (Övrigt vetenskapligt)
  • 7.
    Abbasi Aval, Negar
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Lahchaichi, Ekeram
    Fayazbakhsh, Farzaneh
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi.
    Tudoran, Oana
    Russom, Aman
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Evaluating the Impact of Positively Charged Polyelectrolyte Molecular Weightand Bilayer Number on Tumor Spheroid Formation in the Interaction with Negatively Charged Cellulose Nanofibrils in layer by layer assembly2023Manuskript (preprint) (Övrigt vetenskapligt)
  • 8.
    Abbasi Aval, Negar
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Lahchaichi, Ekeram
    KTH, Centra, Science for Life Laboratory, SciLifeLab. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi.
    Tudoran, Oana
    Department of Genetics, Genomics and Experimental Pathology, The Oncology Institute “Prof. Dr. I. Chiricuta”, 400015 Cluj-Napoca, Romania.
    Fayazbakhsh, Farzaneh
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Heuchel, Rainer
    Pancreas Cancer Research Lab, Department of Clinical Science, Intervention and Technology, (CLINTEC), Karolinska Institutet, 17177 Stockholm, Sweden.
    Löhr, Matthias
    Pancreas Cancer Research Lab, Department of Clinical Science, Intervention and Technology, (CLINTEC), Karolinska Institutet, 17177 Stockholm, Sweden.
    Pettersson, Torbjörn
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Russom, Aman
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Proteinvetenskap, Nanobioteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Assessing the Layer-by-Layer Assembly of Cellulose Nanofibrils and Polyelectrolytes in Pancreatic Tumor Spheroid Formation2023Ingår i: Biomedicines, E-ISSN 2227-9059, Vol. 11, nr 11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Three-dimensional (3D) tumor spheroids are regarded as promising models for utilization as preclinical assessments of chemo-sensitivity. However, the creation of these tumor spheroids presents challenges, given that not all tumor cell lines are able to form consistent and regular spheroids. In this context, we have developed a novel layer-by-layer coating of cellulose nanofibril–polyelectrolyte bilayers for the generation of spheroids. This technique builds bilayers of cellulose nanofibrils and polyelectrolytes and is used here to coat two distinct 96-well plate types: nontreated/non-sterilized and Nunclon Delta. In this work, we optimized the protocol aimed at generating and characterizing spheroids on difficult-to-grow pancreatic tumor cell lines. Here, diverse parameters were explored, encompassing the bilayer count (five and ten) and multiple cell-seeding concentrations (10, 100, 200, 500, and 1000 cells per well), using four pancreatic tumor cell lines—KPCT, PANC-1, MiaPaCa-2, and CFPAC-I. The evaluation includes the quantification (number of spheroids, size, and morphology) and proliferation of the produced spheroids, as well as an assessment of their viability. Notably, our findings reveal a significant influence from both the number of bilayers and the plate type used on the successful formation of spheroids. The novel and simple layer-by-layer-based coating method has the potential to offer the large-scale production of spheroids across a spectrum of tumor cell lines.

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  • 9.
    Abbasi-Ravasjani, Sonia
    et al.
    Univ Amsterdam, Acad Ctr Dent Amsterdam ACTA, Dept Oral Cell Biol, Amsterdam Movement Sci, Amsterdam, Netherlands.;Vrije Univ Amsterdam, Amsterdam, Netherlands..
    Seddiqi, Hadi
    Univ Amsterdam, Acad Ctr Dent Amsterdam ACTA, Dept Oral Cell Biol, Amsterdam Movement Sci, Amsterdam, Netherlands.;Vrije Univ Amsterdam, Amsterdam, Netherlands..
    Moghaddaszadeh, Ali
    Islamic Azad Univ, Dept Biomed Engn, Sci & Res Branch, Tehran, Iran..
    Ghiasvand, Mohammad-Ehsan
    Amirkabir Univ Technol, Dept Mech Engn, Tehran, Iran..
    Jin, Jianfeng
    Univ Amsterdam, Acad Ctr Dent Amsterdam ACTA, Dept Oral Cell Biol, Amsterdam Movement Sci, Amsterdam, Netherlands.;Vrije Univ Amsterdam, Amsterdam, Netherlands..
    Oliaei, Erfan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer.
    Bacabac, Rommel Gaud
    Univ San Carlos, Dept Phys, Med Biophys Grp, Cebu, Philippines..
    Klein-Nulend, Jenneke
    Univ Amsterdam, Acad Ctr Dent Amsterdam ACTA, Dept Oral Cell Biol, Amsterdam Movement Sci, Amsterdam, Netherlands.;Vrije Univ Amsterdam, Amsterdam, Netherlands..
    Sulfated carboxymethyl cellulose and carboxymethyl kappa-carrageenan immobilization on 3D-printed poly-epsilon-caprolactone scaffolds differentially promote pre-osteoblast proliferation and osteogenic activity2022Ingår i: Frontiers in Bioengineering and Biotechnology, E-ISSN 2296-4185, Vol. 10, artikel-id 957263Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The lack of bioactivity in three-dimensional (3D)-printing of poly-epsilon-caprolactone (PCL) scaffolds limits cell-material interactions in bone tissue engineering. This constraint can be overcome by surface-functionalization using glycosaminoglycan-like anionic polysaccharides, e.g., carboxymethyl cellulose (CMC), a plant-based carboxymethylated, unsulfated polysaccharide, and kappa-carrageenan, a seaweed-derived sulfated, non-carboxymethylated polysaccharide. The sulfation of CMC and carboxymethylation of kappa-carrageenan critically improve their bioactivity. However, whether sulfated carboxymethyl cellulose (SCMC) and carboxymethyl kappa-carrageenan (CM-kappa-Car) affect the osteogenic differentiation potential of pre-osteoblasts on 3D-scaffolds is still unknown. Here, we aimed to assess the effects of surface-functionalization by SCMC or CM-kappa-Car on the physicochemical and mechanical properties of 3D-printed PCL scaffolds, as well as the osteogenic response of pre-osteoblasts. MC3T3-E1 pre-osteoblasts were seeded on 3D-printed PCL scaffolds that were functionalized by CM-kappa-Car (PCL/CM-kappa-Car) or SCMC (PCL/SCMC), cultured up to 28 days. The scaffolds' physicochemical and mechanical properties and pre-osteoblast function were assessed experimentally and by finite element (FE) modeling. We found that the surface-functionalization by SCMC and CM-kappa-Car did not change the scaffold geometry and structure but decreased the elastic modulus. Furthermore, the scaffold surface roughness and hardness increased and the scaffold became more hydrophilic. The FE modeling results implied resilience up to 2% compression strain, which was below the yield stress for all scaffolds. Surface-functionalization by SCMC decreased Runx2 and Dmp1 expression, while surface-functionalization by CM-kappa-Car increased Cox2 expression at day 1. Surface-functionalization by SCMC most strongly enhanced pre-osteoblast proliferation and collagen production, while CM-kappa-Car most significantly increased alkaline phosphatase activity and mineralization after 28 days. In conclusion, surface-functionalization by SCMC or CM-kappa-Car of 3D-printed PCL-scaffolds enhanced pre-osteoblast proliferation and osteogenic activity, likely due to increased surface roughness and hydrophilicity. Surface-functionalization by SCMC most strongly enhanced cell proliferation, while CM-kappa-Car most significantly promoted osteogenic activity, suggesting that surface-functionalization by CM-kappa-Car may be more promising, especially in the short-term, for in vivo bone formation.

  • 10.
    Abdelhamid, Hani Nasser
    et al.
    Stockholm Univ, Div Mat & Environm Chem, Svante Arrhenius Väg 16 C, SE-10691 Stockholm, Sweden.;Assiut Univ, Fac Sci, Dept Chem, Adv Multifunct Mat Lab, Assiut 71515, Egypt..
    Georgouvelas, Dimitrios
    Stockholm Univ, Div Mat & Environm Chem, Svante Arrhenius Väg 16 C, SE-10691 Stockholm, Sweden..
    Edlund, Ulrica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Mathew, Aji P.
    Stockholm Univ, Div Mat & Environm Chem, Svante Arrhenius Väg 16 C, SE-10691 Stockholm, Sweden..
    CelloZIFPaper: Cellulose-ZIF hybrid paper for heavy metal removal and electrochemical sensing2022Ingår i: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 446, artikel-id 136614Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The processing of hierarchical porous zeolitic imidazolate frameworks (ZIF-8) into a cellulose paper using sheet former Rapid-Kothen (R.K.) is reported. The procedure is a promising route to overcome a significant bottleneck towards applying metal-organic frameworks (MOFs) in commercial products. ZIF-8 crystals were integrated into cellulose pulp (CP) or TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-oxidized cellulose nanofibrils (TOCNF) following an in-situ or ex-situ process; the materials were denoted as CelloZIFPaper_In Situ and CelloZIFPaper_Ex Situ, respectively. The materials were applied as adsorbents to remove heavy metals from water, with adsorption capacities of 66.2-354.0 mg/g. CelloZIFPaper can also be used as a stand-alone working electrode for the selective sensing of toxic heavy metals, for instance, lead ions (Pb2+), using electrochemical-based methods with a limit of detection (LOD) of 8 mu M. The electrochemical measurements may advance 'Lab-onCelloZIFPaper' technologies for label-free detection of heavy metal ions.

  • 11.
    Adolfsson, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Carbon flake coated cellulose filters as dual function devices for rapid environmental contaminant detectionManuskript (preprint) (Övrigt vetenskapligt)
  • 12.
    Adolfsson, Karin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hydrothermal recycling of natural and synthetic polymers to functional carbon materials2019Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Utilizing renewable recourses and waste recycling are necessary for reaching a circular resource society. The concept of this thesis was to set up a sustainable recycling route, suitable even for low quality biopolymer and plastic waste for production of functional carbon materials. Carbonaceous materials were prepared by mild hydrothermal carbonizations of cellulose and polypropylene (PP) under acidic conditions. The carbonization of cellulose resulted mainly in micro-/nanometer sized carbon spheres (CS) with polar functionalities. After carbonization of PP, products were found in solid and liquid phase. Completely carbonized solid carbons products were obtained from PP at 250 °C after 60 min. The liquid products from the same process displayed aromatics and exhibited fluorescence properties. In addition, new carbon materials were prepared by acid, base and thermal treatments of the carbonized products at low temperatures. Thermally resistant carbon products and antibacterial CS towards both Staphylococcus aureus and Pseudomonas aeruginosa were demonstrated as possible applications for these products. The minimum inhibitory concentrations of CS were 200-400 µg mL-1 depending on the bacteria strain and reached after only 3 h. Furthermore, nanometer sized carbon nanodots with high oxygenation degree and fluorescence properties were derived together with carbon flakes (CF) from the carbonized products. The CF with flat and micrometer sized morphology and polar groups were utilized for coating of cationized cellulose filters, applied as adsorbents and then subsequently as surfaces for SALDI-MS analysis of environmental contaminants. This work contributes with new routes to and applications for functional carbon materials.

  • 13.
    Adolfsson, Karin H.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Golda-Cepa, M
    Benyahia Erdal, Nejla
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Duch, J
    Kotarba, A
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Importance of Surface Functionalities for Antibacterial Properties of Carbon Spheres2019Ingår i: Advanced Sustainable Systems, ISSN 2366-7486Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Carbon spheres (CS) are interesting materials for antibacterial applications. Herein, CS are produced by a green process utilizing microwave-assisted hydrothermal treatment of cellulose. The CS are then postmodified in acidic and basic solutions to evaluate the influence of different functionalities on antibacterial properties. CS contain OH/COOH, C Symbol of the Klingon Empire C, and C Symbol of the Klingon Empire O functionalities, while O-CS produced by acid treatment of CS have additional COOH, and NH/NH2 groups, resulting in carbon spheres with negatively and positively charged groups in dispersion. Treatment with base (Na-CS) removes low molecular weight species with oxygen and results in carbon spheres with the highest C/O ratio. CS, O-CS, and Na-CS have nonporous morphology and are in micro/nanometer sizes, although, smaller sized spheres, hollow spheres, and fragments are also attained in the case of O-CS. O-CS show antibacterial activity toward both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Pseudomonas aeruginosa (P. aeruginosa). The minimum inhibitory concentration is 200 and 400 mu g mL(-1) for S. aureus and P. aeruginosa, respectively, and is achieved only after 3 h of incubation. Neither CS nor Na-CS exhibit antibacterial activity. The antibacterial activity is suggested to originate from electrostatic interactions between O-CS and the bacteria.

  • 14.
    Adolfsson, Karin H.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Huang, Ping
    Department of Chemistry – Ångström Laboratory, Uppsala University, Box 523, Uppsala, 751 20, Sweden, Box 523.
    Golda-Cepa, Monika
    Faculty of Chemistry, Jagiellonian Universityul, Krakow, 30–387, Poland.
    Xu, Huan
    School of Materials Science and Physics, China University of Mining and Technology, Xuzhou, 221116, P. R. China.
    Kotarba, Andrzej
    Faculty of Chemistry, Jagiellonian Universityul, Krakow, 30–387, Poland.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Scavenging of DPPH by Persistent Free Radicals in Carbonized Particles2023Ingår i: Advanced Sustainable Systems, E-ISSN 2366-7486, Vol. 7, nr 3, artikel-id 2200425Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Persistent free radicals (PFR) in carbonized particles may play a role in degradation of environmental compounds. The influence of PFR is evaluated in various carbonized particles on their radical scavenging efficiency upon the common radical indicator 2-2-diphenyl-1-picrylhydrazyl (DPPH). Carbonized particles are derived by hydrothermal carbonization of glucose (C-W) or glucose and urea (NC-W) and ionothermal carbonization of glucose and urea ionic liquid (IL) (NC-IL). The carbonized materials contain OH/COOH, C=C, and C-O functionalities. The addition of urea introduces NH/NH2 functionalities. The content of polar surface groups is lower in IL-processed NC-IL. The scavenging ability, measured as DPPH UV–vis absorption decline, increases with concentration and time for all particles, while the efficiency changes are in the order of C-W > NC-W > NC-IL. Electron paramagnetic resonance analysis reveals similar radical concentration in all carbonized materials studied. The difference in efficiency is, thus, not directly related to the PFR concentration but rather to the type of PFR, surface functionalities and/or scavenging mechanism. According to the g-values, radicals in these particles are carbon-centered. The minor variation in g-values suggests interactions between the radicals and their environmental functional groups. This provides insights into the influence of PFR in carbonized materials on their radical scavenging efficiency.

  • 15.
    Adolfsson, Karin H.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lin, Chia-feng
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Microwave Assisted Hydrothermal Carbonization and Solid State Postmodification of Carbonized Polypropylene2018Ingår i: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 6, nr 8, s. 11105-11114Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Functional carbon materials produced through a hydrothermal treatment of waste products have gained interest. Particularly, the method is considered more facile and green compared to conventional decomposition methods. Here, we demonstrated an upcycling of polypropylene (PP) waste to carbon materials by a microwave assisted hydro thermal treatment. The solid product obtained from the hydrothermal treatment was analyzed by multiple techniques to reveal the structure and the influence of processing conditions on PP degradation and hydrothermal carbonization. Chemical analyses showed the presence of carbonaceous material independent of acid amount (20 and 30 mL), temperature (210 and 250 degrees C), and time (20-80 min). A complete transformation of PP content to amorphous carbon required 60 min at 250 degrees C. The mass yield of the solid product decreased as a function of harsher processing conditions. At the same time, thermogravimetric analysis illustrated products with increasing thermal stability and a larger amount of remaining residue at 600 degrees C. The solid products consisted of irregular fragments and sheet-like structures. A solid state microwave process in air atmosphere was performed on a product with incomplete carbonization. The modification resulted in a decreased C/O ratio, and TGA analysis in nitrogen showed high thermal stability and degree of carbonization as indicated by the remaining residue of 86.4% at 600 degrees C. The new insights provided on the hydrothermal carbonization, and postmodification in air atmosphere, can catalyze effective handling of plastic waste by enabling transformation of low quality waste into functional carbon materials.

  • 16.
    Adolfsson, Karin H.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Melilli, Giuseppe
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Oxidized Carbonized Cellulose-Coated Filters for Environmental Contaminant Adsorption and Detection2020Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 59, nr 30, s. 13578-13587Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cationized cellulose filters with coating of oxidized carbonized cellulose (OCC) were successfully fabricated. The OCC-coated filter was demonstrated as a combined surface for adsorption of environmental contaminants and their detection on the filter by surface-assisted desorption ionization-mass spectrometry (SALDI-MS). The cellulose filters were cationized by utilizing 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHTAC) and sodium hydroxide. It was shown that the degree of substitution increased with the CHTAC feed. OCC, synthesized by hydrothermal carbonization of cellulose with subsequent oxidation and dialysis, was attached onto the cationized filters by electrostatic interactions. The filters adsorbed the model contaminant methylene blue (MB) from aqueous solution, and the MB could subsequently be detected on the filter surfaces by SALDI-MS as [M](+) adduct. The OCC coating further improved the relative peak intensity of [M](+) with little background interferences. This work indicates great potential for the OCC-coated filters as a combined surface for rapid monitoring of environmental contaminants.

  • 17.
    Adolfsson, Karin H.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Sjöberg, I.
    Höglund, O. V.
    Wattle, O.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    In Vivo Versus In Vitro Degradation of a 3D Printed Resorbable Device for Ligation of Vascular Tissue in Horses2021Ingår i: Macromolecular Bioscience, ISSN 1616-5187, E-ISSN 1616-5195, Vol. 21, nr 10, artikel-id 2100164Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A resorbable 3D printed polydioxanone (PDO) device is manufactured to facilitate ligation of vascular tissue during surgery. The device must provide sufficient mechanical performance throughout the healing period. Therefore, degradation and mechanical performance of the device are investigated as a function of in vivo and in vitro aging. During aging the PDO device released cyclic and linear water-soluble products. In vivo aging resulted in higher relative number of linear oligomers in comparison to in vitro aging. A major loss of mechanical performance is observed after only 10 days in vivo and the Young’s modulus (E) and tensile strength at break (σb) decreased by 28% and 54%, respectively. This is in contrast to in vitro aging, where no loss of mechanical properties is observed during the same period. The in vivo aged devices exhibit clear holes in the matrices after 28 days, while apparent cracks are observed first after 140 days in vitro. These results highlight the sensitivity of the degradation process of resorbable devices with regards to the interactions of the device with the surrounding environment (tissues) and demonstrate the importance of in vivo testing as compliment to in vitro testing before clinical use of devices.

  • 18.
    Adolfsson, Karin
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Yadav, Nisha
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Hakkarainen, Minna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Cellulose-derived hydrothermally carbonized materials and their emerging applications2020Ingår i: Current Opinion in Green and Sustainable Chemistry, E-ISSN 2452-2236 , Vol. 23, s. 18-24Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hydrothermally carbonized cellulose and its further modifications are intriguing materials for a wide range of potential applications. Hydrothermal carbonization is a sustainable process for converting biopolymers or other biomass sources into carbonaceous materials under mild conditions in water and at relatively low temperatures. This review presents the latest progress in modification and utilization of hydrothermally carbonized cellulose and related materials in environmental, biomedical, and energy applications. Further applications presented include evaluation of cellulose-derived carbon spheres or carbon dots as catalysts, antibacterial materials, flame retardants, and functional fillers in bioplastic composites. The wide range of applications highlights the great potential and multifunctionality of hydrothermally carbonized cellulose and its derivatives. The field is expected to further expand and increase in importance as we move toward circular bioeconomy.

  • 19.
    Afewerki, Samson
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Edlund, Ulrica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Combined Catalysis: A Powerful Strategy for Engineering Multifunctional Sustainable Lignin-Based Materials2023Ingår i: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 17, nr 8, s. 7093-7108Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The production and engineering of sustainable materials through green chemistry will have a major role in our mission of transitioning to a more sustainable society. Here, combined catalysis, which is the integration of two or more catalytic cycles or activation modes, provides innovative chemical reactions and material properties efficiently, whereas the single catalytic cycle or activation mode alone fails in promoting a successful reaction. Polyphenolic lignin with its distinctive structural functions acts as an important template to create materials with versatile properties, such as being tough, antimicrobial, self-healing, adhesive, and environmentally adaptable. Sustainable lignin-based materials are generated by merging the catalytic cycle of the quinone-catechol redox reaction with free radical polymerization or oxidative decarboxylation reaction, which explores a wide range of metallic nanoparticles and metal ions as the catalysts. In this review, we present the recent work on engineering lignin-based multifunctional materials devised through combined catalysis. Despite the fruitful employment of this concept to material design and the fact that engineering has provided multifaceted materials able to solve a broad spectrum of challenges, we envision further exploration and expansion of this important concept in material science beyond the catalytic processes mentioned above. This could be accomplished by taking inspiration from organic synthesis where this concept has been successfully developed and implemented.

  • 20.
    Aguilar-Sanchez, Andrea
    et al.
    Stockholm Univ, Div Mat & Environm Chem, Frescativagen 8, S-10691 Stockholm, Sweden..
    Jalvo, Blanca
    Stockholm Univ, Div Mat & Environm Chem, Frescativagen 8, S-10691 Stockholm, Sweden..
    Mautner, Andreas
    Univ Vienna, Fac Chem, Inst Mat Chem & Res, Polymer & Composite Engn PaCE Grp, Wahringer Str 42, A-1090 Vienna, Austria..
    Nameer, Samer
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Pohler, Tiina
    VTT Tech Res Ctr Finland, Solut Nat Resources & Environm, POB 1000, FI-02044 Espoo, Finland..
    Tammelin, Tekla
    VTT Tech Res Ctr Finland, Solut Nat Resources & Environm, POB 1000, FI-02044 Espoo, Finland..
    Mathew, Aji P.
    Stockholm Univ, Div Mat & Environm Chem, Frescativagen 8, S-10691 Stockholm, Sweden..
    Waterborne nanocellulose coatings for improving the antifouling and antibacterial properties of polyethersulfone membranes2021Ingår i: Journal of Membrane Science, ISSN 0376-7388, E-ISSN 1873-3123, Vol. 620, artikel-id 118842Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This article presents a waterborne nanocellulose coating process to change the surface characteristics and mitigate fouling of commercially available polyethersulfone (PES) microfiltration membranes. An extensive comparative study between nanoporous and nano-textured layers composed of cellulose nanocrystals (CNC) or TEMPO-oxidized cellulose nanofibrils (T-CNF), which were coated on the PES membrane by taking advantage of the electrostatic interactions between the PES substrate, a polyallylamine hydrochloride (PAHC1) anchoring layer, and the nanocellulose functional layer. Coated PES membranes exhibited decreased surface roughness and pore sizes as well as rejection of compounds with a M-w above 150 kDa, while the water permeability and mechanical properties of remained largely unaffected. The coatings improved the wettability as confirmed by a reduction of the contact angle by up to 52% and exhibited a higher negative surface charge compared to the uncoated membranes over a pH range of 4-8. A significant reduction in organic fouling was observed for the coated membranes demonstrated by bovine serum albumin (BSA) adsorption studies on T-CNF and CNC surfaces using Quartz Crystal Microbalance with Dissipation monitoring (QCM-D), UV-vis spectroscopy and FTIR mapping after exposing the membranes to dynamic adsorption of BSA. The T-CNF coating exhibited effective antibacterial action against Escherichia coli (E. coli) attributed to the pH reduction effect induced by the carboxyl groups; while CNC coatings did not show this property. This work demonstrates a simple, green, and easy-to-scale layer-by-layer coating process to tune the membrane rejection and to improve antifouling and antibacterial properties of commercially available membranes.

  • 21.
    Agustin, Melissa B.
    et al.
    VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland, P.O. Box 1000; Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland, P.O. Box 66.
    Lahtinen, Maarit H.
    Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland, P.O. Box 66.
    Kemell, Marianna
    Department of Chemistry, Faculty of Science, University of Helsinki, P.O. Box 55, FI-00014, Helsinki, Finland, P.O. Box 55.
    Oliaei, Erfan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Mikkonen, Kirsi S.
    Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland, P.O. Box 66; Helsinki Institute of Sustainability Science, University of Helsinki, P.O. Box 65, FI-00014, Helsinki, Finland, P.O. Box 65.
    Grönqvist, Stina
    VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT, Finland, P.O. Box 1000.
    Lehtonen, Mari
    Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland, P.O. Box 66.
    Enzymatic crosslinking of lignin nanoparticles and nanocellulose in cryogels improves adsorption of pharmaceutical pollutants2024Ingår i: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 266, artikel-id 131168Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pharmaceuticals, designed for treating diseases, ironically endanger humans and aquatic ecosystems as pollutants. Adsorption-based wastewater treatment could address this problem, however, creating efficient adsorbents remains a challenge. Recent efforts have shifted towards sustainable bio-based adsorbents. Here, cryogels from lignin-containing cellulose nanofibrils (LCNF) and lignin nanoparticles (LNPs) were explored as pharmaceuticals adsorbents. An enzyme-based approach using laccase was used for crosslinking instead of fossil-based chemical modification. The impact of laccase treatment on LNPs alone produced surface-crosslinked water-insoluble LNPs with preserved morphology and a hemicellulose-rich, water-soluble LNP fraction. The water-insoluble LNPs displayed a significant increase in adsorption capacity, up to 140 % and 400 % for neutral and cationic drugs, respectively. The crosslinked cryogel prepared by one-pot incubation of LNPs, LCNF and laccase showed significantly higher adsorption capacities for various pharmaceuticals in a multi-component system than pure LCNF or unmodified cryogels. The crosslinking minimized the leaching of LNPs in water, signifying enhanced binding between LNPs and LCNF. In real wastewater, the laccase-modified cryogel displayed 8–44 % removal for cationic pharmaceuticals. Overall, laccase treatment facilitated the production of bio-based adsorbents by improving the deposition of LNPs to LCNF. Finally, this work introduces a sustainable approach for engineering adsorbents, while aligning with global sustainability goals.

  • 22.
    Agustin, Melissa B.
    et al.
    Univ Helsinki, Fac Agr & Forestry, Dept Food & Nutr, POB 66, FI-00014 Helsinki, Finland..
    Lehtonen, Mari
    Univ Helsinki, Fac Agr & Forestry, Dept Food & Nutr, POB 66, FI-00014 Helsinki, Finland..
    Kemell, Marianna
    Univ Helsinki, Fac Sci, Dept Chem, POB 55, FI-00014 Helsinki, Finland..
    Lahtinen, Panu
    VTT Tech Res Ctr Finland, POB 1000, FIN-02044 Espoo, Finland..
    Oliaei, Erfan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Mikkonen, Kirsi S.
    Univ Helsinki, Fac Agr & Forestry, Dept Food & Nutr, POB 66, FI-00014 Helsinki, Finland.;Univ Helsinki, Helsinki Inst Sustainabil Sci, POB 65, FI-00014 Helsinki, Finland..
    Lignin nanoparticle-decorated nanocellulose cryogels as adsorbents for pharmaceutical pollutants2023Ingår i: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 330, artikel-id 117210Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Adsorption is a relatively simple wastewater treatment method that has the potential to mitigate the impacts of pharmaceutical pollution. This requires the development of reusable adsorbents that can simultaneously remove pharmaceuticals of varying chemical structure and properties. Here, the adsorption potential of nanostructured wood-based adsorbents towards different pharmaceuticals in a multi-component system was investigated. The adsorbents in the form of macroporous cryogels were prepared by anchoring lignin nanoparticles (LNPs) to the nanocellulose network via electrostatic attraction. The naturally anionic LNPs were anchored to cationic cellulose nanofibrils (cCNF) and the cationic LNPs (cLNPs) were combined with anionic TEMPO-oxidized CNF (TCNF), producing two sets of nanocellulose-based cryogels that also differed in their overall surface charge density. The cryogels, prepared by freeze-drying, showed layered cellulosic sheets randomly decorated with spherical lignin on the surface. They exhibited varying selectivity and efficiency in removing pharmaceuticals with differing aromaticity, polarity and ionic characters. Their adsorption potential was also affected by the type (unmodified or cationic), amount and morphology of the lignin nanomaterials, as well as the pH of the pharmaceutical solution. Overall, the findings revealed that LNPs or cLNPs can act as functionalizing and crosslinking agents to nanocellulose-based cryogels. Despite the decrease in the overall positive surface charge, the addition of LNPs to the cCNF-based cryogels showed enhanced adsorption, not only towards the anionic aromatic pharmaceutical diclofenac but also towards the aromatic cationic metoprolol (MPL) and tramadol (TRA) and neutral aromatic carbamazepine. The addition of cLNPs to TCNF-based cryogels improved the adsorption of MPL and TRA despite the decrease in the net negative surface charge. The improved adsorption was attributed to modes of removal other than electrostatic attraction, and they could be 7C-7C aromatic ring or hydrophobic interactions brought by the addition of LNPs or cLNPs. However, significant improvement was only found if the ratio of LNPs or cLNPs to nanocellulose was 0.6:1 or higher and with spherical lignin nanomaterials. As crosslinking agents, the LNPs or cLNPs affected the rheological behavior of the gels, and increased the firmness and decreased the water holding capacity of the corresponding cryogels. The resistance of the cryogels towards disintegration with exposure to water also improved with crosslinking, which eventually enabled the cryogels, especially the TCNF-based one, to be regenerated and reused for five cycles of adsorption-desorption experiment for the model pharmaceutical MPL. Thus, this study opened new opportunities to utilize LNPs in providing nanocellulose-based adsorbents with additional functional groups, which were otherwise often achieved by rigorous chemical modifications, at the same time, crosslinking the nanocellulose network.

  • 23.
    Agustin, Melissa B.
    et al.
    Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland; VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044, Espoo, Finland.
    Nematollahi, Neda
    Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland.
    Bhattarai, Mamata
    Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland; Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076, Aalto, Finland.
    Oliaei, Erfan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer.
    Lehtonen, Mari
    Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland.
    Rojas, Orlando J.
    Department of Bioproducts and Biosystems, Aalto University, P.O. Box 16300, 00076, Aalto, Finland; Bioproducts Institute, Department of Chemical and Biological Engineering, Department of Chemistry and Department of Wood Science, University of British Columbia, 2360, East Mall, Vancouver, BC, V6T 1Z3, Canada.
    Mikkonen, Kirsi S.
    Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014, Helsinki, Finland; Helsinki Institute of Sustainability Science, University of Helsinki, P.O. Box 65, FI-00014, Helsinki, Finland.
    Lignin nanoparticles as co-stabilizers and modifiers of nanocellulose-based Pickering emulsions and foams2023Ingår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 30, nr 14, s. 8955-8971Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nanocellulose is very hydrophilic, preventing interactions with the oil phase in Pickering emulsions. This limitation is herein addressed by incorporating lignin nanoparticles (LNPs) as co-stabilizers of nanocellulose-based Pickering emulsions. LNP addition decreases the oil droplet size and slows creaming at pH 5 and 8 and with increasing LNP content. Emulsification at pH 3 and LNP cationization lead to droplet flocculation and rapid creaming. LNP application for emulsification, prior or simultaneously with nanocellulose, favors stability given the improved interactions with the oil phase. The Pickering emulsions can be freeze–dried, enabling the recovery of a solid macroporous foam that can act as adsorbent for pharmaceutical pollutants. Overall, the properties of nanocellulose-based Pickering emulsions and foams can be tailored by LNP addition. This strategy offers a unique, green approach to stabilize biphasic systems using bio-based nanomaterials without tedious and costly modification procedures.

  • 24.
    Ahlinder, Astrid
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi. KTH Royal Institute of Technology.
    Degradable copolymers in additive manufacturing: controlled fabrication of pliable scaffolds2021Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Inom vävnadsregenerering är produktionen av väldefinieradematriser med en porös arkitektur av nedbrytbara polymerer av stortintresse, dessa kan nu skapas genom additiva tillverkningsprocesser. Vidadditiv tillverkning krävs ett smalt munstycke för att skapa detaljrikastrukturer och detta ställer krav på att de reologiska egenskapernaanpassat. Lägre viskositet av smältan gör de lättare att använda, men enhög molmassa krävs för tillverka matriser där de mekaniska egenskapernakan bibehållas under tiden som krävs för vävnadsregenerering. Ytterligareen utmaning uppstår när nedbrytbara polymerer används i smältbaseradadditiva tillverkningsprocesser är att termisk nedbrytning ofta reducerarmolmassan redan under produktionsfasen. För att kunna användanedbrytbara polymerer av medicinsk kvalitet i smältbaserad additivtillverkning och samtidigt minimera den termiska nedbrytningen har, idenna avhandling, reologiska fingeravtryck av nedbrytbara syntetiskapolymerer med medicinsk kvalitet använts för att bestämmaprocessparametrar. Termisk nedbrytning beroende av processparamaterar har analyserats och minimeras i två smältbaserade additivatillverkningsprocesser.En additiv tillverkningsprocess var designad där nedbrytbarapolymerer av hög molmassa kunde användas utan termisk nedbrytning närprocessparametrar hade valts utifrån polymerens egenskaper. Kunskapenom användningen av dessa polymerer inom additiv tillverkning kundeappliceras på en sampolymer som utvecklats inom forskningsgruppen förmjukvävnad, poly(ε-kaprolakton-co-p-dioxanon) för att skapa böjbaramatriser. Genom att använda reologisk analys och polymerkarakteriseringerhölls processparametrar som möjliggjorde additiv tillverkning utantermisk nedbrytning. I tillägg till val av polymer och processparametrar såkan mekaniska egenskaper också styras av den strukturella designen.Poly(ε-kaprolakton) användes som modellmaterial för att reducerastyvheten med hjälp av designen, resultatet visade att det var möjligt medmer än en faktor 10 och mjuka böjbara matriser skapades.

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  • 25.
    Ahlinder, Astrid
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Charlon, Sebastien
    IMT Lille Douai, Ecole nationale supérieure Mines-Télécom Lille Douai, Materials & Processes Center, Cité scientifique, Villeneuve d'Ascq Cedex, France.
    Fuoco, Tiziana
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Soulestin, Jeremie
    IMT Lille Douai, Ecole nationale supérieure Mines-Télécom Lille Douai, Materials & Processes Center, Cité scientifique, Villeneuve d'Ascq Cedex, France.
    Finne Wistrand, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Minimise thermo-mechanical batch variations when processing medical grade lactide based copolymers in additive manufacturing2020Ingår i: Polymer degradation and stability, ISSN 0141-3910, E-ISSN 1873-2321, Vol. 181, artikel-id 109372Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Additive manufacturing is suitable for producing complex geometries; however, variation in thermo-mechanical properties are observed during one batch cycle when degradable aliphatic polyesters of medical grade are used in melt extrusion-based methods. This is one important reason for why additive manufacturing has not yet been fully utilised to produce degradable medical implants. Herein, the internal variation has been minimised during one batch cycle by assessing the effect of different processing parameters when using commercially available medical grade copolymers. To minimise the molar mass, thermal and mechanical variation within one batch cycle, the rheological fingerprint of the commercially available medical grade poly(L-lactide-co-ε-caprolactone) and poly(L-lactide-co-trimethylene carbonate) has been correlated to the process parameters of the ARBURG Plastic Freeforming. An increase in the temperature up to 220°C and the associated increase in pressure are beneficial for the viscoelastic and thermally stable poly(L-lactide-co-ε-caprolactone). In contrast, a temperature below 220°C should be used for the poly(L-lactide-co-trimethylene carbonate) to reduce the variation in strain at break during one batch cycle. The residence time is decreased through the increase of the discharge parameter. An increase in temperature is however required to reduce the viscosity of the polymer and allow the pressure to stay within the machine limitations at higher discharge parameters. The results are highly relevant to the development of additive manufacturing for the production of degradable medical devices with identical properties. In fact, Food and Drug Administration guidelines for additive manufacturing of medical implants specify the need to control changes in material properties during the process.

  • 26.
    Ahlinder, Astrid
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Fuoco, Tiziana
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymerteknologi.
    Finne Wistrand, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Medical grade polylactide, copolyesters and polydioxanone: Rheological properties and melt stability2018Ingår i: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 72, s. 214-222Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rheological measurements have shown that lactide-based copolymers with L-lactide content between 50 and 100 mol% with varying comonomers, as well as polydioxanone (PDX), can be used in additive manufacturing analogously to poly(L-lactide) (PLLA) if their melt behaviour are balanced. The results indicate that copolymers can be melt processed if the temperature is adjusted according to the melting point, and parameters such as the speed are tuned to conteract the elastic response. Small amplitude oscillatory shear (SAOS) rheology, thermal and chemical characterisation allowed us to map the combined effect of temperature and frequency on the behaviour of six degradable polymers and their melt stability. Values of complex viscosity and Tan delta obtained through nine time sweeps by varying temperature and frequency showed that the molecular structure and the number of methylene units influenced the results, copolymers of L-lactide with D-Lactide (PDLLA) or glycolide (PLGA) had an increased elastic response, while copolymers with trimethylene carbonate (PLATMC) or epsilon-caprolactone (PCLA) had a more viscous behaviour than PLLA, with respect to their relative melting points. PDLLA and PLGA require an increased temperature or lower speed when processed, while PLATMC and PCLA can be used at a lower temperature and/or higher speed than PLLA. PDX showed an increased viscosity compared to PLLA but a similar melt behaviour. Negligible chain degradation were observed, apart from PLGA.

  • 27.
    Ahlinder, Astrid
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Fuoco, Tiziana
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Morales-Lopez, Alvaro
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Yassin, Mohammed A.
    Univ Bergen, Fac Med, Dept Clin Dent, Bergen, Norway..
    Mustafa, Kamal
    Univ Bergen, Fac Med, Dept Clin Dent, Bergen, Norway..
    Finne Wistrand, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Nondegradative additive manufacturing of medical grade copolyesters of high molecular weight and with varied elastic response2020Ingår i: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 137, nr 15, artikel-id 48550Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although additive manufacturing through melt extrusion has become increasingly popular as a route to design scaffolds with complex geometries the technique if often limited by the reduction in molecular weight and the viscoelastic response when degradable aliphatic polyesters of high molecular weight are used. Here we use a melt extruder and fused filament fabrication printer to produce a reliable nondegradative route for scaffold fabrication of medical grade copolymers of L-lactide, poly(epsilon-caprolactone-co-L-lactide), and poly(L-lactide-co-trimethylene carbonate). We show that degradation is avoided using filament extrusion and fused filament fabrication if the process parameters are deliberately chosen based upon the rheological behavior, mechanical properties, and polymer composition. Structural, mechanical, and thermal properties were assessed throughout the process to obtain comprehension of the relationship between the rheological properties and the behavior of the medical grade copolymers in the extruder and printer. Scaffolds with a controlled architecture were achieved using high-molecular-weight polyesters exhibiting a large range in the elastic response causing negligible degradation of the polymers.

  • 28.
    Ahlström, Leon
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Evaluation of Woodmer/plastic composites2023Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Plast ger otroliga möjligheter i form av stor variation för materialanvändning. Tyvärr sker det dock på bekostnad av miljön då de ackumuleras i naturen. En kompromiss mellan hållbarhet och fortsatt plastanvändning skulle kunna vara att använda biomassa som fyllnadsmaterial i plastkompositer istället för plast. Detta skulle i sin tur minska mängden plast och öka användningen av förnybara råvaror. Naturligtvis måste de mekaniska och termiska egenskaperna också vara av acceptabel kvalitet för materialtillämpningar och helst även erbjuda någon form av uppgradering av det redan existerande materialet. Ett potentiellt fyllnadsmaterial är Woodmer, en LCC (lignin kolhydrat komplex) som produceras av Ecohelix. Woodmers förmåga att agera som ett termoplastiskt kompositmaterial analyserades och jämfördes med de respektive jungfruliga termoplasterna. Tre olika plaster används som bas för kompositerna och dessa plaster var akrylnitril-butadien-styren (ABS), polymjölksyra (PLA) och lågdensitetspolyeten (LDPE).

    Resultaten visar att det är möjligt att skapa homogena Woodmer/termoplast kompositmaterial. När det gäller de termiska egenskaperna, så gav inte UL 94 någon brandklassificering på materialen, några positiva effekter observerades i TGA och resultaten från DSC var mestadels oförändrade jämfört med respektive jungfrulig plast. Dragprovning visade å andra sidan att de mekaniska egenskaperna påverkas negativt av högre Woodmer tillsatser men effekten varierade kraftigt mellan de olika plasterna då LDPE var minst påverkad och PLA mest påverkad. Framtida forskning bör fokusera på att tillverka material genom dubbelskruv extrudering eftersom det tyvärr fanns problem med blandningen i enkelskruv extrudering. Ytterligare forskning kring materialens morfologi, löslighet och så vidare krävs också för att se om kompositerna är lämpliga material eller om det finns några oförutsedda problem.

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  • 29.
    Ahlström, Leon
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Mattsson, Rebecca
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Eurén, Hampus
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lidén, Alicia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Spruce bark biorefinery2021Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Spruce Bark contains several fundamental main substances; lignin, non-cellulose polysaccharides, cellulose and extractives. This undergraduate study focuses on developing a process to extract each of these components from spruce bark using a biorefinery concept, with a main focus on extracting lignin without degradation. The purpose of the Bark biorefinery concept is to contribute to a circular bioeconomy, by making use of natural resources. With extended research on the area, it will be possible to produce polymers, green chemicals and biofuel from the components in bark. 

    This report covers the extraction of the bark components with soxhlet extraction, Hot-water extraction, organosolv extraction and peracetic acid delignification. The extraction was made on two samples, matchstick-sized bark (MS) and 20 mesh-sized bark with a diameter of 0.8 mm (20M). The purpose was to be able to compare the efficiency of the extraction between the two samples. Afterwards, the characterisation of extracts and residue was executed with carbohydrate analysis, 2D HSQC-NMR and FTIR-analysis. 

    The results showed that a smaller particle size led to more efficient extractions of all components as well as more pure extract solutions. Lignin concentration determinations of samples at each step showed that a significant amount of lignin was lost prior to the organosolv extraction. Future research should look into ways to reduce this loss in order to increase the lignin yield. The findings in the FTIR and NMR analyses correlates with what could be seen in other reports, discussing similar subjects. For upscaling of this process, future research should go toward optimization of all extraction methods in order to make an upscaling of the process economically viable.  

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  • 30. Ahmed, A.
    et al.
    Hassan, I.
    Pourrahimi, Amir Masoud
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi. Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Göteborg, 41296 Sweden.
    Helal, A. S.
    El-Kady, M. F.
    Khassaf, H.
    Kaner, R. B.
    Toward High-Performance Triboelectric Nanogenerators by Engineering Interfaces at the Nanoscale: Looking into the Future Research Roadmap2020Ingår i: Advanced Materials Technologies, E-ISSN 2365-709X, Vol. 5, nr 11, s. 2000520-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To meet the future need for clean and sustainable energies, there has been considerable interest in the development of triboelectric nanogenerators (TENGs) that scavenge waste mechanical energies. The performance of a TENG at the macroscale is determined by the multifaceted role of surface and interface properties at the nanoscale, whose understanding is critical for the future development of TENGs. Therefore, various protocols from the atomic to the macrolevel for fabrication and tuning of surfaces and interfaces are required to obtain the desired TENG performance. These protocols branch out into three categories: chemical engineering, physical engineering, and structural engineering. Chemical engineering is an affordable and optimal strategy for introducing more surface polarities and higher work functions for the improvement of charge transfer. Physical engineering includes the utilization of surface morphology control, and interlayer interactions, which can enhance the active interfacial area and electron transfer capacity. Structural engineering at the macroscale, which includes device and electrode design/modifications has a considerable effect on the performance of TENGs. Future challenges and promising research directions related to the construction of next-generation TENG devices, taking into consideration “interfaces” are also presented.

  • 31.
    Ahrenstedt, Lage
    et al.
    KTH. Cardiovascular Research Unit, University of Cape Town, South Africa.
    Hed, Yvonne
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Hult, Anders
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Zilla, Peter
    Cardiovascular Research Unit, University of Cape Town, South Africa.
    Bezuidenhout, Deon
    Cardiovascular Research Unit, University of Cape Town, South Africa.
    Malkoch, Michael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Sustained zero-order release of dexamethasone after incorporation into crosslinked PEG-dendrons using click reactions2024Ingår i: Journal of Drug Delivery Science and Technology, ISSN 1773-2247, Vol. 95, artikel-id 105637Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hydrogel-based localised drug delivery minimises systemic side effects and a linear release profile ensuring a sustained drug release over time, crucial for long-term therapy. The current paper describes the use of the Copper(I)-catalyzed Azide-Alkyne Cycloaddition (CuAAc) to append azidified Dexamethasone (Dex) onto dendrons of first- and second-generation PEGs. Crosslinking with thiolated PEGs using either thiol-acrylate or nucleophilic addition reactions yielded gels containing β-thio-ether ester groups that imparted enhanced hydrolytic susceptibility. In vitro gel degradation was followed gravimetrically and expressed as swelling ratios. Thiol-acrylate crosslinked hydrogels exhibited zero-order Dex release kinetics over 11, 27, and 16 days (G1, G1-star, and G2). Crosslinking the G1-gels by nucleophilic addition also resulted in linear release and the end point was reached in 5 days. Hydrolysis was accounted as the main release mechanism for covalently bound Dex, while physically incorporated Dex showed undefined rapid burst or first-order release, with most of the drug released in the initial 1–3 days. Eluates from covalently bound Dex maintained high activity, whereas Trap-Dex gels lost activity over time, as detected by the upregulation of luciferase expression from a transformed cell line. This novel chemistry combination offers precise drug release control applicable beyond Dex to drugs with suitable nucleophilic groups.

  • 32. Akinsinde, Lewis O.
    et al.
    Glier, Tomke E.
    Schwartzkopf, Matthias
    Betker, Marie
    Nissen, Matz
    Witte, Maximilian
    Scheitz, Sarah
    Nweze, Christian
    Grimm-Lebsanft, Benjamin
    Gensch, Marc
    Chumakov, Andrei
    Baev, Ivan
    Schurmann, Ulrich
    Dankwort, Torben
    Fischer, Frank
    Martins, Michael
    Roth, Stephan V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer. DESY, Notkestr 85, D-22607 Hamburg, Germany..
    Kienle, Lorenz
    Ruebhausen, Michael
    Surface characterization and resistance changes of silver-nanowire networks upon atmospheric plasma treatment2021Ingår i: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 550, artikel-id 149362Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Highly conductive silver-nanowire (Ag-NW) networks are used in composite materials as conductive channels. Their resistance tuning can be accomplished by changing the Ag-NW concentration, and, therefore, changing the network structure. In this study, an alternative pathway to resistance engineering of conductive Ag-NW networks by local atmospheric plasma treatment is employed. The corresponding changes in nanowire network morphology and crystallinity as a function of plasma etching time are investigated by time-resolved grazingincidence X-ray scattering, field-effect scanning electron microscopy, and X-ray photoelectron spectroscopy. Three characteristic etching phases are identified. The first two phases enable the controlled engineering of the electrical properties with different rates of resistance change, which results from changes in nanowire shape, network morphology, and different oxidation rates. Phase III is characterized by pronounced fragmentation and destruction of the Ag-NW networks. These results show the feasibility of atmospheric plasma treatments to tune the local electrical properties of conductive Ag-NW networks. Furthermore, we present a physical Monte Carlo model explaining the electrical network properties as a function of plasma etching time based on the network connectivity and a constant plasma etching rate of 570 ng s-1 cm-2.

  • 33.
    Al Husseinat, Ali
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Lignin Biorefining: Swelling and activation of fibers for lignin extraction2023Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I världens omvandling mot en bioekonomi kommer lignocellulosa material spela en stor roll i ersättningen av fossila resurser. Lignin är den mest tillgängliga källan av förnybara och naturligt förekommande aromatiska ämne och den utgör 15–30% av ved. Det lignin som är för nuvarande tillgängligt i marknaden är begränsat i sina appliceringar på grund av ämnets komplexa och outforskade kemisk struktur. I ett försök att bidra till ’lignin-först’ bioraffinaderi konceptet, undersöker detta arbete effekten av urea och karboxymetylering som förbehandlingsmetoder på utbyte av lignin såväl som de kemiska och fysiska egenskaperna av lignin. Karaktäriseringstekniker som Fourier-transform infra-red och nuclear magnetic resonance spectroscopy används för att analysera den kemiska strukturen av ligninet efter extraktion. Det resulterade i att båda förbehandlingsmetoder ökade utbytet av lignin med mellan 1% och 16%. Urea förbehandlingen hade ingen effekt på den kemiska strukturen av varken fibrer eller lignin. Men, karboxymetylering förbehandlingen ändrade i kemiska strukturen av lignin genom att lägga till karboxymetyl-grupper i både den alifatiska och den fenoliska regionen. Medans att öka förbehandlingstiden ökade utbyte i båda förbehandlingsmetoder, hade detta effekten att minska mängden kvantifierbara bindningar mellan enheterna för karboxymetylering förbehandlingen. Dessa diskuterade metoder har potential att användas i valorisering av lignin.

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  • 34.
    Alander, B.
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymera material.
    Capezza, A.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Polymera material. Department of Plant Breeding, The Swedish University of Agricultural Sciences, Box 101, Alnarp, Sweden.
    Wu, Qiong
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Johansson, E.
    Olsson, Richard T.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Hedenqvist, Mikael
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    A facile way of making inexpensive rigid and soft protein biofoams with rapid liquid absorption2018Ingår i: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 119, s. 41-48Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A novel and facile method to produce inexpensive protein biofoams suitable for sponge applications is presented. The protein used in the study was wheat gluten (WG), readily available as a by/co-product, but the method is expected to work for other cross-linkable proteins. The foams were obtained by high-speed stirring of pristine WG powder in water at room temperature followed by drying. Glutaraldehyde was used to crosslink the foam material in order to stabilize the dispersion, reduce its tackiness and improve the strength of the final foam. The foams were of medium to high density and absorbed readily both hydrophobic and hydrophilic liquids. The foam structure, consisting primarily of an open pore/channel system, led to a remarkably fast capillary-driven (pore-filling only) uptake of a hydrophobic liquid (limonene). Essentially all uptake occurred within the first second (to ca. 90% of the dry weight). In a polar liquid (water), the rapid pore-filling occurred in parallel with a more time-dependent swelling of the foam matrix material. Further improvement in the foam strength was achieved by making a denser foam or adding TEMPO-oxidized cellulose nanofibres. Soft foams were obtained by adding glycerol.

  • 35.
    Albers, Eva
    et al.
    Chalmers Univ Technol, Dept Biol & Biol Engn, Div Ind Biotechnol, SE-41296 Gothenburg, Sweden..
    Malmhall-Bah, Eric
    Chalmers Univ Technol, Dept Biol & Biol Engn, Div Ind Biotechnol, SE-41296 Gothenburg, Sweden..
    Olsson, Joakim
    Chalmers Univ Technol, Dept Biol & Biol Engn, Div Ind Biotechnol, SE-41296 Gothenburg, Sweden..
    Sterner, Martin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Vatten- och miljöteknik.
    Mayers, Joshua J.
    Chalmers Univ Technol, Dept Biol & Biol Engn, Div Ind Biotechnol, SE-41296 Gothenburg, Sweden..
    Nylund, Goran M.
    Univ Gothenburg, Dept Marine Sci Tjarno, SE-45296 Stromstad, Sweden..
    Rupar-Gadd, Katarina
    Linnaeus Univ, Dept Built Environm & Energy Technol, Luckligs Plats 3, SE-35195 Växjö, Sweden..
    Abdollahi, Mehdi
    Chalmers Univ Technol, Dept Biol & Biol Engn, Div Food & Nutr Sci, SE-41296 Gothenburg, Sweden..
    Cvijetinovic, Suzana
    Chalmers Univ Technol, Dept Biol & Biol Engn, Div Ind Biotechnol, SE-41296 Gothenburg, Sweden..
    Welander, Ulrika
    Linnaeus Univ, Dept Built Environm & Energy Technol, Luckligs Plats 3, SE-35195 Växjö, Sweden..
    Edlund, Ulrica
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Pavia, Henrik
    Univ Gothenburg, Dept Marine Sci Tjarno, SE-45296 Stromstad, Sweden..
    Undeland, Ingrid
    Chalmers Univ Technol, Dept Biol & Biol Engn, Div Food & Nutr Sci, SE-41296 Gothenburg, Sweden..
    Influence of preservation methods on biochemical composition and downstream processing of cultivated Saccharina latissima biomass2021Ingår i: Algal Research, ISSN 2211-9264, Vol. 55, artikel-id 102261Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Saccharina latissima biomass cultivated along the Swedish west coast was subjected to four different scalable preservation methods after harvest; freezing, sun-drying, oven-drying and ensiling. Freeze-drying and freezing at -80 ?C were also included to provide dry and wet references. The effects of the different preservation methods on the composition of Saccharina biomass (on dry weight, DW, basis), and the recovery as well as properties of high-quality protein, alginate and biogas were evaluated. Sun-drying significantly reduced protein, alginate and fatty acid content of the seaweeds and thereby concentrated ash in the biomass compared to the other methods. Protein/amino acids and fatty acids were significantly concentrated in ensiled biomass, while mannitol and laminarin were reduced compared to the other biomasses. Oven-drying and -20 ?C freezing affected the composition the least, with lower ash content and alterations in some specific amino and fatty acids. Sun-drying and ensiling resulted in significantly lower protein solubility at high pH compared to the other biomasses which translated into the lowest total seaweed protein recovery using the pH-shift process. Highest protein yield was obtained with the freeze-dried reference. Ensiling lead to a significant decrease in the molecular weight of alginate, while sun-drying caused a negative effect on alginate by inducing a shift in the guluronic and mannuronic acids composition of alginate. Sun-drying gave the lowest methane yield in the anaerobic digestion experiments while freezing at -80 ?C gave the highest yield, closely followed by freezing at -20 ?C and ensiling. To conclude, preservation methods must be carefully chosen to protect the valuable component in Saccharina latissima, and to achieve an efficient downstream processing ultimately yielding high quality products as part of a seaweed biorefinery.

  • 36.
    Albertsson, Ann-Christine
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Celebrating 20 years of Biomacromolecules!2019Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, nr 2, s. 767-768Artikel i tidskrift (Refereegranskat)
  • 37.
    Albertsson, Ann-Christine
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    CELL 104-Renewable and/or degradable polymers2007Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 233, s. 796-796Artikel i tidskrift (Övrigt vetenskapligt)
  • 38.
    Albertsson, Ann-Christine
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Micro- and macromolecular design of aliphatic polyesters2015Ingår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 249Artikel i tidskrift (Övrigt vetenskapligt)
  • 39.
    Albertsson, Ann-Christine
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Karlsson, Sigbritt
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Biodegradation and test methods for environmental and biomedical applications of polymers2018Ingår i: Degradable Materials: Perspectives, Issues, and Opportunities, CRC Press , 2018, s. 263-293Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 40.
    Albertsson, Ann-Christine
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Percec, Simona
    Future of Biomacromolecules at a Crossroads of Polymer Science and Biology2020Ingår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 21, nr 1, s. 1-6Artikel i tidskrift (Refereegranskat)
  • 41.
    Albertsson, Ann-Christine
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Varma, Indra Kumari
    Centre for Polymer Science and Engineering, Indian Institute of Technology, New Delhi, India.
    Lochab, Bimlesh
    Materials Research Laboratory, Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Greater Noida, India.
    Finne Wistrand, Anna
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Sahu, Sangeeta
    Materials Research Laboratory, Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Tehsil Dadri, India.
    Kumar, Kamlesh
    Council of Scientific and Industrial Research, Central Scientific Instruments Organization, Chandigarh, India.
    Design and synthesis of different types of poly(lactic acid)/polylactide copolymers2022Ingår i: Poly(lactic acid): Synthesis, Structures, Properties, Processing, Applications, and End of Life, Wiley , 2022, s. 45-71Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    High molar mass poly(lactic acid) (PLA) is obtained by either the polycondensation of lactic acid or ring-opening polymerization (ROP) of the cyclic dimer 2,6-dimethyl-1,4-dioxane-2,5-dione, commonly referred to as dilactide or lactide (LA). This chapter describes preparation of polymers and copolymers of LAs with different structures, using polycondensation and ROP. Typical comonomers and polymers which are used for lactic acid or LA copolymerization include glycolic acid or glycolide, poly(ethylene glycol) or poly(ethylene oxide), and so on. PLAs having amino, carboxyl, or other functional groups are well reported in the literature. These functional groups can be utilized for chemical modification or as binding sites for biomolecules to impart selective binding and adhesion. PLA and its copolymers especially when used for biological applications, besides requirement of optimization of mechanical properties by engineering at the molecular level, also demands a fast degradation polymer rate.

  • 42.
    Albinsson, Emmy
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Tafesse Belachew, Helina
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Swaich, Jasmin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Juhlin, Hannah
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Novel materials from lignocellulosic sources- can they replace thermoplastics?2021Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Plastavfall är ett allvarligt miljöproblem i dagens samhälle som uppmärksammats mycket under de senaste åren. En ständig ökning i produktionen under de senaste decennier har lett till att stora mängder plast hamnat i haven där de sönderdelas till mikroplaster. Med strängare krav av plastanvändning från Europaparlamentet har nya alternativa plaster som är biobaserade och därmed nedbrytbara ökat i efterfråga. Målet med detta projekt var därför att syntetisera ett lignocellulosabaserat material som innehåller så lite icke-nedbrytbar latex, plastkomponenten, som möjligt utan att behöva mista de egenskaper som efterfrågas av termoplaster idag. Den ursprungliga idén var att syntetisera latexen genom PISA-RAFT tekniken, dessvärre pga rådande omständigheter gällande COVID-19 var detta inte möjligt då materialen som behövdes inte kunde levereras. Därför syntetiserades latexen genom emulsionspolymerisation istället.

    På grund av problem med halmen skapades två olika typer av kompositer, halm kompositer och filterpapper kompositer. De två kompositerna gjordes i två varianter, en innehållande latex A och en med latex B. Latex A och B syntetiserades av olika mängd monomerer vilka var metakrylsyra (MAA) och metylmetakrylat (MMA). Både latex A och B innehöll 75 % av monomeren vinylacetat (VAc). Olika karakteriseringsmetoder, FE-SEM, DLS, DSC, FTIR, NMR, TGA och tensile test utfördes på kompositerna.

    NMR och DSC analyserna indikerade att den analyserade kompositionen av monomererna skiljer sig åt från den teoretiska kompositionen då närvaron av MAA var svår att detektera. FTIR analysen motsäger dock de analyserade värdena av NMR och DSC då MAA tros ha detekteras då. För jämförelsen av latex A och B resulterade DLS i lägre PDI och större emulsions sfärer för latex A vilket föredras vid produktion av kompositer. Genom analys av tensile test uppnådde latex B högre värden för Young`s modul och max stress medans latex A uppnådde högre värden för belastning vid brottet. TGA och DSC analysen resulterade dock i högre Tg och högre termisk stabilitet för latex B. Den övergripande analysen indikerade att latex B var det mer optimala valet för kompositproduktion meden liten skillnad i jämförelse.

    Analysen av kompositerna genom FE-SEM indikerade att interaktionen mellan latex och filterpapper var högre än latex och halmen. Total skapades fyra halm kompositer med halm:latex viktförhållandet 50:50 och 75:50 för både latex A och B. Till följd av att halmen inte kunde malas ned till den minimala storleken som behövdes för att bilda kompositer, kunde endast FE-SEM och FTIR analyser utföras. På grund av detta kunde ingen slutsats dras om vilket viktförhållande, 50:50 eller 75:50, som bildade den mest optimala kompositen. 

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  • 43.
    Alexakis, Alexandros Efraim
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Nanolatexes: a versatile toolbox for cellulose modification2023Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [sv]

    Cellulosamaterial används i stor utsträckning i vår vardag, i allt från papper och förpackningar till biomedicinska tillämpningar. Men i de flesta tillämpningar måste cellulosa samexistera med hydrofoba polymerer, vilket kan vara utmanande på grund av cellulosas hydrofila karaktär. Detta har lett till betydande forskning på kemiska och fysikalisk modifiering av cellulosa.

    Projekten som ingår i denna avhandling fokuserar på icke-kovalent modifiering av cellulosamaterial med skräddarsydda, mycket mångsidiga kolloidala nanopartiklar syntetiserade i vatten, så kallade nanolatex-partiklar. Syntesen av dem är baserad på kombinationen av reversibel addition-fragmentation chain transfer (RAFT) polymerisation med ”polymerisationsinducerad självorganisering” (PISA). Kombinationen av dessa tekniker resulterar i bildningen av amfifila diblock-sampolymerer som självorganiseras i vatten till att bilda en mängd olika morfologier. Sfärer, worms och vesiklar med pH-känsliga skalpolymerer bereddes för att undersöka vilka reaktionsparametrar som resulterar i övergång mellan olika morfologier. Mindre undersökta parametrar som den kemiska sammansättningen av RAFT-agenten studerades vilket resulterade i bildandet av bimodala nanolatexer med opalliknande egenskaper på ett reproducerbart sätt.

    En grundläggande undersökning av parametrarna som styr adsorptionen av katjoniskt laddade nanolatex-partiklar på silika och regenererade cellulosamodellytor (TEMPO-oxiderad cellulosa) genomfördes också. Kombinationen av gravimetriska och reflektometriska tekniker avslöjade komplexiteten hos modellytan. Både storleken och laddningstätheten hos nanolatexarna visade sig påverka deras adsorption. Informationen från denna studie implementerades vid framställningen av cellulosa nanofibril (CNF)-nanokompositer med låga halter av nanolatexer. Det visade sig att när nanolatexhalten var under 1 viktprocent förbättrades den mekaniska egenskapsprofilen för CNF-nanokompositerna. 

    Slutligen användes träbaserade komponenter för att ersätta fossilbaserade monomerer i nanolatexer. De adsorberades lätt på filterpapper (cellulosa) och anlöptes vid en temperatur över glasomvandlingstemperaturen, vilket demonstrerade deras filmbildningskapacitet. Nanolatexer som består av en träbaserad skalpolymer har en lovande egenskapsprofil för high-end tillämpningar vilket t ex framgår av deras interaktioner med Cu(II)-joner, där nanolatex-partiklarna förhindrade bildandet av Cu(II)-jonaggregat. 

    Resultaten som sammanfattas i denna avhandling bidrar till förståelsen om icke-kovalent modifiering av cellulosa och är också avsedda att ytterligare främja användningen av träbaserade monomerer i produktionen av polymererna för avancerade applikationer.

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  • 44.
    Alexakis, Alexandros Efraim
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Ayyachi, Thayanithi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Mousa, Maryam
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Olsen, Peter
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Biokompositer.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    2-Methoxy-4-Vinylphenol as a Biobased Monomer Precursor for Thermoplastics and Thermoset Polymers2023Ingår i: Polymers, E-ISSN 2073-4360, Vol. 15, nr 9, artikel-id 2168Artikel i tidskrift (Refereegranskat)
    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.

  • 45.
    Alexakis, Alexandros Efraim
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Engström, Joakim
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Stamm, Arne
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Riazanova, Anastasia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. Wallenberg Wood Sci Ctr WWSC, Tekn Ringen 56-58, SE-10044 Stockholm, Sweden..
    Brett, Calvin
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, Hamburg, 22603, Germany.
    Roth, Stephan V.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, Hamburg, 22603, Germany.
    Syrén, Per-Olof
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Fogelström, Linda
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Reid, Michael S.
    KTH, Skolan för teknikvetenskap (SCI), Teknisk mekanik.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Modification of cellulose through physisorption of cationic bio-based nanolatexes - comparing emulsion polymerization and RAFT-mediated polymerization-induced self-assembly2021Ingår i: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 23, nr 5, s. 2113-2122Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The polymerization of a bio-based terpene-derived monomer, sobrerol methacrylate (SobMA), was evaluated in the design of polymeric nanoparticles (nanolatexes). Their synthesis was accomplished by using emulsion polymerization, either by free-radical polymerization in the presence of a cationic surfactant or a cationic macroRAFT agent by employing RAFT-mediated polymerization-induced self-assembly (PISA). By tuning the length of the hydrophobic polymer, it was possible to control the nanoparticle size between 70 and 110 nm. The average size of the latexes in both wet and dry state were investigated by microscopy imaging and dynamic light scattering (DLS). Additionally, SobMA was successfully copolymerized with butyl methacrylate (BMA) targeting soft-core nanolatexes. The comparison of the kinetic profile of the cationically stabilized nanolatexes highlighted the differences of both processes. The SobMA-based nanolatexes yielded high T-g similar to 120 degrees C, while the copolymer sample exhibited a lower T-g similar to 50 degrees C, as assessed by Differential Scanning Calorimetry (DSC). Thereafter, the nanolatexes were adsorbed onto cellulose (filter paper), where they were annealed at elevated temperatures to result in polymeric coatings. Their morphologies were analysed by Field Emission Scanning Electron Microscopy (FE-SEM) and compared to a commercial sulfate polystyrene latex (PS latex). By microscopic investigation the film formation mechanism could be unravelled. Water contact angle (CA) measurements verified the transition from a hydrophilic to a hydrophobic surface after film formation had occured. The obtained results are promising for the toolbox of bio-based building blocks, focused on sobrerol-based monomers, to be used in emulsion polymerizations either for tailored PISA-latexes or facile conventional latex formation, in order to replace methyl methacrylate or other high T-g-monomers.

  • 46.
    Alexakis, Alexandros Efraim
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Jerlhagen, Åsa
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Telaretti Leggieri, Rosella
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Eliasson, Adrian
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Benselfelt, Tobias
    School of Materials Science and Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Modification of CNF‐Networks by the Addition of Small Amounts of Well‐Defined Rigid Cationic Nanolatexes2022Ingår i: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 224, nr 1, s. 2200249-2200249Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cellulose nanofibril (CNF)-networks are modified by the addition of small amounts (below 10 wt%) of well-defined cationic nanolatexes synthesized through reversible addition–fragmentation chain-transfer-mediated polymerization-induced self-assembly (PISA). Minute amounts of nanolatex inclusions lead to increased tensile and shear moduli, indicating that nanolatexes can act as bridging-points between CNFs. At higher nanolatex content, this stiffening effect is lost, likely due to interactions between nanolatexes leading to plasticization. The influence of nanolatex content and size on interparticle distance is discussed and is used as a tool to understand the effects observed in macroscopic properties. Upon annealing, the stiffening effect is lost due to the softening of the nanolatexes, indicating that the core–shell morphology is a prerequisite for this effect. These systems form a versatile platform to develop fundamental insights into complex condensed colloidal systems, to ultimately aid in the development of new sustainable material concepts.

  • 47.
    Alexakis, Alexandros Efraim
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    pH-Responsive nanolatexes stabilized by statistical copolymers obtained by RAFT-mediated PISAManuskript (preprint) (Övrigt vetenskapligt)
  • 48.
    Alexakis, Alexandros Efraim
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Riazanova, Anastasia
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Bio-based nanolatexes prepared via polymerization-induced self-assembly: targeting heavy metal capturing applicationsManuskript (preprint) (Övrigt vetenskapligt)
  • 49.
    Alexakis, Alexandros Efraim
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Telaretti Leggieri, Rosella
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Wågberg, Lars
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Benselfelt, Tobias
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Fiberteknologi. School of Materials Science and Engineering, Nanyang Technological University, 639798 Singapore, Singapore.
    Nanolatex architectonics: Influence of cationic charge density and size on their adsorption onto surfaces with a 2D or 3D distribution of anionic groups2023Ingår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 634, s. 610-620Artikel i tidskrift (Refereegranskat)
  • 50.
    Alexakis, Alexandros Efraim
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center.
    Wilson, Olivia R.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Malmström, Eva
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Centra, Wallenberg Wood Science Center. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Fiber- och polymerteknologi, Ytbehandlingsteknik.
    Bimodal nanolatexes prepared via polymerization-induced self-assembly: losing control in a controlled mannerManuskript (preprint) (Övrigt vetenskapligt)
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