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Rahimi-Aghdam, T., Shariatinia, Z., Hakkarainen, M. & Haddadi-Asl, V. (2020). Nitrogen and phosphorous doped graphene quantum dots: Excellent flame retardants and smoke suppressants for polyacrylonitrile nanocomposites. Journal of Hazardous Materials, 381, Article ID 121013.
Open this publication in new window or tab >>Nitrogen and phosphorous doped graphene quantum dots: Excellent flame retardants and smoke suppressants for polyacrylonitrile nanocomposites
2020 (English)In: Journal of Hazardous Materials, ISSN 0304-3894, E-ISSN 1873-3336, Vol. 381, article id 121013Article in journal (Refereed) Published
Abstract [en]

Nitrogen (N-GQD) as well as nitrogen and phosphorous co-doped (NP-GQD) graphene quantum dots were demonstrated as novel, low cost, green and highly effective flame retardants and smoke suppressants for polyacrylonitrile (PAN) nanocomposites. The N-GQD and NP-GQD samples were synthesized by hydrothermal method with citric acid as the main reactant. For the first time, the flame retardant and smoke suppressant properties of the NP-GQD were studied. The GQDs were introduced into PAN by solvent blending route. Subsequently, thermal stability, flame retardancy, fire behavior, fire hazard and structure of the residual char were investigated by thermogravimetric analysis (TGA), UL-94 vertical burning test, cone calorimetry, FE-SEM, and Raman spectroscopy. Results showed that both PAN/N-GQD and PAN/NP-GQD nanocomposites had higher flame retardancy and smoke suppressant behavior in addition to lower fire hazard properties than neat PAN. Furthermore, the residual chars for the nanocomposite samples were increased in comparison to the neat PAN. The improvements were even more significant in case of the PAN/NP-GQD due to the synergistic effect of nitrogen and phosphorous. The improvements were mainly ascribed to the ability of the N-GQD and NP-GQD to provide stronger and larger protective char barrier layers, which was even more pronounced in case of the NP-GQD.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Char barrier layer, Fire hazard, Flame retardant, N and P co-doped graphene quantum dot (NP-GQD), Polyacrylonitrile (PAN), Smoke suppressant, Blending, Fire hazards, Fires, Flame retardants, Graphene, Nanocomposites, Nanocrystals, Nitrogen, Phosphorus, Semiconductor quantum dots, Thermogravimetric analysis, Barrier layers, Co-doped, Hydrothermal methods, Nanocomposite samples, Smoke suppressant properties, Smoke suppressants, Vertical burning tests, Smoke, carbon, graphene oxide, nanocomposite, polyacrylonitrile, quantum dot, burning, citric acid, quantum mechanics, solvent, Article, chemical structure, controlled study, field emission scanning electron microscopy, fire, heat, synergistic effect, synthesis, thermostability, X ray diffraction
National Category
Polymer Technologies
Research subject
Fibre and Polymer Science; Physics, Material and Nano Physics
Identifiers
urn:nbn:se:kth:diva-263435 (URN)10.1016/j.jhazmat.2019.121013 (DOI)2-s2.0-85070915285 (Scopus ID)
Note

QC 20191205

Available from: 2019-12-05 Created: 2019-12-05 Last updated: 2019-12-05Bibliographically approved
Pronoitis, C., Hua, G., Hakkarainen, M. & Odelius, K. (2019). Biobased Polyamide Thermosets: From a Facile One-Step Synthesis to Strong and Flexible Materials. Macromolecules, 52(16), 6181-6191
Open this publication in new window or tab >>Biobased Polyamide Thermosets: From a Facile One-Step Synthesis to Strong and Flexible Materials
2019 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 52, no 16, p. 6181-6191Article in journal (Refereed) Published
Abstract [en]

Biobased polyamide (PA) thermosets composed of renewable ethylene brassylate were synthesized through a one-step reaction under solvent-free conditions, at 100 degrees C in the presence of an organocatalyst. Under these conditions, thermoset formation times as low as 10 min were achieved. The thermosets were easily prepared as thin, transparent films with high strength, flexibility, and high thermal stability. The ester-to-amine content and formation of ethylene glycol in situ as a byproduct of the reaction were studied and correlated with the final properties of the materials. Crystalline oligoester segments were identified as a result of ring-opening polymerization and were shown to have a beneficial effect on the mechanical properties of the thermosets and endowed shape-memory behavior. In contrast to other routes, employing multistep monomer preparation, harsh conditions, and chlorinated reagents, this procedure contributed to the development of sustainable, functional PA thermosets.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-260186 (URN)10.1021/acs.macromol.9b00359 (DOI)000483437500015 ()2-s2.0-85071380280 (Scopus ID)
Note

QC 20190930

Available from: 2019-09-30 Created: 2019-09-30 Last updated: 2019-09-30Bibliographically approved
Hakkarainen, M. (2019). Carbon dots as bioactivity inducers in polymeric biomaterials. Paper presented at National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL. Abstracts of Papers of the American Chemical Society, 257
Open this publication in new window or tab >>Carbon dots as bioactivity inducers in polymeric biomaterials
2019 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-257607 (URN)000478860502765 ()
Conference
National Meeting of the American-Chemical-Society (ACS), MAR 31-APR 04, 2019, Orlando, FL
Note

QC 20190919

Available from: 2019-09-19 Created: 2019-09-19 Last updated: 2019-11-12Bibliographically approved
Gazzotti, S., Rampazzo, R., Hakkarainen, M., Bussini, D., Ortenzi, M. A., Farina, H., . . . Silvani, A. (2019). Cellulose nanofibrils as reinforcing agents for PLA-based nanocomposites: An in situ approach. Composites Science And Technology, 171, 94-102
Open this publication in new window or tab >>Cellulose nanofibrils as reinforcing agents for PLA-based nanocomposites: An in situ approach
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2019 (English)In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 171, p. 94-102Article in journal (Refereed) Published
Abstract [en]

One-pot in situ polymerization approach was explored for the preparation of polylactide (PLA)-cellulose nano-fibril (CNF) bio-nanocomposites. CNF were first prepared through enzymatic and mechanical treatment of bleached hardwood kraft pulp. The bio-nanocomposites- were then fabricated through ring opening polymerization (ROP) of L-lactide, in the presence of various amounts of fibrils. Molecular weight, thermal properties, surface morphology, mechanical and wettability properties of the PLA-CNF nanocomposites were evaluated. DSC analysis demonstrated the effect of CNF on crystallization and crystalline morphology of PLA. Improved modulus for the nanocomposites with respect to standard PLA was demonstrated, however, the differences in tensile stress were small probably due to the counteracting effects of reinforcement from CNF and the decreasing molecular weight as a function of CNF concentration. The absence of pulled-out fibers was assessed, highlighting the strong interface and covalent attachment of PLA chains on CNF surface. Finally, the covalent bonding of PLA chains on CNF surface was demonstrated by isolating the non-soluble part, consisting of PLA-grafted CNF, and characterization of this residue.

Place, publisher, year, edition, pages
ELSEVIER SCI LTD, 2019
Keywords
Fibers, Nano composites, Polymers, Short-fibre composites, Interfacial strength
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-244094 (URN)10.1016/j.compscitech.2018.12.015 (DOI)000457505600011 ()2-s2.0-85058640232 (Scopus ID)
Note

QC 20190219

Available from: 2019-02-19 Created: 2019-02-19 Last updated: 2019-02-19Bibliographically approved
Erdal, N. B., Yao, J. G. & Hakkarainen, M. (2019). Cellulose-Derived Nanographene Oxide Surface-Functionalized Three-Dimensional Scaffolds with Drug Delivery Capability. Paper presented at Symposium on Rational Design of Multifunctional Renewable-Resourced Materials held during the ACS National Meeting, AUG 19-23, 2018, Boston, MA. Biomacromolecules, 20(2), 738-749
Open this publication in new window or tab >>Cellulose-Derived Nanographene Oxide Surface-Functionalized Three-Dimensional Scaffolds with Drug Delivery Capability
2019 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, no 2, p. 738-749Article in journal (Refereed) Published
Abstract [en]

Multifunctional three-dimensional (3D) scaffolds were targeted by surface grafting cellulose-derived nanographene oxide (nGO) on the surface of porous poly(epsilon-caprolactone) (PCL) scaffolds. nGO was derived from cellulose by microwave-assisted carbonization process and covalently grafted onto aminolyzed PCL scaffolds through an aqueous solution process. Fourier transform infrared spectroscopy and thermogravimetric analysis both verified the successful attachment of nGO and scanning electron microscopy depicted a homogeneous dispersion of nGO over the scaffold surface. Mechanical tests were performed and demonstrated a significant increase in compressive strength for the nGO grafted scaffolds. Grafting of nGO was also shown to induce mineralization with the formation of calcium phosphate precipitates on the surface of the scaffolds with the size increasing with higher nGO content. The potential of surface-grafted nGO as a nanocarrier of an antibiotic drug was also explored. The secondary interactions between nGO and ciprofloxacin, a broad-spectrum antibiotic used in the treatment of osteomyelitis, were optimized by controlling the solution pH. Ciprofloxacin was found to be adsorbed most strongly in its cationic form at pH 5, in which pi-pi electron donor-acceptor interactions predominate and the adsorbed drug content increased with increasing nGO amount. Further, the release kinetics of the drug were investigated during 8 days. In conclusion, the proposed simple fabrication process led to a scaffold with multifunctionality in the form of improved mechanical strength, ability to induce mineralization, as well as drug loading and delivery capability.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:kth:diva-245945 (URN)10.1021/acs.biomac.8b01421 (DOI)000458937200017 ()30360619 (PubMedID)2-s2.0-85056460762 (Scopus ID)
Conference
Symposium on Rational Design of Multifunctional Renewable-Resourced Materials held during the ACS National Meeting, AUG 19-23, 2018, Boston, MA
Note

QC 20190313

Available from: 2019-03-13 Created: 2019-03-13 Last updated: 2019-03-13Bibliographically approved
Bäckström, E., Odelius, K. & Hakkarainen, M. (2019). Designed from Recycled: Turning Polyethylene Waste to Covalently Attached Polylactide Plasticizers. ACS SUSTAINABLE CHEMISTRY & ENGINEERING, 7(12), 11004-11013
Open this publication in new window or tab >>Designed from Recycled: Turning Polyethylene Waste to Covalently Attached Polylactide Plasticizers
2019 (English)In: ACS SUSTAINABLE CHEMISTRY & ENGINEERING, ISSN 2168-0485, Vol. 7, no 12, p. 11004-11013Article in journal (Refereed) Published
Abstract [en]

High-density polyethylene (HDPE) waste was successfully feedstock recycled, and the obtained chemicals were utilized for synthesis of plasticizers for polylactide (PLA). First, an effective route to recycle HDPE through a microwave-assisted hydrothermal process was established. This process led to selective degradation of HDPE to a few well-defined chemicals, namely, succinic, glutaric, and adipic acid. A model plasticizer was synthesized from the same composition of dicarboxylic acids, 1,4-butanediol, and crotonic acid. The function of crotonic acid was to produce oligomers with crotonate end groups for coupling the plasticizer to PLA main chain. The plasticizer was then blended with or coupled to PLA by a reactive extrusion process. Adding the plasticizer to PLA decreased the T-g and increased the strain at break, thus reducing the brittleness of the films. The addition of 20% (w/w) grafted plasticizer increased the strain at break of PLA from 6 to 156% and decreased the T-g by 15 degrees C compared with neat PLA. Finally, to verify the concept, a plasticizer was also synthesized from the dicarboxylic acid product mixture obtained from the feedstock recycling of HDPE. The recycled grafted plasticizer increased the strain at break of PLA to 142% and reduced the T-g by 10 degrees C. A promising route for designing from recycled feedstock, turning HDPE waste to PLA plasticizers, was thus demonstrated.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
Keywords
HDPE, Oxidative degradation, Feedstock recycling, PLA, Plasticization
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-255190 (URN)10.1021/acssuschemeng.9b02092 (DOI)000472240900091 ()2-s2.0-85067031627 (Scopus ID)
Note

QC 20190904

Available from: 2019-09-04 Created: 2019-09-04 Last updated: 2019-09-04Bibliographically approved
Delekta, S. S., Adolfsson, K. H., Benyahia Erdal, N., Hakkarainen, M., Östling, M. & Li, J. (2019). Fully inkjet printed ultrathin microsupercapacitors based on graphene electrodes and a nano-graphene oxide electrolyte. Nanoscale, 11(21), 10172-10177
Open this publication in new window or tab >>Fully inkjet printed ultrathin microsupercapacitors based on graphene electrodes and a nano-graphene oxide electrolyte
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2019 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 11, no 21, p. 10172-10177Article in journal (Refereed) Published
Abstract [en]

The advance of miniaturized and low-power electronics has a striking impact on the development of energy storage devices with constantly tougher constraints in terms of form factor and performance. Microsupercapacitors (MSCs) are considered a potential solution to this problem, thanks to their compact device structure. Great efforts have been made to maximize their performance with new materials like graphene and to minimize their production cost with scalable fabrication processes. In this regard, we developed a full inkjet printing process for the production of all-graphene microsupercapacitors with electrodes based on electrochemically exfoliated graphene and an ultrathin solid-state electrolyte based on nano-graphene oxide. The devices exploit the high ionic conductivity of nano-graphene oxide coupled with the high electrical conductivity of graphene films, yielding areal capacitances of up to 313 mu F cm-2 at 5 mV s-1 and high power densities of up to 4 mW cm-3 with an overall device thickness of only 1 mu m.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2019
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-254076 (URN)10.1039/c9nr01427f (DOI)000470697800002 ()31107494 (PubMedID)2-s2.0-85066626832 (Scopus ID)
Note

QC 20190624

Available from: 2019-06-24 Created: 2019-06-24 Last updated: 2019-08-16Bibliographically approved
Adolfsson, K. H., Golda-Cepa, M., Benyahia Erdal, N., Duch, J., Kotarba, A. & Hakkarainen, M. (2019). Importance of Surface Functionalities for Antibacterial Properties of Carbon Spheres. Advanced Sustainable Systems
Open this publication in new window or tab >>Importance of Surface Functionalities for Antibacterial Properties of Carbon Spheres
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2019 (English)In: Advanced Sustainable Systems, ISSN 2366-7486Article in journal (Refereed) Published
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.

Keywords
antibacterial; carbon spheres; carbonization; electrostatic interactions; microwaves; surface functionality
National Category
Natural Sciences
Identifiers
urn:nbn:se:kth:diva-248712 (URN)10.1002/adsu.201800148 (DOI)000465001800001 ()
Note

QC 20190514

Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-05-14Bibliographically approved
Xuan, W., Hakkarainen, M. & Odelius, K. (2019). Levulinic Acid as a Versatile Building Block for Plasticizer Design. ACS Sustainable Chemistry and Engineering, 7(14), 12552-12562
Open this publication in new window or tab >>Levulinic Acid as a Versatile Building Block for Plasticizer Design
2019 (English)In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 7, no 14, p. 12552-12562Article in journal (Refereed) Published
Abstract [en]

The large potential of utilizing green platform chemicals such as levulinic acid, glycerol, and ethylene glycol as building blocks for the design of high-performance biobased plasticizers was demonstrated. From these green platform chemicals, esters with ketal or ketone functionalities and linear or branched structures were carefully designed and synthesized via a mild and solvent-free route and characterized by H-1 NMR, C-13 NMR, and FTIR. The effect of the structural combinations on the performance as plasticizers for polylactide (PLA), including migration resistance, was followed by a series of characterization techniques. The levulinates with ketone end-groups exhibited large capability to lower the glass transition temperature (T-g) of PLA (to 15 degrees C by 20 wt % plasticizer). Ketal end-groups provided additional thermal stability to the plasticizers, but their ability to lower T-g was not as good as that of ketone end-groups. Significantly improved flexibility reaching 546% elongation at break was achieved by the addition of 20 wt % ethylene glycol dilevulinate, as compared to 5% elongation at break for neat PLA. The structural differences for the plasticizers resulted in different degrees of hydrophobicity, which influenced the migration tendency of the plasticizers and also the hydrolysis rate of PLA. The branched ester structure with ketal end-groups maintained the processing window of PLA, but also lowered the hydrolysis rate of PLA in an accelerated migration test. In general, performance comparable to that of the reference plasticizer acetyl tributyl citrate (ATBC) was demonstrated, offering promise for a family of plasticizers derivable from green platform chemicals.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2019
Keywords
Plasticizer, Levulinic acid, Polylactide, Migration, Acetyl tributyl citrate
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-255558 (URN)10.1021/acssuschemeng.9b02439 (DOI)000475838100067 ()2-s2.0-85068486097 (Scopus ID)
Note

QC 20190805

Available from: 2019-08-05 Created: 2019-08-05 Last updated: 2019-10-04Bibliographically approved
Bianchi, F., Agazzi, S., Riboni, N., Benyahia Erdal, N., Hakkarainen, M., Ilag, L. L., . . . Careri, M. (2019). Novel sample-substrates for the determination of new psychoactive substances in oral fluid by desorption electrospray ionization-high resolution mass spectrometry. Talanta: The International Journal of Pure and Applied Analytical Chemistry, 202, 136-144
Open this publication in new window or tab >>Novel sample-substrates for the determination of new psychoactive substances in oral fluid by desorption electrospray ionization-high resolution mass spectrometry
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2019 (English)In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 202, p. 136-144Article in journal (Refereed) Published
Abstract [en]

A reliable screening and non invasive method based on the use of microextraction by packed sorbent coupled with desorption electrospray ionization-high resolution mass spectrometry was developed and validated for the detection of new psychoactive substances in oral fluid. The role of different sample substrates in enhancing signal intensity and stability was evaluated by testing the performances of two polylactide-based materials, i.e. non-functionalized and functionalized with carbon nanoparticles, and a silica-based material compared to commercially available polytetrafluorethylene supports. The best results were achieved by using the non-functionalized polylactide substrates to efficiently ionize compounds in positive ionization mode, whereas the silica coating proved to be the best choice for operating in negative ionization mode. LLOQs in the low μg/L, a good precision with CV% always lower than 16% and RR% in the 83(±4)-120(±2)% range, proved the suitability of the developed method for the determination of the analytes in oral fluid. Finally, the method was applied for screening oral fluid samples for the presence of psychoactive substances during private parties, revealing mephedrone in only one sample out of 40 submitted to analysis.

Place, publisher, year, edition, pages
Elsevier B.V., 2019
Keywords
Desorption electrospray ionization, High resolution mass spectrometry, New psychoactive substances, Sample-substrates, Desorption, Mass spectrometry, Noninvasive medical procedures, Polyesters, Screening, Silica, Carbon Nano-Particles, Micro-extraction by packed sorbents, Noninvasive methods, Polytetrafluorethylene, Silica based materials, Electrospray ionization
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-252452 (URN)10.1016/j.talanta.2019.04.057 (DOI)000472693700015 ()2-s2.0-85064881748 (Scopus ID)
Note

QC 20190715

Available from: 2019-07-15 Created: 2019-07-15 Last updated: 2019-07-29Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-7790-8987

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