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  • 1.
    Brännström, Sara
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Finnveden, Maja
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Razza, Nicolo
    Politecn Torino, Dept Appl Sci & Technol, Corso Duca Abruzzi 24, I-10129 Turin, Italy..
    Martinelle, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sangermano, Marco
    Politecn Torino, Dept Appl Sci & Technol, Corso Duca Abruzzi 24, I-10129 Turin, Italy..
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Tailoring Thermo-Mechanical Properties of Cationically UV-Cured Systems by a Rational Design of Vinyl Ether Ester Oligomers using Enzyme Catalysis2018In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 219, no 21, article id 1800335Article in journal (Refereed)
    Abstract [en]

    There is a demand for new sustainable polymeric materials. Vinyl ethers are, in this context, attractive oligomers since they polymerize fast, are non-toxic, and can be polymerized under ambient conditions. The availability of vinyl ether oligomers is, however, currently limited due to difficulties in synthesizing them without using tedious synthesis routes. This work presents the synthesis of a series of vinyl ether ester oligomers using enzyme catalysis under solvent-free conditions and the subsequent photoinduced cationic polymerization to form polymer thermosets with T(g)s ranging from -10 to 100 degrees C. The whole process is very efficient as the synthesis takes less than 1 h with no need for purification and the crosslinking is complete within 2 min.

  • 2.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Tailoring cellulose surfaces by controlled polymerization methods2013In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 214, no 14, p. 1539-1544Article in journal (Refereed)
    Abstract [en]

    Cellulose, with its excellent mechanical properties and low weight, would be highly advantageous to employ in bioplastics and biocomposites applications. However, to expand the utilization of cellulose beyond its traditional uses, a modification of the fiber surface is often a prerequisite. One approach is to graft polymer chains on the surface in order to compatibilize the fibers with a non-polar polymer matrix or to introduce functionalities. By exploiting controlled polymerization methods such as ATRP, RAFT, ROP, and ROMP, the surface of the fibers can be carefully tailored. Herein, an overview on controlled, heterogeneous grafting of cellulose fibers and fibrils employing both "grafting from" and "grafting to" methodologies is provided, focusing on the latest findings.

  • 3.
    Engström, Joakim
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Asem, Heba
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Brismar, Hjalmar
    KTH, Centres, Science for Life Laboratory, SciLifeLab. KTH, School of Engineering Sciences (SCI), Applied Physics.
    Zhang, Yuning
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Malkoch, Michael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    In situ encapsulation of Nile red or Doxorubicin during RAFT-mediated emulsion polymerization via polymerization-induced self-assembly for biomedical applications2020In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935Article in journal (Refereed)
  • 4.
    Feng, Zhaoxuan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Gruetzmacher, Hansjoerg
    Chiappone, Annalisa
    Sangermano, Marco
    Photocrosslinked Chitosan Hydrogels Reinforced with Chitosan-Derived no-Graphene Oxide2019In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 220, no 13, article id 1900174Article in journal (Refereed)
    Abstract [en]

    Chitosan and chitosan-derived nano-graphene oxide carbon dots are successfully methacrylated and utilized for the fabrication of photocurable hydrogels. The addition of the nano-graphene oxide (nGO) does not significantly delay the polymer network build-up, but significantly reduces the storage modulus of the crosslinked network, with important detrimental effects on the mechanical performance. By replacing nGO with methacrylated M-nGO, the mechanical performance of the crosslinked polymer network is improved with an increase of the storage modulus as a function of increasing the M-nGO content in the photocurable formulation.

  • 5.
    Finnveden, Maja
    et al.
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Nameer, Samer
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Johansson, Mats K G
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Martinelle, Mats
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    One-Component Thiol-Alkene Functional Oligoester Resins Utilizing Lipase Catalysis2016In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935Article in journal (Refereed)
    Abstract [en]

    Chemo-enzymatic methods are powerful tools for the synthesis of novel materials. By combining the flexibility of chemical synthesis and the high selectivity of enzymes, a variety of functional materials can be achieved. In the present study, a series of α,ω-thiol telechelic oligoesters with varying amount of internal alkenes are prepared using selective lipase catalysis and are subsequently cross-linked by thiol-ene chemistry yielding alkene functional networks. Due to the reactivity of thiols and alkenes almost all present thiol-ene systems consist of two components. This work demonstrates that selective lipase catalysis in combination with renewable monomers with internal alkenes is a promising system for achieving one-component thiol-alkene functional resins with good storage stability and a high degree of thiol end-groups. The developed chemo-enzymatic route yields polymer networks with tailored amount of alkene functionalities in the final thermoset, which facilitate further postmodification.

  • 6.
    Hakkarainen, Minna
    et al.
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    Albertsson, Ann-Christine
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    Heterogeneous biodegradation of polycaprolactone - Low molecular weight products and surface changes2002In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 203, no 11-okt, p. 1357-1363Article in journal (Refereed)
    Abstract [en]

    Gas chromatography-mass spectrometry (GC-MS) analysis showed that caprolactone, 6-hydroxyhexanoic acid, cyclic dimer and cyclic trimer were rapidly assimilated from the surface of polycaprolactone (PCL) films aged in mineral medium inoculated with a mixed culture of compost microorganisms. The degradation in biotic medium proceeded heterogeneously and scanning electron micrographs revealed the formation of parallel grooves, spherical and non-spherical holes in the films. The parallel grooves seen in the scanning electron micrographs after 14 d suggest that the degradation starts preferentially at the amorphous regions. At longer time scales, even the crystalline regions are degraded producing large spherical and non-spherical holes. Comparison of the degradation of melt-pressed and film-blown films made from the same PCL granules in different biotic and abiotic environments showed that both the type of microorganism used and the initial morphology of the films influence the surface erosion pattern and biodegradation mechanism. Rapid degradation and molecular weight decrease required the combined effect of temperature and microorganisms obtained during a biodegradation process, such as composting.

  • 7.
    Lobov, Gleb S.
    et al.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Zhao, Yichen
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Marinins, Aleksandrs
    Yan, Min
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Li, Jiantong
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Sugunan, Abhilash
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Thylen, Lars
    KTH, School of Biotechnology (BIO).
    Wosinski, Lech
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Ostling, Mikael
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics.
    Popov, Sergei
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO.
    Size Impact of Ordered P3HT Nanofibers on Optical Anisotropy2016In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 217, no 9, p. 1089-1095Article in journal (Refereed)
    Abstract [en]

    Poly-3-hexylthiophene (P3HT) nanofibers are 1D crystalline structures with semiconductor properties. When P3HT nanofi bers are dispersed in nonconducting solvent, they react to external alternate electric field by aligning along the field lines. This can be used to create layers of ordered nanofi bers and is referred to as alternating current poling method. P3HT nanofi bers with three different size distributions are fabricated, using self-assembly mechanism in marginal solvents, and used for the alignment studies. Anisotropic absorption of oriented 2 mu m long nanofi bers exponentially increases with the magnitude of applied field to a certain asymptotic limit at 0.8 V mu m(-1), while 100-500 nm long nanofi bers respond to electric field negligibly. Effective optical birefringence of oriented 2 mu m long nanofi bers is calculated, based on the phase shift at 633 nm and the average layer thickness, to be 0.41. These results combined with further studies on real-time control over orientation of P3HT nanofi bers in liquid solution or host system are promising in terms of exploiting them in electroabsorptive and electrorefractive applications.

  • 8.
    Löwenhielm, Peter
    et al.
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Claesson, Hans
    KTH, Superseded Departments, Fibre and Polymer Technology.
    Hult, Anders
    KTH, Superseded Departments, Polymer Technology.
    Poly (neopentylene carbonate) hyperstars2004In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 205, no 11, p. 1489-1496Article in journal (Refereed)
    Abstract [en]

    Branched aliphatic polycarbonates were synthesized by ring opening polymerization of 5,5-dimethyl-1,2-dioxane-2-one (NPC) initiated from polyfunctional alcohols and a commercial hyperbranched polyester (BOLTORN(R)). Polymerizations in the presence of fumaric acid under bulk conditions allowed high conversion (80%) without gelation. The synthesis of polymers with long chain branches was confirmed by size exclusion chromatography and universal calibration. The Mark-Houwink exponent decreased, indicating an increased density, while increasing the number of arms. The star polymers with up to four arms showed thermal properties T-g (20-30degreesC) and T-m (100-110degreesC) similar to linear PNPC.

  • 9.
    Malmstrom, E
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Johansson, M
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Hult, A
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    The effect of terminal alkyl chains on hyperbranched polyesters based on 2,2-bis(hydroxymethyl)propionic acid1996In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 197, p. 3199-3207Article in journal (Refereed)
    Abstract [en]

    A hyperbranched hydroxyfunctional polyester based on 2,2-bis(hydroxymethyl)propionic acid as AB(2)-monomer and a tetrafunctional polyol as core was end-capped with five different alkylacyl chlorides. Alkyl chain lengths ranging from three to sixteen carbons were used. Short alkyl chains (3-6 carbons) decrease the glass transition temperature from around 30 degrees C for the hydroxyterminated polyester to temperatures well below zero. With a sufficiently long alkyl chain (12-16 carbons) the polymers tend to crystallize. The polyesters with C-16-chains as terminal groups exhibit several different crystalline phases as revealed by differential scanning calorimetry. From X-ray data it was possible to suggest that the crystallization for the C-16-terminated samples occurs in a non-interpenetrating fashion for the larger sample and in an interpenetrating way for the smaller polymers.

  • 10. Ranucci, E.
    et al.
    Tarabic, M.
    Gilberti, M.
    Albertsson, Ann-Christine
    KTH, Superseded Departments, Polymer Technology.
    New ester and lactone end-functionalized N-vinyl-2-pyrrolidinone oligomers2000In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 201, no 12, p. 1219-1225Article in journal (Refereed)
    Abstract [en]

    New oligomers of N-vinyl-2-pyrrolidinone functionalized at one end with either ester or lactone functions were obtained by radical polymerization in the presence of different ester (methyl isobutyrate and methyl phenylacetate) and lactone (epsilon-caprolactone, delta-valerolactone and gamma-btyrolactone) compounds as chain transfer agents. The oligomeric samples obtained were characterized in terms of molecular weight and molecular weight distribution by means of analytical size exclusion chromatography (SEC), using purposely synthesized poly(N-vinyl-2-pyrrolidinone) standards. The chain transfer constant C-tau of either methyl isobutyrate, delta-valerolactone, or gamma-butyrolactone towards N-vinyl-2-pyrrolidinone were determined with the help of the known cumulative number-average degree of polymerization (X) over bar(n) and monomer conversion Y-t of the samples during the reaction.

  • 11. Tahir, M. Nazir
    et al.
    Bork, Christian
    Risberg, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Horst, Jennifer C.
    Komoss, Christina
    Vollmer, Antje
    Mischnick, Petra
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Alkynyl Ethers of Glucans: Substituent Distribution in Propargyl-, Pentynyl- and Hexynyldextrans and -amyloses and Support for Silver Nanoparticle Formation2010In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 211, no 15, p. 1648-1662Article in journal (Refereed)
    Abstract [en]

    Alkynyldextrans with a DS in the range 0.1-1.67 have been prepared as reactive intermediates for further polymer-analogous functionalisation.. DS and substituent distribution were determined by GLC and GLCMS after hydrolysis and acetylation, or methanolysis and trimethylsilylation. Reactivity was in the order O-2 > O-4 >= O-3 with pronounced differences in the distinct patterns for propargyl ethers and its higher homologous. A large deviation from a random substituent distribution was observed. Propargyldextrans were not stable during long-time storage in the solid state, while terminal pentynyl and hexynyl ethers are. Pentynyldextrans showed structure formation of various geometries. They bound silver efficiently, yielding silver nanoparticles by reduction.

  • 12.
    Torron, Susana
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Semlitsch, Stefan
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Martinelle, Mats
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Johansson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Polymer Thermosets from Multifunctional Polyester Resins Based on Renewable Monomers2014In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 215, no 22, p. 2198-2206Article in journal (Refereed)
    Abstract [en]

    The use of monomers based on natural materials as a future supply of raw materials has gained more interest in the last decade. Sources ranging from wood to plant oils and algae are exploited as alternatives to traditional fossil-based resources for the synthesis of polymeric materials. The use of these raw materials is not only of interest because of its abundance, but also in terms of price, durability, and/or biodegradability. In the present study, a series of resins utilizing a monomer derived from birch bark is prepared. The thermoset resins are formed by reacting an epoxy-functional omega-hydroxy fatty acid with methacrylate monomers using enzyme catalysis to form multifunctional resins via a one-pot synthesis. The derived oligomers are crosslinked through different polymerization routes to produce thermosets with different properties and/or functionalities. This approach allows natural-based resins with tuned functionalities and mechanical and thermal properties to be obtained.

  • 13.
    Ture, Hasan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Blomfeldt, Tomas O. J.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Gällstedt, Mikael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Hedenqvist, Mikael S.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymeric Materials.
    Farris, Stefano
    University of Milan.
    Nanostructured Silica Wheat Gluten Hybrid Materials Prepared by Catalytic Sol-Gel Chemistry2013In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 214, no 10, p. 1131-1139Article in journal (Refereed)
    Abstract [en]

    The main physicochemical properties of nanostructured silica/wheat gluten hybrid composites are presented. The extraction experiments suggest that the protein phase is intimately encased within the silica matrix, with silica–protein interactions driven by hydrogen bonding, as indicated by IR spectra. Spectroscopic results also show that silica induces a higher degree of constraint of the wheat gluten matrix, despite less aggregation. Moisture diffusion properties of the hybrid materials are investigated by a combined “desorption/sorption” approach. While the reduction of the moisture diffusivity in the presence of silica can be described by the geometrical impedance of a “sintered” porous solid, a time-dependent relaxation/restructuring of the composite apparently occurs during the sorption-desorption cycle.

  • 14. Uppalapati, Suji
    et al.
    Chada, Sailaja
    Engelhard, Mark H.
    Yan, Mingdi
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Photochemical Reactions of Poly(4-vinylphenol) Thin Films2010In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 211, no 4, p. 461-470Article in journal (Refereed)
    Abstract [en]

    The mechanism involved in the photochemical immobilization of poly (4-vinylphenol) (PVP) thin. films was investigated. The films were fabricated by a simple procedure of UV irradiation and solvent extraction. A combination of ellipsometry, IR, and high-resolution X-ray photoelectron spectroscopy (XPS) was used to provide detailed and quantitative analysis of the composition of the photochemical reaction products. Upon irradiation at 260 nm, benzyl and phenoxy radicals are generated in the polymer. In the absence of oxygen, PVP films crosslinked via the combination of the benzyl radicals or phenoxy radicals. At lower irradiation doses, the photochemical process was dominated by cross-linking of the polymer backbone via the combination of benzyl radicals. At higher exposure doses, cross-linked quinoid structures were generated, and the concentration increased with the irradiation time. No oxidation or degradation products were observed. In the presence of oxygen, additional reactions of oxidation and degradation occurred. At lower doses, oxidation at the benzyl position produced the ketone structure evidenced by the drastic increase in the 0 content in the irradiated films. As the irradiation doses increased, further oxidation at the methylene position occurred, and in addition, volatile and degradation products were also generated. This photochemical process was successfully employed to fabricate patterned PVP structures.

  • 15.
    Xu, Huan
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hua, Geng
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Odelius, Karin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Stereocontrolled Entanglement-Directed Self-Alignment of Poly(lactic acid) Cylindrites2016In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935Article in journal (Refereed)
    Abstract [en]

    The concept of stereocontrolled entanglements, in which the tunable H-bonded chiral pairs serve as crosslinks to create topological constraints on the local chain dynamics, is introduced to tailor the crystalline morphology of stereocomplex poly(lactic acid). For the entanglements to be interconnected and activated, poly(d-lactic acid) with statistical branched architecture is incorporated, enabling the construction of 3D association with linear poly(l-lactic acid) chains. With thermodynamically graded disentanglement relaxation for the blends, the profound influence of entanglements on the crystalline morphology is revealed during isothermal crystallization. Orderly aligned cylindrites some with an exceptional length of over 500 μm, resembling the structural features of the classical shish-kebab superstructure, are observed in the blends penetrated with dense entanglement constraints. By contrast, only dendritic spherulites are formed in the highly disentangled blends. The selectively suppressed homo-crystallization by the entanglements offers insights into the contribution of constraints. This bottom-up strategy opens up pathways to engender oriented crystals of long-range order under quiescent conditions, which has potential implications for other chiral polymers.

  • 16.
    Yushmanov, Pavel
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Industrial NMR Centre.
    Furó, István
    KTH, School of Chemical Science and Engineering (CHE), Centres, Industrial NMR Centre.
    Iliopoulos, Ilias
    Kinetics of demixing and remixing transitions in aqueous solutions of poly(N-isopropylacrylamide):  A temperature-jump H-1 NMR study2006In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 207, no 21, p. 1972-1979Article in journal (Refereed)
    Abstract [en]

    The time course of the coil-to-globule collapse and intermolecular aggregation of poly(N-isopropylacrylamide) in aqueous solution upon exceeding the lower critical solution temperature (LCST) are investigated by temperature-jump 1H NMR spectroscopy. After the temperature jump, we record the time dependences of (i) the mobile fraction of the polymer chain as revealed by the intensity of the liquid-like NMR signal, (ii) the local mobility of those chains as revealed by the transverse relaxation time T2, and (iii) their self-diffusion coefficient D. The same data are also reported at their temperature-dependent long-time limits. The results suggest a sudden, faster than one second, collapse and intermolecular aggregation into globules and a slower reorganization/redistribution of the individual chains among and within the globular and mobile states. We found that all molecular changes are reversible if the temperature remains less than ca. 6-8 K above the LCST for less than a few minutes; under those conditions, experiments upon sudden temperature quench below the LCST show that the aggregates disintegrate and swell into coils in less than a few seconds.

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