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- Jönsson, Christina, et al.
(författare)
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Biocatalysis in the Recycling Landscape for Synthetic Polymers and Plastics towards Circular Textiles
- 2021
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Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 14:19, s. 4028-4040
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Tidskriftsartikel (refereegranskat)abstract
- Although recovery of fibers from used textiles with retained material quality is desired, separation of individual components from polymer blends used in today's complex textile materials is currently not available at viable scale. Biotechnology could provide a solution to this pressing problem by enabling selective depolymerization of recyclable fibers of natural and synthetic origin, to isolate constituents or even recover monomers. We compiled experimental data for biocatalytic polymer degradation with a focus on synthetic polymers with hydrolysable links and calculated conversion rates to explore this path The analysis emphasizes that we urgently need major research efforts: beyond cellulose-based fibers, biotechnological-assisted depolymerization of plastics so far only works for polyethylene terephthalate, with degradation of a few other relevant synthetic polymer chains being reported. In contrast, by analyzing market data and emerging trends for synthetic fibers in the textile industry, in combination with numbers from used garment collection and sorting plants, it was shown that the use of difficult-to-recycle blended materials is rapidly growing. If the lack of recycling technology and production trend for fiber blends remains, a volume of more than 3400 Mt of waste will have been accumulated by 2030. This work highlights the urgent need to transform the textile industry from a biocatalytic perspective.
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| 2. |
- Schönhoff, M, et al.
(författare)
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Dynamics in polymer layers investigated by NMR techniques
- 2002
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Ingår i: Progress in Colloid and Polymer Science. - 0340-255X .- 1437-8027. ; 121, s. 80-87
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Tidskriftsartikel (refereegranskat)abstract
- A large number of different NMR methods are of great usefulness in the investigation of molecular mobility in organic bulk systems, while studies at interfaces are rare owing to the low intrinsic sensitivity of NMR methods. This article presents two examples of the application of spin resonance in investigations of polymers at interfaces, employing polymer-coated colloids: Applying 1H liquid-state NMR to monitor segmental mobility, the phase transition of the thermoreversible polymer poly(N-isopropylacrylamide) is investigated in the restricted geometry of an adsorption layer, and furthermore under the influence of charges in a statistical copolymer. The phase transition is substantially broader than in solution and for the charged copolymer, mobile segments remain even above the transition temperature. This is attributed to a comparatively mobile arrangement of the copolymer layer. Owing to the electrostatic repulsion from the surface, the copolymer layer is confined to a configuration with charged loops extending further from the interface. The second example concerns polyelectrolyte multilayers formed by self-assembly of polyanions and polycations onto colloidal particles. The hydration of the layer system is studied using 1H spin-relaxation rates, R2, of water, which are a measure for the immobilisation of water molecules in the multilayers. A linear increase in R2 with the number of layers is found for [poly(sodium 4-styrenesulfate)/poly(diallyl dimethyl ammonium chloride)]N, reflecting a constant increase in the amount of hydration water with the adsorption of each layer. For [poly(sodium 4-styrenesulfate)/poly(allylamine hydrochloride)]N, involving a weak polyelectrolyte, the data show reversible swelling behaviour with respect to the electric potential of the outer layer: A positive surface charge leads to a swelling of the multilayers, while owing to a negative surface charge deswelling occurs
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