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- Apostolopoulou Kalkavoura, Varvara, 1988-, et al.
(författare)
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In Situ Functionalisation and Upcycling of Post-Consumer Textile Blends into 3D Printable Nanocomposite Filaments
- 2024
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Ingår i: Advanced Sustainable Systems. - 2366-7486 .- 2366-7486.
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Tidskriftsartikel (refereegranskat)abstract
- The linear lifecycle of the textile industry contributes to the enormous waste generation of post-consumer garments. Recycling or repurposing of post-consumer garments typically requires separation of the individual components. This study describes a novel and facile chemo-thermo-mechanical method for producing extrudable pellets, involving one-pot, 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation of post-consumer polycotton textiles, followed by mild mechanical treatment, all without isolating the constituents of the polycotton blend. The oxidized blend with high cellulose and carboxylate content of 1221 ± 82 mmol COO− per kg of cotton, is pelletised into a masterbatch and further in situ extruded into nanocomposite filaments for 3D printing. The carboxyl groups introduced on the polycotton-based filters enable cotton fibrillation into nanoscaled fibers during mechanical treatment and extrusion resulting to a variety of functional and high surface-finish quality models, including filters and fashion accessories. The electrostatic interactions with positively charged species, such as methylene blue (MB), facilitate their adsorption from water while exhibiting promising adsorption capacities. The adsorption of MB follows the Freundlich model and depends on the printed porosity of the filter. A “trash to treasure” concept for textile waste is further corroborated through the use of the developed 3D printing filament into commodity products.
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| 2. |
- Grachev, Vladimir, et al.
(författare)
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Thermodynamics of interactions between cellulose nanocrystals and monovalent counterions
- 2024
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Ingår i: Carbohydrate Polymers. - 0144-8617 .- 1879-1344. ; 333
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Tidskriftsartikel (refereegranskat)abstract
- Alkali and quaternary ammonium cations interact with negatively charged cellulose nanocrystals (CNCs) bearing sulfated or carboxylated functional groups. As these are some of the most commonly occurring cations CNC encounter in applications, the thermodynamic parameters of these CNC-counterion interactions were evaluated with isothermal titration calorimetry (ITC). Whereas the adsorption of monovalent counterions onto CNCs was thermodynamically favourable at all evaluated conditions as indicated by a negative Gibbs free energy, the enthalpic and entropic contributions to the CNC-ion interactions were found to be strongly dependent on the hydration characteristics of the counterion and could be correlated with the potential barrier to water exchange of the respective ions. The adsorption of chaotropic cations onto the surface was exothermic, while the interactions with kosmotropic cations were endothermic and completely entropy-driven. The interactions of CNCs with more bulky quaternary ammonium counterions were more complex, and the mechanism of interaction shifted from electrostatic interactions with surface charged groups of CNCs towards adsorption of alkyl chains onto the CNC hydrophobic planes when the alkyl chain length increased.
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| 3. |
- Khalili, Houssine, 1998-, et al.
(författare)
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Nanocellulose-Bovine Serum Albumin Interactions in an Aqueous Medium : Investigations Using In Situ Nanocolloidal Probe Microscopy and Reactive Molecular Dynamics Simulations
- 2024
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Ingår i: Biomacromolecules. - 1525-7797 .- 1526-4602. ; 25:6, s. 3703-3714
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Tidskriftsartikel (refereegranskat)abstract
- As a versatile nanomaterial derived from renewable sources, nanocellulose has attracted considerable attention for its potential applications in various sectors, especially those focused on water treatment and remediation. Here, we have combined atomic force microscopy (AFM) and reactive molecular dynamics (RMD) simulations to characterize the interactions between cellulose nanofibers modified with carboxylate or phosphate groups and the protein foulant model bovine serum albumin (BSA) at pH 3.92, which is close to the isoelectric point of BSA. Colloidal probes were prepared by modification of the AFM probes with the nanofibers, and the nanofiber coating on the AFM tip was for the first time confirmed through fluorescence labeling and confocal optical sectioning. We have found that the wet-state normalized adhesion force is approximately 17.87 +/- 8.58 pN/nm for the carboxylated cellulose nanofibers (TOCNF) and about 11.70 +/- 2.97 pN/nm for the phosphorylated ones (PCNF) at the studied pH. Moreover, the adsorbed protein partially unfolded at the cellulose interface due to the secondary structure's loss of intramolecular hydrogen bonds. We demonstrate that nanocellulose colloidal probes can be used as a sensitive tool to reveal interactions with BSA at nano and molecular scales and under in situ conditions. RMD simulations helped to gain a molecular- and atomistic-level understanding of the differences between these findings. In the case of PCNF, partially solvated metal ions, preferentially bound to the phosphates, reduced the direct protein-cellulose connections. This understanding can lead to significant advancements in the development of cellulose-based antifouling surfaces and provide crucial insights for expanding the pH range of use and suggesting appropriate recalibrations.
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