Regioselective and water-assisted surface esterification of never-dried cellulose: nanofibers with adjustable surface energy†
| Autor: | Orlando J. Rojas, Caio G. Otoni, Bin Zhao, Roozbeh Abidnejad, Bruno D. Mattos, Marco Beaumont, Tetyana V. Koso, Alistair W. T. King, Anett Kondor |
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| Přispěvatelé: | Department of Chemistry, Department of Bioproducts and Biosystems, Universidade Federal de São Carlos, Bio-based Colloids and Materials, University of Helsinki, Surface Measurement Systems Ltd, Aalto-yliopisto, Aalto University |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
SELECTION
ACETYLATION SUSPENSIONS 116 Chemical sciences MOISTURE SORPTION 02 engineering and technology Reactive extrusion 010402 general chemistry WOOD OXIDATION 01 natural sciences Acylation chemistry.chemical_compound Environmental Chemistry Cellulose MICROFIBRILS BINDING PROPERTIES 021001 nanoscience & nanotechnology Pollution Pickering emulsion Surface energy 0104 chemical sciences 3. Good health Chemistry chemistry Chemical engineering Nanofiber Surface modification 0210 nano-technology Selectivity FIBERS |
| Zdroj: | Green Chemistry Beaumont, M, Otoni, C G, Mattos, B D, Koso, T V, Abidnejad, R, Zhao, B, Kondor, A, King, A W T & Rojas, O J 2021, ' Regioselective and water-assisted surface esterification of never-dried cellulose : nanofibers with adjustable surface energy ', Green Chemistry, vol. 23, no. 18, pp. 6966-6974 . https://doi.org/10.1039/d1gc02292j |
| ISSN: | 1463-9262 |
| Popis: | A new regioselective route is introduced for surface modification of biological colloids in the presence of water. Taking the case of cellulose nanofibers (CNFs), we demonstrate a site-specific (93% selective) reaction between the primary surface hydroxyl groups (C6-OH) of cellulose and acyl imidazoles. CNFs bearing C6-acetyl and C6-isobutyryl groups, with a degree of substitution of up to 1 mmol g−1 are obtained upon surface esterification, affording CNFs of adjustable surface energy. The morphological and structural features of the nanofibers remain largely unaffected, but the regioselective surface reactions enable tailoring of their interfacial interactions, as demonstrated in oil/water Pickering emulsions. Our method precludes the need for drying or exchange with organic solvents for surface esterification, otherwise needed in the synthesis of esterified colloids and polysaccharides. Moreover, the method is well suited for application at high-solid content, opening the possibility for implementation in reactive extrusion and compounding. The proposed acylation is introduced as a sustainable approach that benefits from the presence of water and affords a high chemical substitution selectivity. We report a versatile and simple preparation of hydrophobic cellulose nanofibers through a spatially confined modification of the primary surface hydroxyl groups. |
| Databáze: | OpenAIRE |
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