Cellulose gelation in NaOH(aq) by CO2 absorption: Effects of holding time and concentration on biomaterial development

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2023-02-15
Major/Subject
Mcode
Degree programme
Language
en
Pages
8
Series
Carbohydrate Polymers, Volume 302
Abstract
We address the limited solubility and early onset of gelation of aqueous sodium hydroxide to position it as a preferred green solvent for cellulose. For this purpose, we expand the concentration window (up to 12 wt%) by using a CO2-depleted air and adjusting the time the dope remains in the given atmosphere, before further processing (holding time) and regeneration conditions. Cellulose solutions are extruded following characteristic (rheology and extrusion) parameters to yield aligned filaments reaching tenacities up to 2.3 cN·dtex−1, similar to that of viscose. Further material demonstrations are achieved by direct ink writing of auxetic biomedical meshes (Poisson's ratio of −0.2, tensile strength of 115 kPa) and transparent films, which achieved a tensile strength and toughness of 47 MPa and 590 kJ·m−3, respectively. The results suggest an excellent outlook for cellulose transformation into bioproducts. Key to this development is the control of the gelation ensuing solution flow and polymer alignment, which depend on CO2 absorption, cellulose concentration, and holding time.
Description
| openaire: EC/H2020/788489/EU//BioELCell Funding Information: GR acknowledges the contribution of UPM and support of the Academy of Finland's Flagship, Competence Center for Materials Bioeconomy, FinnCERES [grant numbers 318890, 318891]. GR, RA, JJK, and OJR are grateful for the support received from the ERC Advanced Grant Agreement No. 788489 (“BioElCell”) and The Canada Excellence Research Chair Program (CERC-2018-00006), as well as Canada Foundation for Innovation (Project number 38623). The provision of facilities and technical support by Aalto University at OtaNano - Nanomicroscopy Center (Aalto-NMC) is also gratefully acknowledged. Publisher Copyright: © 2022 The Author(s)
Keywords
Additive manufacturing, Alkali cellulose, Cellulose rheology, Cellulose spinning, Cellulose textiles, CO absorption, CO capture
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Citation
Reyes, G, Ajdary, R, Kankuri, E, Kaschuk, J J, Kosonen, H & Rojas, O J 2023, ' Cellulose gelation in NaOH (aq) by CO 2 absorption: Effects of holding time and concentration on biomaterial development ', Carbohydrate Polymers, vol. 302, 120355 . https://doi.org/10.1016/j.carbpol.2022.120355