TY - JOUR
T1 - Cellulose gelation in NaOH(aq) by CO2 absorption
T2 - Effects of holding time and concentration on biomaterial development
AU - Reyes, Guillermo
AU - Ajdary, Rubina
AU - Kankuri, Esko
AU - Kaschuk, Joice J.
AU - Kosonen, Harri
AU - Rojas, Orlando J.
N1 - Publisher Copyright:
© 2022 The Author(s)
PY - 2023/2/15
Y1 - 2023/2/15
N2 - 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.
AB - 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.
KW - Additive manufacturing
KW - Alkali cellulose
KW - Cellulose rheology
KW - Cellulose spinning
KW - Cellulose textiles
KW - CO absorption
KW - CO capture
UR - http://www.scopus.com/inward/record.url?scp=85142746931&partnerID=8YFLogxK
U2 - 10.1016/j.carbpol.2022.120355
DO - 10.1016/j.carbpol.2022.120355
M3 - Article
C2 - 36604045
AN - SCOPUS:85142746931
SN - 0144-8617
VL - 302
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
M1 - 120355
ER -
