Strength and Water Interactions of Cellulose I Filaments Wet-Spun from Cellulose Nanofibril Hydrogels

Abstract

Hydrogels comprising cellulose nanofibrils (CNF) were used in the synthesis of continuous filaments via wet-spinning. Hydrogel viscosity and spinnability, as well as orientation and strength of the spun filaments, were found to be strongly affected by the osmotic pressure as determined by CNF surface charge and solid fraction in the spinning dope. The tensile strength, Young’s modulus and degree of orientation (wide-angle X-ray scattering, WAXS) of filaments produced without drawing were 297 MPa, 21 GPa and 83%, respectively, which are remarkable values. A thorough investigation of the interactions with water using dynamic vapour sorption (DVS) experiments revealed the role of sorption sites in the stability of the filaments in wet conditions. DVS analysis during cycles of relative humidity (RH) between 0 and 95% revealed major differences in water uptake by the filaments spun from hydrogels of different charge density (CNF and TEMPO-oxidised CNF). It is concluded that the mechanical performance of filaments in the presence of water deteriorates drastically by the same factors that facilitate fibril alignment and, consequently, enhance dry strength. For the most oriented filaments, the maximum water vapour sorption at 95% RH was 39% based on dry weight.

Nanocellulose in Thin Films, Coatings, and Plies for Packaging Applications: A Review

“…Cellulosic materials are inherently sensitive to the presence of both gaseous and liquid water (Spence et al 2010a(Spence et al ,b, 2011a Belbekhouche et al 2011; Ferrer et al 2012a,b;Abdollahi et al 2013a; Bai et al 2015;Ferrer et al 2015Ferrer et al , 2016bRojo et al 2015;Lundahl et al 2016). There also have been efforts to modify nanocellulose-based systems so as to improve barrier performance in key areas.…”

Interfacial Polyelectrolyte Complex Spinning of Cellulose Nanofibrils for Advanced Bicomponent Fibers

“…Fibers based on CNF or TOCN have aroused particular interest in the nanocellulose research community, due to the inherent suitability of cellulose to form strong fibers. [15][16][17][18][19][20][21][22] Especially, wet-spinning of CNF into a nonsolvent (i.e. coagulation bath such as ethanol or acetone) has been widely explored and exploited.…”

Particle image diffusometry: Resolving diffusion coefficient field from microscopy movie data without particle tracking

“…Therefore, rheological behaviors of CNFs have been actively discussed until today. [23][24][25][26] We prepared the sample dispersions in the domain with a thickness of 100 µm using a silicone sheet as a spacer and sealed with cover glasses on top and bottom sides as shown in Fig. 1.…”