Nonsolvent-Induced Phase Separation-Jet Spinning: An Innovative Technique for Producing Cellulosic Nanofilms,
De Nguyen1, Kenji Kinashi2, Yukihiro Nishikawa3
1Doctor's Program of Materials Chemistry, Graduate School of Science and Technology, Kyoto Institute of Technology, Matsugasaki, Sakyo, Kyoto 606-8585, Japan.
Abstract:
The development of biobased porous materials using straightforward procedures remains challenging. This study introduces nonsolvent-induced phase separation-jet spinning (NIPS-JS), an innovative technique for fabricating cellulose acetate nanofilms. Coupling nonsolvent-induced phase separation (NIPS) with the turbulent mixing effects of high-velocity coaxial jets, NIPS-JS, achieves rapid and efficient nanofilm formation (40-50 nm thickness), demonstrating production rates exceeding 0.8 g·min-1 and possessing adjustable parameters for optimization. The NIPS-JS technique holds promise for processing of diverse polymeric materials undergoing NIPS. Furthermore, this study demonstrates a novel application of NIPS-JS films for fabricating ultralight cellulosic sponges using cryo-templating and lyophilization, reducing the use of organic solvents and chemical cross-linkers. The resulting monolithic, three-dimensional networks, stabilized by robust lamination of individual thin films, exhibit ultralow density (5-10 kg·m-3), high porosity (>99%), and excellent stability. Notably, the addition of 0.2-1 wt % ethanol enhances the reproducibility of the cryo-templating step and minimizes shrinkage. This cost-effective and scalable approach offers a promising pathway for the production of innovative porous materials without chemical cross-linkers.
