Removal of impurities from cellulose films after their regeneration from cellulose dissolved in DMAc/LiCl solvent system

Solvents and ions entrapped in a cellulose matrix during regeneration process have a significant effect on the performance and durability of electroactive paper actuators made using regenerated cellulose. This article describes a simple approach to remove solvents and Li+ ions from the regenerated cellulose films by combining distillation process, washing with isopropyl alcohol (IPA)-deionized (DI) water mixture and running-water technique. It is possible to obtain a good surface morphology and the highest transmittance (90%) as well as a negligible amount of DMAc when films are washed with a DI/IPA mixture ratio equal to 60:40. Li+ ion concentration drastically reduced from 15 380 to 10.61 ppm upon exposure to running water continuously for 24 h. This process enables us to develop e-paper, flexible thin film transistors, IDT, and SAW sensors based on cellulose paper.