One-Pot Freezing-Thawing Preparation of Multifunctional Cellulose Nanocrystals/Poly(vinyl alcohol) Ionic Organohydrogel

Abstract

Cellulose nanocrystals were extracted by the method of acid hydrolysis of microcrystalline cellulose, and a simple one-pot method of dissolving polyvinyl alcohol and cellulose nanocrystals in dimethyl sulfoxide/water is proposed to prepare ionic conductive organohydrogels. Transmission electron microscope, ultraviolet-visible spectrophotometer, X-ray diffraction, Fourier transform infrared spectroscopy, universal material testing machine, electrochemical workstation, and the LCR digital bridge tester were used to study the microscopic morphology, light trans-mission properties, mechanical performance, electrical properties and sensing properties of the organohydrogel. The results show that the ionic conductive organohydrogels exhibit high stretchability (377% strain), firmness (strain at break to 345.51 kPa), good transparency and high gauge factor 4.63 (0–400% strain). The tensile fracture test shows that the organohydrogel has good toughness and elasticity in terms of tensile strength and toughness. Moreover, the PVA/CNC organohydrogels were used as the conductive medium to form a self-powered strain sensor and wearable strain sensor, and the open-circuit voltage of the self-powered system could reach 0.859 V, indicating that the organohydrogel has good electrical conductivity and sensor’s stability.