Developing a conductive cellulose film without any metal compounds remains challenging, though in great demand. However, cellulose film prepared from bacterial cellulose (BC) powder without any metal compounds has poor tensile, physical, and electrical properties, thus limiting its application. Herein, this study aims to prepare and characterize an all-cellulose film from 2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized bacterial cellulose (TOBC) powders without adding metal compounds and treated by ultrasonication. TOBC powders are sonicated with various powers of 250, 500, and 750 W for 20 min without any other substance. It was proved that increasing the ultrasonication power level resulted in a significant improvement in the properties of the film. The ultrasonication of 750 W increased tensile strength by 85%, toughness by 308%, light transmittance by 542%, and electrical conductivity by 174% compared to the nonsonicated film. A light-emitting diode connected to a power source through this sonicated film was much brighter than that connected via a nonsonicated film. For the first time, this study reports the preparation of electrically conductive, transparent, strong, and bendable pure TOBC films by increasing ultrasonic power for environmentally friendly electronic devices application.
Developing a simple and environmentally friendly method to vary the physical, mechanical, and thermal properties of cellulose films is of great importance. This study aimed to characterize 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized bacterial cellulose (BC) films prepared using non-pressurized hot water vapor (NPHWV) method. A wet BC-pellicle that had been oxidized with TEMPO was treated with NPHWV for 60, 120, and 240 minutes, respectively. As a control, a TEMPO-oxidized BC (TOBC) film without NPHWV was prepared. The results show that the longer NPHWV duration of the TOBC film increased the tensile and thermal properties. This film became more hydrophobic and showed lower moisture absorption, thermal conductivity and organic solvent uptake, more crystalline structure, and higher fiber density after NPHWV treatment. The acquired results provide a simple, inexpensive, and ecologically friendly method for varying TOBC film properties.