Preparation of highly hazy transparent cellulose film from dissolving pulp

Recently, cellulose films or nanopapers have aroused great attention due to their potential for utilization in photoelectric materials. In this study, transparent cellulose films were prepared from TEMPO-oxidized cellulose fibers by the casting method after they were ultrasonicated to improve the light transmittance and haze. It was found that powerful ultrasonication initiated severe cellulose fiber flattening, fibrillation, and breakage. Therefore, films with compact structures and smooth surfaces could be prepared, resulting in high transparency and tensile strength. However, excessive ultrasonic treatment caused transmittance haze loss. By controlling the ultrasonic power within the range of 180-360 W, transparent films (transmittance of similar to 90%) with 51-76% haze were obtained.