The effect of ZnO addition against crystallinity and water absorption capacity of biofoam based cassava starch reinforced bacterial cellulose

Abstract

Polystyrene is one type of plastic that is hard to be degraded, because of that, it requires an alternative to reduce polystyrene waste through biofoam. Biofoam which is made of starch is reinforced with bacterial cellulose that has high hydrophilic properties. This study aims to know the effect of ZnO addition to crystallinity and water absorption capacity of biofoam based cassava starch reinforced bacterial cellulose. The method used experimental design. Synthesis of biofoam was conducted using baking process method with varied the ZnO content in the biofoam were 0%, 3%, 6%, 9%. The resulted samples were analyzed by X-ray diffraction and water absorption test to determine the effect of ZnO concentration. The results showed that the addition of ZnO variation into biofoam caused the change in diffraction position and intensity. The control variation (0% ZnO) had the highest diffraction peak at the position of 20.88°2θ with an intensity of 68.65 counts, crystallite size of 20.795 nm. After adding ZnO variation of 3%, 6%, 9%, diffraction position and intensity change to be 36.31°2θ and 276.29 counts, 36.26°2θ and 558.81 counts, and 36.31°2θ and 725.78 counts, respectively. The addition of ZnO into biofoam composite decreased water absorption up to 33% compared than the control sample, and the lowest optimum absorption resulted in ZnO concentration of 9% with water absorption value of 0.164 (gH2O/g).