Synergistic effect of hydrophilic palygorskite and hydrophobic zein particles on the properties of chitosan films

Chitosan (CS) with unique properties can interact with hydrophilic nanoclay and hydrophobic plant protein particles. In this study, we designed a CS matrix using hydrophilic palygorskite (PAL) nanoclay and hydrophobic zein particles (ZPs) as combined fillers for reinforcement. CS-PAL-ZP ternary composites were prepared using solution casting method, and the synergistic reinforcing role of PAL and ZP on the properties of CS matrix was studied. Homogenous dispersion of the combined nanofillers in the CS matrix resulted in a remarkable enhancement in tensile strength, water resistance and surface hydrophobicity at low loadings. In addition, the tensile strength and surface hydrophobicity of CS-PAL-ZP ternary composites were higher than those of CS-PAL or CS-zein composites with the same amounts of individual filler. These results clearly confirmed the synergistic reinforcement of hydrophilic PAL and hydrophobic ZP in improving the various properties of CS-based composite. Therefore, this approach would provide an effective method for designing and fabricating ternary composites based on amphiphilic polymer matrix and hydrophilic-hydrophobic fillers with improved properties for extending their applications. (C) 2019 The Authors. Published by Elsevier Ltd.