Relationship between production condition, microstructure and final properties of chitosan/graphene oxide–zinc oxide bionanocomposite

Herein, chitosan–graphene oxide–zinc oxide nanocomposites were produced using two different methods (in situ preparation using single step and solution mixing) at different loading level and the effect of production process and filler content on the chemical structure, morphology, mechanical, dynamic mechanical and thermal stability were studied by FTIR, SEM, XRD, tensile, DMTA and TGA analysis. FTIR results showed that chitosan extracted from chitin and ZnO formed during single step in-site fabrication method simultaneously. Morphological study and tensile test demonstrated that the well dispersion of filler in the chitosan during single step preparation as a result of interfacial interaction between functionalized groups of GO and chitosan lead to enhancement of tensile properties in the range of 39% for tensile strength and 71% improvement for Young's modulus at 1 w/w% of filler content. DMTA analysis shows that storage modulus of chitosan nanocomposites significantly enhanced as a result of homogenous dispersed GO and the strong interfacial attraction. TGA analysis confirmed that thermal stability of the chitosan–GO–ZnO prepared via single step is higher due to the better dispersion of GO–ZnO in the chitosan.