Mechanical and Morphological Studies of Chitosan/Clay Composites

In the present paper, the results of mechanical properties and atomic force microscopy studies of chitosan (Ch) with montmorillonite (MMT) or nano-clay are presented. The blends composed of chitosan (Ch) with montmorillonite (MMT) have been prepared as material designed for cosmetic industries and/or biomedical applications. Mechanical properties such as the ultimate tensile strength, percentage elongation and Young's modulus of films have been determined and compared. Addition of nanoclay after surface modification improved the mechanical properties more than montmorillonite without modification. The surface properties of the chitosan and montmorillonite films and their composites have been studied by tapping-mode atomic force microscopy (AFM). The changes of topography images were considered by determining the root mean square (Rms) deviation in the image data. AFM images show differences in surface properties of chitosan films, chitosan/MMT films, and chitosan/nanoclay films. Surface roughness decreased with addition of MMT and/or nanoclay into chitosan matrix. The obtained results suggest that the properties of chitosan and montmorillonite composites depend on the blend composition and on the way of surface modification of nano-clay.