Preparação e caracterização de nanocompósitos quitosana/bentonita.

Abstract

Chitosan can be modified and intercalated layered silicate through cation exchange reaction, resulting in nanocomposites with interesting structural and functional properties. In this study, nanocomposites of chitosan and natural bentonite were prepared by solution intercalation and influence on the amount of bentonite in the morphology, thermal and mechanical properties of the nanocomposites. Films of pure chitosan and chitosan/bentonite prepared in acetic acid solution were characterized by infrared spectroscopy, X-ray diffraction, thermogravimetric and mechanical tests. The morphology of the nanocomposites was affected by the ratio of chitosan / bentonite. Morphology with predominantly intercalated nanocomposites were obtained when the ratio of chitosan and bentonite was 5:1. Moreover, morphologically predominantly exfoliated nanocomposites were obtained when the ratio of chitosan / bentonite ratio was 10:1. Compared with pure chitosan films, thermal stability, mechanical strength and stiffness of the nanocomposite films of chitosan / bentonite were considerably higher. Therefore, natural bentonite can be successfully used in the preparation of nanocomposites based on chitosan nanocomposites and these may in the near future, be applied in various segments, among which, as a system for controlled drug delivery and as a basis for preparing biosensors.