In vitro antimicrobial activity of intercalated Modified Chitosan-Clay nanocomposite against different microorgamnisms

Abstract

Unmodified sodium montmorillonite (Na-MMT) used to intercalate chitosan (CS) and modified chitosan. Their structures were characterized by XRD, TEM and IR techniques. The results showed that CS chains were inserted into silicate layers. The interlayer distance of the layered silicates in the nanocomposites enlarged as the amount of polymer increased. The thermal stability of the nanocomposites are characterized by TGA. In vitro antimicrobial assay showed that pristine montmorillonite could not inhibit the growth of bacteria. Chitosan was less effective in inhibiting bacterial growth than chitosan modified triphenyl phosphine ( mod- CS).  CS/MMT and mod-Cs/MMT nanocomposites had strong antimicrobial activity, particularly against Gram-positive bacteria. With the increase of the amount and the interlayer distance of the layered silicates in the nanocomposites, the nanocomposites showed a stronger antibacterial effect.

Keywords: Chitosan; Nanocomposite; Antimicrobial