Preparation and characteristics of nanosilver composite based on chitosan-graft-acrylic acid copolymer

Abstract

The aim of this work was to prepare and characterize the novel antibacterial nanocomposites based on chitosan, grafted acrylic acid and silver nanoparticles (AgNPs). Chitosan has been functionalised by chemical reaction with acrylic acid, and then mixed with silver nanoparticles (AgNPs). AgNPs have been obtained formerly by chemical reduction of silver nitrate in the presence of mercaptosuccinic acid as a nanoparticles stabilizer. Structure and properties of obtained nanocomposite have been characterised by UV–vis, FTIR and 13C-NMR spectroscopy. The morphology of silver chitosan-g-acrylic acid nanocomposite has been studied by electron microscopy (SEM/EDX and HR-TEM). Thermal stability has been investigated by thermogravimetric analysis. The grafted chitosan contained 70.9 % wt acrylic acid, as determined by gravimetric method. It was found that modified chitosan forms water-insoluble gel with lower thermal resistance than pure chitosan. However, the difference between thermal properties of grafted chitosan and its nanocomposite with AgNPs is negligible. The grafting reaction mechanism has been discussed in detail on the basis of the obtained results and current literature data.