Hydrothermal Synthesis and Properties of Chitosan–Silver Nanocomposites

A facile “green chemistry” hydrothermal method of chitosan-Ag nanoparticles (NPs) synthesis has been proposed. Chitosans of different molecular weight (from 20 to 1200 kDa) have been used as reducing agents and particle stabilizers. The obtained chitosan–Ag nanocomposites have been studied by UV–Vis and IR spectroscopy, X-ray powder diffraction analysis, and transmission electron microscopy. Nanocomposites have a “core-shell” structure, spherical shape with size up to 60.0 nm and the surface ξ-potential value >40.0 mV. Optimal parameters of synthesis (time, temperature, molecular weight of chitosan) of chitosan–Ag nanoparticles with highest antimicrobial activity against gram-positive and gram-negative bacteria and fungi have been found.