Preparation of Chitosan-Silver Nanoparticles in Nonaqueous Medium under Heating

Abstract

Chitosan-silver nanoparticles are prepared in nonaqueous medium. In this work, sodium dodecyl sulfate (SDS) was introduced into the dimethylformamide (DMF) solution during silver reduction from solution of its precursor salt AgNO3, acting as a stabilizing agent to prevent aggregation of silver nanoparticles, while chitosan is used as the solid support to embedded silver particles therein, resulting in chitosan-silver (CS-Ag) nanoparticle as suspension in the medium. The reaction started as homogeneous system which turned into heterogeneous with the formation of particles. The properties of CS-Ag nanoparticles are studied under two different salt concentrations and characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectroscopy (UV-Vis). Wide particle size distribution of synthesized nanoparticles depicts that concentration of AgNO3, which is responsible for the morphology, stability and particle size distribution, should be optimized, suggesting a lower salt concentration is favorable.