Enhancement of thermal stability and phase relaxation behavior of chitosan dissolved in aqueous l-lactic acid: Using ‘silver nanoparticles’ as nano filler

Abstract

Chitosan films with various compositions of silver nanoparticles were prepared by solution casting with an aqueous solution of chitosan and l-lactic acid. The chitosan/Ag nanocomposites were characterized by wide angle X- ray diffraction (WAXD) and UV-vis spectroscopy. An analysis of the surface topography and size of the Ag nanopar- ticles (≤100 nm) were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Thermogravimetric analysis (TGA/DTA) confirmed the increase in thermal stability with increasing Ag nanoparticle content in the nanocomposites. Dynamic thermal analysis (DMA) was used to examine the phase relax- ation behavior of chitosan and its nanocomposites. The conductivity of chitosan/Ag nanocomposites was considered with respect to the frequency. Contact angle measurements were used to characterize the surface twistability, surface cleanliness, and hydrophilic/hydrophobic nature of the surface.