Fabrication and Characterization of Silver−Polyvinyl Alcohol Nanocomposites

TLDR

The study examined how silver nanoparticles affect the properties of poly(vinyl alcohol) (PVA). The nanocomposite was prepared by mixing a colloidal solution of silver nanoparticles with a water solution of PVA in appropriate ratios, then evaporating the solvent to form films with varying inorganic content. Atomic absorption spectroscopy revealed Ag loadings of 0.19, 0.33, and 0.73 wt %; TEM showed ~20 nm particles; the composites exhibited ~40 °C higher thermal stability, a glass‑transition shift up to 20 °C, increased Young’s modulus and strength with higher Ag content, but reduced stress‑relaxation stability compared to pure PVA.

Abstract

The influence of silver (Ag) nanoparticles on the properties of poly(vinyl alcohol) (PVA) was investigated. The nanocomposite was prepared by mixing a colloidal solution consisting of silver nanoparticles with a water solution of PVA in appropriate ratios. Composite films with different contents of inorganic phase were obtained after solvent evaporation. The contents of the inorganic phase in the nanocomposites were determined by using atomic absorption spectroscopy (AA) for silver, and were found to be 0.19, 0.33, and 0.73 wt %. Transmission electron microscopy (TEM) of the nanocomposite films revealed the presence of Ag particles with average diameter of 20 nm. Comparison of the thermal properties of the pure polymer and the nanocomposite films showed that the thermal stability is improved by about 40 °C, and the glass transition temperature is shifted to a higher temperature up to 20 °C for the highest content of the nanofiller. An increase in Young's modulus and strength of the nanocomposite was also observed with an increase in Ag content, indicating significant reinforcement of the matrix in the presence of nanoparticles. Stress relaxation measurements revealed reduced stability of the nanocomposite upon prolonged loading, compared to the pure PVA matrix.