Ag nanoparticles induced modification in microhardness of polyvinyl alcohol

Silver (Ag) nanoparticles play a significant role in nanomaterials science and technology due to many peculiarities. One of the main characteristic of Ag nanoparticles is the occurrence of surface plasmon resonance (SPR) due to the collective oscillation of free electrons in visible region. Due to this distinctive feature Ag nanoparticles have numerous applications such as in catalysis, surface enhanced Raman spectroscopy, photonics, solar cells etc. In the present work, no additional stabilizing agent has been used. The characteristic SPR peak appears at around 405 nm in UV-Visible absorption spectra of PVA-Ag nanocomposite films, thereby confirming the nanocomposite formation. The synthesized nanocomposite films were structurally characterized using fourier transform infrared (FTIR) and Raman spectroscopy. FTIR spectra of PVA-Ag nanocomposite film indicates that PVA matrix is modified by Ag nanoparticles which is in agreement with the results obtained using Raman spectroscopy. TEM as well as FE-SEM micrographs reveal that Ag nanoparticles are mostly spherical in shape. The knoop microhardness number of the nanocomposites was found to increase from 2.4 Kgf/mm for PVA to 12.1 kgf/mm for PVA-Ag nanocomposite film loaded with 0.062 wt% Ag nanoparticles. Copyright © 2018 VBRI Press.