Mechanical properties under nanoindents in gold nanoparticles reinforced poly(vinyl alcohol) nanocomposite films

Keywords:
gold nanoparticles, nanocomposite, mechanical properties, nanoindentaion

Abstract:
Free standing films of gold nanoparticles reinforced poly(vinyl alcohol) (PVA) nanocomposite are synthesized by a novel chemical method with selective Au-contents varied from 0.1 to 5.0 wt%. The color change in the Au-PVA nanocomposite films from violet to yellowish color is a characteristic of forming Au-nanocrystals (NCs) of varying sizes and/or morphologies embedded in the PVA molecules. In order to study the mechanical reliability of these films, the mechanical properties such as elastic modulus (E-modulus), hardness (H) and yield stress are studied using nanoindentaion technique. Both E-modulus and H show a decreasing trend followed by an increased value with the increase in the Au-content in the samples. The H-value of the films decreases first from 0.29 GPa in virgin PVA to 0.23 GPa in 0.5 wt% to value of 0.31 GPa in 2 wt% Au-PVA film. Also the E-modulus decreases from 8.19 GPa in PVA film to 6.48 GPa in 0.5 wt% Au-PVA film followed by an increase in the value upto 7.3 GPa in 2 wt% Au-PVA film. In this present paper, these results are analyzed in correlation with the microstructure and are found useful for device applications.

Nanotech 2008 Conference Program Abstract