Synthesis, mechanical and I –V characteristics of Ag–PVA nanocomposite films

Hybrid polymer–inorganic nanocomposites have been prepared from an aqueous solution of polyvinyl alcohol (PVA) and silver nitrate (AgNO3). The silver nanoparticles have been generated in PVA matrix by reduction of silver ion with PVA molecules at 60–70 °C over a magnetic stirrer. X‐ray diffraction studies, UV–visible analysis, transmission electron microscopy, scanning electron microscopy and current–voltage analysis were used to characterize the nanocomposite films prepared. The X‐ray diffraction studies showed that silver metal is present in a face‐centered cubic (fcc) crystal structure with average crystallite size 19 nm, which grows to 22 nm on annealing the film at 150 °C in air. This is in good agreement with the result obtained from TEM. The UV–visible spectrum shows a single peak at 433 nm, arising from the surface plasmon absorption of silver colloids. This result clearly indicates that silver nanoparticles are embedded in PVA. An improvement of mechanical properties (storage modulus) was also noticed due to a modification of PVA up to 0.5 wt% of silver content. The current–voltage (I–V) characteristics nanocomposite films obey Ohm's law and the current drawn increases with increasing Ag content in the films. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)