Electrical transport behaviour of silver-PMMA nanocomposite films at low temperature

Abstract

In this study, the silver nanoparticles, capped with oleylamine, were embedded in polymethylmethacrylate (PMMA) using sonication to fabricate Ag–PMMA nanocomposites. The well-dispersed nanocomposite samples are analysed using UV-Vis absorption spectroscopy, atomic force microscopy and small angle X-ray scattering. The interfacial interaction of Ag nanoparticles and PMMA polymer is investigated using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. It is concluded that a ligand-exchange process occurs when capped silver nanoparticles are incorporated in PMMA polymer. Electrical resistivity of nanocomposite samples was measured by a four-probe technique in the 70–300 K range. The nanocomposites showed a transition with onsets at ∼230 and ∼160 K. They exhibited a semiconductor-like conductivity at higher temperatures, a rapid metallic conductivity at middle range and nearly temperature independent conductivity at lower temperatures.