Poly(dimethylsiloxane)-containing thermoplastic elastomer/gold-silver alloy nanocomposites for thermally/oxidatively stable and antimicrobial coating

Abstract

Polymer materials with embedded silver (Ag) nanoparticle (NP) are of considerable interest owing to their enhanced antimicrobial activity and physical properties compared to host polymer. Antimicrobial and thermally/oxidatively stable coating not only enhances the durability of the coated material but also reduces the growth of bacteria/fungus and thus reduces the chance of infection. For this purpose, we have prepared polydimethylsiloxane-containing predominantly poly(meth)acrylates-based pentablock thermoplastic elastomer (TPE)/gold (Au)–Ag alloy nanocomposites (NCs) with antimicrobial activity and enhanced physical properties. In situ simultaneous reduction of appropriate amount of metal salts in the presence of block copolymer produced Au–Ag NPs of size 5–10 nm. Such embedded 5–10 nm sized particles (loading, 0.1–0.2 wt%) improved the mechanical property, thermal/oxidative stability, and antimicrobial activity of the NCs. The NC films also exhibited tunable surface wetting behavior and optical properties. The NC films showed low level of Ag leaching as confirmed by inductively coupled plasma spectrometer and UV–visible spectroscopy. Improved thermal/oxidative resistance of the TPE/Au–Ag alloy NCs enhanced antimicrobial activity, together with low level of leaching characteristic of the embedded NPs deemed suitable for further use of these NCs material for antimicrobial and oxidatively stable coating applications. POLYM. COMPOS., 36:2103–2112, 2015. © 2014 Society of Plastics Engineer