Fabrication and thermal properties of self-assembled silver multilayer films on poly(ethylene terephthalate) substrate

This article uses the layer-by-layer self-assembly method to fabricate multilayer film on poly(ethylene terephthalate) substrate. The hydrolization of poly(ethylene terephthalate) film was primarily performed with sodium hydroxide aqueous solution to produce a carboxyl-enriched surface. The multilayer films were fabricated by the alternate adsorption of the oppositely charged poly(diallyldimethylammonium chloride) and silver nanoparticles on poly(ethylene terephthalate) substrate. The assembly process was monitored by UV–VIS spectroscopy and inductively coupled plasma. The surface topography and chemical composition of the self-assembly films was characterized by atomic force microscopy and X-ray photoelectron spectroscopy. The images indicated that the silver nanoparticles were successfully assembled and well distributed on the substrate. Furthermore, X-ray photoelectron spectroscopy confirmed the presence of metallic silver on the poly(ethylene terephthalate) substrate. The thermal properties of the multilayer films were investigated by thermogravimetric analysis and dynamic mechanical analyser. The results revealed that the storage modulus of ten-bilayer films decreases with temperature increasing and the glass transition temperature of ten-bilayer films have been found to be 99.3°C, whereas it is 94.8°C for the original poly(ethylene terephthalate) film.