Preparation and characterization of polyelectrolyte/silver multilayer films on PET substrates and its antibacterial property

Silver nanoparticles (AgNPs) were synthesized by a chemical reduction method that reduced silver nitrate with sodium borohydride. Hydrolysis of poly(ethylene terephthalate) (PET) in concentrated alkaline solution produced a carboxyl‐enriched surface. The ultrathin multilayer films were fabricated by sequential adsorption of the positively charged poly(diallyldimethylammonium chloride) (PDDA) and negatively charged AgNPs colloid solution on PET substrates by an layer‐by‐layer (LBL) self‐assembly technique. The multilayer film growth process on PET substrates was monitored by UV–vis absorption spectroscopy. The surface morphology and chemical composition of the multilayer film was characterized by field emission scanning electron microscope (FESEM), scanning probe microscope (SPM), and X‐ray photoelectron spectroscopy (XPS). The results showed that the AgNPs were uniformly dispersed on the PET film as metallic silver state. The surface wettability of multilayer film was investigated using sessile drop method. The results suggest that the PET films after assembled 10‐bilayer PDDA/AgNPs multilayer films exhibits good antibacterial property. POLYM. COMPOS., 36:1161–1168, 2015. © 2015 Society of Plastics Engineers