Preparation and characterization of UV-curable ZnO/polymer nanocomposite films

A series of novel nano-ZnO/polymer composite films with different ZnO contents was prepared through incorporation of pre-made colloidal ZnO particles into monomer mixtures of urethane-methacrylate oligomer and 2-hydroxyethyl methacrylate, followed by ultraviolet (UV) radiation-initiated polymerization. The colloidal ZnO nanoparticles with a diameter of 3-5 nm were synthesized from zinc acetate and lithium hydroxide in ethanol via a wet chemical method. In order to stabilize and immobilize the ZnO particles into the polymer matrix, the ZnO nanoparticles were further capped using 3-(trimethoxysilyl)propyl methacrylate. Thermogravimetric analyses show that the ZnO nanoparticles were successfully incorporated into the polymer matrix and these ZnO/polymer composites have a good thermal stability. Transmission electron microscopy studies indicate the ZnO nanoparticles were uniformly dispersed in the polymer and they remained at the original size (3-5 nm) before immobilization. All nanocomposite films with ZnO particle contents from 1 to 15 wt% show good transparency in the visible region and luminescent properties. In addition, composite films with high ZnO content (> 7 wt%) are able to absorb UV irradiation below 350 nm, indicating that these composite films exhibit good UV screening effects. (c) 2006 Society of Chemical Industry