Fabrication of zinc oxide/poly(styrene) grafted nanocomposite latex and its dispersion

Zinc oxide nanoparticles, with an average size of about 40 nm, were encapsulated by polystyrene using in situ emulsion polymerization in the presence of 3-methacryloxypropyltrimethoxysilane (MPTMS) as a coupling agent and polyoxyethylene nonylphenyl ether (OP-10) as a surfactant. Polymerization mechanism of nanocomposite latex was discussed. Transmission electron microscopy (TEM) proved the presence of ZnO nanoparticle appeared to be monodisperse in nanosize in polymer composite particles. ZnO/PS nanocomposites were characterized by Fourier transform infrared spectra (FT-IR), X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results of FT-IR and XPS revealed that the surface of ZnO particle was successfully grafted by PS through the link of the coupling agent between ZnO and polymer. TGA and DSC results indicated an enhancement of thermal stability of composite materials compared with the pure polymer. SEM (scanning electron microscope) images showed a perfect dispersion of the ZnO particles in latex film. In addition, UV-visible absorption measurements demonstrated that the ZnO/PS composite coatings display a perfect performance of absorbing UV light.