Preparation of composite films with controlled dispersion state of SiO2 nanoparticles by using polymer/SiO2 nanocomposite particles

Dispersion state of inorganic nanoparticles (NPs) in the composite films may significantly influence on the film properties. In the present study, polymer/SiO2 nanocomposite particles (NCPs) with various SiO2 grafting states (various grafting ratios, various linking patterns between SiO2 NPs, and various types of grafted chains), were prepared through in situ emulsion or in situ miniemulsion technique. These NCPs were used as building blocks to prepare composite films. The microscopic observations and surface composition analyses of the composite films manifest that the spatial distribution of SiO2 NPs in the composite films depends on the baking temperature, SiO2 grafting state, and the compatibility between SiO2 NPs and polymer matrix. The SiO2 NPs might display a cluster-like distribution, homogenous one, or locally aggregated one. The results from this study demonstrate how the grafting state of inorganic NPs is effective in controlling dispersion state of inorganic NPs and further determining the properties of composite films.