Synthesis of Water-Based Dispersions of Polymer/TiO(2) Hybrid Nanospheres

We develop a strategy for preparing water-based dispersions of polymer/TiO(2) nanospheres that can be used to form composite materials applicable in various fields. The formed hybrid nanospheres are monodisperse and possess a hierarchical structure. It starts with the primary TiO(2) nanoparticles of about 5 nm, which first assemble to nanoclusters of about 30 nm and then are integrated into monomer droplets. After emulsion polymerization, one obtains the water-based dispersions of polymer/TiO(2) nanospheres. To achieve universal size, it is necessary to have treatments with intense turbulent shear generated in a microchannel device at different stages. In addition, a procedure combining synergistic actions of steric and anionic surfactants has been designed to warrant the colloidal stability of the process. Since the formed polymer/TiO(2) nanospheres are stable aqueous dispersions, they can be easily mixed with TiO(2)-free polymeric nanoparticle dispersions to form new dispersions, where TiO(2)-containing nanospheres are homogeneously distributed in the dispersions at the nanoscale, thus leading to various applications. As an example, the proposed strategy has been applied to generate polystyrene/TiO(2) nanospheres of about 100 nm in diameter.