Morphology and kinetic mechanism of facile one-step preparing TiO₂/polyacrylate/TiO₂multilayer core–shell hybrid emulsion via miniemulsion polymerization

In this paper, we report a facile method for the preparation of TiO2/polyacrylate/TiO2 multilayer core–shell hybrid emulsion through polymerization. The chemical compositions of the copolymer were studied with Fourier transform infrared. TEM images reveal that nanocomposites show different core–shell structures with different TiO2 contents. As the weight percentage of TiO2 is 2 wt% (based on monomer, same below), there are no TiO2 cores in some nanocomposites. When TiO2 increases to 3 wt%, the TiO2/polymer/TiO2 multilayer core–shell composite particles are prepared. But the TiO2 shells disappeared when the TiO2 content kept increasing. TGA shows that the TiO2 dispersed in latex films uniformly and the thermal stabilization improved with increasing TiO2 contents. The effect of operating variables such as polymerization temperature and the concentrations of polymerizable emulsifier, initiator, extremely hydrophilic monomer, modified TiO2 and HD on the kinetic behaviors was investigated. The formation mechanism of TiO2/polymer/TiO2 multilayer core–shell structure was inferred.