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The surface of commercial TiO2 nanoparticles was modified by titanate coupling agent, JSC(isopropyl tricarboxytate titanate), FTIR spectrum confirmed that organic functional groups were successfully grafted onto the surface of TiO2 nanoparticles. The SEM micrographs indicated that the aggregation of modified TiO2 was reduced and most of the particles were approximately 20 nm.

The well-dispersed core-shell nanospheres (TiO2-g-PS) were synthesized via nano-TiO2 grafting polymerization and were used to prepare PS/TiO2 nanocomposites by melt blending. The tensile and thermal properties of the nanocomposites were measured by means of tensile test and thermogravimetric analysis (TGA). The fracture surface of the tensile test specimens was also explored through scanning electron microscopy (SEM). The reasults show that the tensile performance and thermal stability of the PS/TiO2 nanocomposites depend on the loading and state of the TiO2 in the PS matrix. The optimal properties of nanocomposites are achieved at 1.0wt% of TiO2-g-PS nanoparticles and the tensile strength is increased up to 43.6% comparing to the pure PS. The onset temperature at which 10% mass is lost is increased 10oC. The dispersion of the particles and interfacial adhesion lead to enhance these properties.

TiO2-g-Polystyrene(PS) nano-microspheres were prepared by grafted styrene monomer on the surface of nano-TiO2 particles via emulsion polymerization, and its surface and morphology were studied by Transmission electron microscopes(TEM), Fourier transform infrared spectroscopy(FTIR) and thermal gravimetric analysis(TGA). The results showed that the TiO2-g-PS nano-microsphere had a structure of sphericity composed of TiO2 and PS as core and shell respectively. The core-shell nanoparticles were subsequently used as filler in a PS matrix, and the impact strength of the TiO2-g-PS/PS composites were studied. The results showed that the impact strength of the composite material could be improved obviously, the maximum value of impacted strength of the TiO2-g-PS/PS was 1.75kJ/m2, which was 180% higher than that of pure PS. Drawing from the results, it could be confirmed that these core-shell TiO2-g-PS nanosphere fillers could toughen the PS matrix.

Nano-TiO2 was modified with a titanate coupling agent, LICA38 [neopentyl (dially) oxy, tri (-dioctyl) pyrophosphate titanate]. X-ray photoelectron spectroscopy (XPS) was used to evaluate the surface characteristics of the bare and the modified nano-TiO2. It was demonstrated that the carbon content of the bare TiO2 is 37.9 atm. %, and that of the modified TiO2 is 47.2 atm. %. Moreover, the density of the -C-H (-C-C) and -C-O groups increases due to modification, and the atomic percentage of C=O and -OH groups reduces. These results indicate that the -C-H (-C-C) and -C-O groups from LICA38 have been introduced to the surface of nano-TiO2 by coupling reaction with the hydroxyl groups.