Gradient distribution of fluorine on the film surface of the organic–inorganic hybrid fluoropolymer

Inorganic–organic hybrid latex containing fluoride has been prepared in multistage emulsion polymerization in the presence of nano-SiO2 particles and alkoxysilane (γ-methacryloxypropyltri(isopropoxy)silane, MAPTIPS). The effects of fluoride and alkoxysilane on the morphologies of composite particles were observed and it was found that the encapsulation may be fulfilled in the presence of dodecafluoroheptyl methacrylate together with MAPTIPS whether using raw SiO2 particles or modified. The distribution of fluorine in different latex films was measured by X-ray photoelectron spectroscopy. It was indicated that the gradient distribution of fluorine from depth profile in the films may be enhanced by MAPTIPS and encapsulated SiO2 due to the bidirectional move of MAPTIPS and congregation of SiO2 on the film surface. Combining the results of XPS with AFM analysis, it was showed that the phase separation between organic and inorganic for encapsulated SiO2 was lightened, while it was so apparent for raw SiO2 that the orientation to the surface of fluorine was restrained in the lack of MAPTIPS.