Ultrasonically assisted in situ emulsion polymerization: a facile approach to prepare conducting copolymer/silica nanocomposites

摘要

Ultrasonically assisted in situ emulsion polymerization was used to prepare electrically conducting copolymer poly(aniline-co-p-phenylenediamine) [poly(Ani-co-pPD)] and silica (SiO_2) nancomposites. This approach can solve problems in the dispersion and stabilization of SiO_2 nanoparticles in the copolymer matrix. It was found that the aggregation of SiO_2 nanoparticles could be reduced under ultrasonic irradiation. Scanning transmission electron microscopy (STEM) confirmed that the resulting poly(Ani-co-pPD)/SiO_2 nanocomposite particles were spherical in shape, in which SiO_2 nanoparticles were well dispersed. The comonomer molecules were absorbed on the surface of SiO_2 particles and then polymerized to form core-shell nanocomposite. The incorporation of SiO_2 in the nanocomposite was supported by Fourier transform infrared spectroscopy (FT-IR). UV-visible spectra of the diluted colloid dispersion of nanocomposite particles were similar to those of the neat copolymer. Conductivity of nanocomposites was higher than the value obtained for the neat copolymer.