A controlled morphology of polymeric nanocapsules via the density of surface vinyl group for the precipitation polymerization

The morphology of the resultant poly(ethyleneglycol dimethacrylate-co-methacrylic acid)/polydivinylbenzene (P(EGDMA-co-MAA)/PDVB) nanocapsules for in situ precipitation polymerization of divinylbenzene in presence of P(EGDMA-co-MAA) nanocapsules as templates was controlled by the density of the residual surface vinyl group of the P(EGDMA-co-MAA) nanocapsules, which was dependent on the cross-linking degree (EGDMA) for the distillation precipitation copolymerization of EGDMA and MAA. The morphology of P(EGDMA-co-MAA)/PDVB hybrid nanocapsules can be regulated from the separated domains, raspberry-like to a double-layer structure by adjusting the EGDMA cross-linking degree from 20% to 100% for P(EGDMA-co-MAA) nanocapsule templates with various densities of the surface vinyl group. As a result, the well defined raspberry-like P(EGDMA-co-MAA)/PDVB nanocapsules were obtained in presence of P(EGDMA-co-MAA) templates with the intermediate density of surface vinyl group during the precipitation polymerization. The morphology and structure of the P(EGDMA-co-MAA)/PDVB nanocapsules were characterized by Fourier transform infrared analyses (FT-IR), Zeta potential, transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and elemental analysis by ion chromatography.