Syntheses and surface analysis of novel poly(dimethylsiloxane) containing amphiphilic graft copolymers.

摘要

A series of novel amphiphilic graft copolymers consisting of a hydrophilic poly(2-hydroxyethyl methacrylate) [poly(HEMA)] or poly(2,3-dihydroxypropyl methacrylate) [poly(DHPMA)] backbone and hydrophobic poly(dimethylsiloxane) (PDMS) side chains have been synthesized. The graft copolymers were prepared via both photoinduced-radical and anionic polymerization techniques. Using angle-dependent X-ray photoelectron spectroscopy (XPS), the effects of the PDMS graft length, the PDMS bulk content and the MWD as well as the hydrophilicity of the backbone on the surface composition of these graft copolymer films were investigated under both dry and wet conditions. It was found that for a given PDMS bulk content, a longer PDMS graft gives a surface richer in siloxane. However, the MWD has little effect on the air (free) surface composition. With increasing PDMS bulk content, the PDMS surface concentration increases for poly(HEMA-g-DMS) graft copolymers, but no significant difference was observed for poly(DHPMA-g-DMS)s. As expected, upon exposure to water, the amphiphilic graft copolymers underwent a dramatic surface structure reorganization.; An additional study is reported on evaluation of the potential of hybrid films to support adhesion and proliferation of primary respiratiory epithelial cell. A series of collagen/PVA hybrid films with different weight percent ratio were prepared. The surface composition of these films were investigated by using angular-dependent XPS. The results showed that the PVA component dominated the free surface even for the film with higher ratio of collagen component. It was found that with increasing sampling depth, the concentration of collage within the surface region slightly increases. The cell culture experiment results showed that the hybrid films supported more robust cell growth than either pure materials.