iCVD growth of poly(N-vinylimidazole) and poly(N-vinylimidazole-co-N-vinylpyrrolidone)

The imidazole group plays an important role in α-chymotrypsin catalysis, metal-ion complexation, counterion or dye binding. Poly(N-vinylimidazole), PVI, is also a good model polymer interacting with neutral salts. The poly(N-vinylimidazole-co-N-vinylpyrrolidone) copolymer P(VI-co-VP), can be used to produce highly functionalized polymers. PVI and P(VI-co-VP) thins films were achieved via initiated chemical vapor deposition (iCVD), a solvent-free process to form films under mild conditions. The polymerization was initiated by hot wire heated tert-butyl peroxide (TBPO). The chemical structure and compositions of the polymers were analyzed using FTIR and XPS. The growth rate of PVI as a function of the pressure inside the iCVD reactor was measured to be 1 nm/h mTorr. The XPS results show that the functional groups were retained in the polymer deposited. For the P(VI-co-VP) deposition, there are more VI groups found in the co-polymer chain even when the reacting monomers were fed in the same ratio.