Immobilization of L-Cysteine onto Poly(ethylene glycol) Polymerized by Surface-Wave Plasma

Abstract

Poly(ethylene glycol) (PEG) terminated with hydroxyl functional groups is expected to play the roles of a hydrophilic layer to alleviate the aging effect and an intermediate for the subsequent covalent immobilization of L-cysteine. A plasma-induced grafting-polymerization or crosslinking technique using microwave-excited surface-wave plasma for grafting PEG molecules on a polyurethane (PU) surface is presented. The effects of Ar plasma pretreatment and post-treatment on the in situ polymerization or crosslinking of PEG molecules are investigated. The effect of Ar plasma pretreatment on the surface shows that pretreatment can induce the adsorption of more PEG molecules on the surface for the subsequent post-treatment. Increasing the post-treatment power and post-treatment time can achieve the in situ polymerization or crosslinking of PEG molecules, whereas excessively increasing the post-treatment power and post-treatment time can induce excessive damage to the hydroxyl functional groups.