Spectroscopic analysis of durable 2,3-epoxy-1-propanol plasma polymerized films

Plasma polymerization of 2,3-epoxy-1-propanol was carried out in a customized apparatus whereby rotation of the sample stage at a constant speed of 5 rpm/s ensured homogeneous deposition of polymer particles. FTIR and XPS spectroscopy were used to determine the structure of 2,3-epoxy-1-propanol plasma polymerized films. We observed CO, OH and CO functional groups, which originate from free radical interactions, remained in the epoxy polymer film after deposition. Corresponding XPS data also confirmed that the original epoxy group is retained in the deposited polymer film. The apparent iso-electric point of 200 nm epoxy plasma polymerized film was pH 3.5 in 100 mM citrate buffer at 25 °C. The chemical stability of the epoxy plasma polymerized film was assessed by tolerance to a wide range of acid and alkali buffer solutions.