Effect of diamond-like carbon thin film deposition on the resistance of polycarbonate to radiation-induced degradation

摘要

The effects of high-energy gamma irradiation on the characteristics of polycarbonate specimens (Lexan plate) deposited with a thin film of diamond-like carbon (DLC) were investigated. A plasma enhanced CVD method was adopted in depositing a thin DLC film on the polycarbonate specimens. Both specimens, with DLC film and without it, were exposed to the gamma radiation emitted from a Co-60 source to the level of 10~6 rad for comparing their properties. The concentration of free radicals in the undeposited specimen rapidly decreased to 4.4 of the initial value, while that in the specimen deposited with DLC film remained at 60. It is suggested that DLC inhibits the oxidation reaction between free radicals and oxygen in the surrounding air. This study shows experimental evidence that the resistance to radiation-induced oxidation of a polymer can be enhanced by depositing a thin layer of DLC.