Sterilization of Polymeric Material by Plasma-Based Ion Implantation

摘要

Ion bombardment with several-keV energy is applied to sterilization of a polymer film as a fundamental study for treating polymer bottles in a future. The sterilization occurs due to physical reaction of high energy ions with bacteria spores put on the polymer film, although most of traditional "plasma sterilizations" do due to plasma-enhanced chemical reaction with them. The plasma-based ion implantation (PBII) is utilized since it can be applicable even to insulated materials without electric charging problems. Microwave plasma in magnetic field is generated with nitrogen gas. Bacillus subtilis spores on a polymer film are bombarded by ions with the energy of up to 10 keV. Since the ion bombardment is carried out with pulse mode of 0.5 % in duty cycle, the film temperature is kept so low as not to damage the polymer with heat. The dependencies of ion energy and ion fluence on the sterilization rates are obtained.