Hydrophilic behavior of methyl-terminated organosilica thin films modified by atmospheric-pressure water vapor plasma

摘要

? 2022The surface properties of methyl-terminated organosilica films modified by atmospheric-pressure water vapor plasma were investigated. The use of plasma modification resulted in an immediate decrease in the water contact angle of the organosilica films from 100° to <5° because of the oxidation of methyl groups to form oxygen-containing groups such as Si-OH. The plasma-modified films underwent a moderate hydrophobic recovery. The water contact angle increased to 50° after being stored in a dry atmosphere. Hydrophobic recovery can be suppressed by storing the films in a humid atmosphere or water. Contact angle measurements using multiple probe fluids revealed that the changes in surface hydrophilicity during long-term storage were ascribed to the rotation of Si-OH toward the bulk phase.