Effects of vacuum ultraviolet irradiation to lubricant layer on hard-disk media

We investigated the effects of 172-nm irradiation to examine the potential of ultraviolet treatment to bonded lubricant ratio and surface energy. The bonded ratio of lubricant reached almost 100%. The surface shows strong water-repellent properties. For example, the contact angle of water was a maximum of 110/spl deg/. Surface-free energy was estimated to be 12 mN/m, according to Zisman's plot. This value is lower than that of poly(tetrafluoroethylene).