Hydrophobic treatment of organics against glass employing nonequilibrium atmospheric pressure pulsed plasmas with a mixture of CF4 and N2 gases

A hydrophobic organics surface selectively against glass was realized by employing nonequilibrium atmospheric-pressure pulsed plasmas with a mixture of CF4 and N2 gases. The organic surface was drastically altered to have a high hydrophobicity, while the glass surface itself remained hydrophilic after the plasma treatment with the addition of a small amount of CF4 to the N2 gas. After 100 CF4/N2 plasma treatments, no thin film deposition was observed on the organic material. To investigate the characteristics of the CF4/N2 plasma, the exhaust gas from the plasma was measured by using ion attachment mass spectroscopy (IAMS). The IAMS spectrum indicated that the amounts of CF3 and F radicals were increased drastically with increasing addition of CF4. A mechanism of the selective surface modification was clarified on a result of surface chemical bonding with the gas phase.