Improving surface hydrophobicity of glass using an atmospheric pressure plasma jet array in Ar/TMS

The atmospheric pressure plasma jet (APPJ) in Ar/TMS (Trimethysilanol) is used to improve the surface hydrophobicity of glass, and a jet array composed of three linear connected jets is generated to increase the treatment scale and area. The discharge characteristics of the jet array are studied to determinate the treatment parameters, and the surface properties of the glass are studied through water contact angle (WCA), AFM, SEM, FTIR and XPS. The effects of TMS content and treatment time on WCA are investigated, and the optimum treatment conditions for hydrophobicity modification are obtained. Results show that jet array plasma with good uniformity can be obtained at certain applied voltage. The WCA increases from 60° to its maximum value of 110° after treatments at treatment time of 240 s and TMS content of 0.04%. The plasma treatment can induce the incorporation of hydrophobic bonds such as Si-C, Si-O onto the surface and the changing of surface topography, and the replacement of hydrophilic bonds on the glass surface by active Si containing species produced in the plasma is the main reason accounting for the improvement of surface hydrophobicity. The variation of the intensities of Si species is found to agree well with those of the measured WCA values on the surface.