Wetting Control of Polymer Solution on Roughened Solid Surfaces by Wet-blast Technique

Abstract

Spreading of organic solution can be improved drastically on a solid surface after the wet-blast treatment. The wet-blast treatment has an ability of morphology control of various kinds of surfaces. Various organic liquid can spread spontaneously on a substrate due to spreading energy S. By analyzing surface energies of the treated surfaces, the wet-blast treatment has a similar effect of the increase of dispersion component γd, that is, hydrophobic surface. Spontaneous spreading of the polymer solutions can be explained to be negative value of the spreading coefficient. High wetting surface can be realized by an oxygen plasma treatment. However, the substrate surfaces become considerable hydrophilic property due to increase of the polar component γp, that is, hydrophilic surface. It can be considered that water vapor adsorbed the hydrophilic substrate and induce corrosion of metal components such as an electrode and micro wire lines. The roughened surface can act to prevent liquid condensation after spreading on the substrate, so-called pinning effect. The spontaneous spreading on the substrate after wet-blast treatment can be explained on the multiplier effect of nominal dispersion increase and pinning.