Physicomathematical analysis of surface modification of polymers by glow discharge in SF6+N2 medium

In this paper, surface modification of dielectric polymers, having different physical and chemical properties (polyimide—PI, polystyrene—PS, Polyethylene terephthalate—PET), treated in contourized glow discharge in SF6+N2 gas medium near cathode was studied. The electret state, formed as a result of modification, caused an increase in the surface energy. Surface charge densities and contact angles of dielectric polymers whose surfaces were activated under identical conditions, were measured. Upon activation, formation of electret state on the dielectrics strained the sessile drop and consequently the contact angle changed. A mathematical model relating the contact angle and the surface charge density was derived. Experimental results agreed well with the theoretical model.