SURFACE DYNAMICS OF PLASMA POLYMERS STUDIED BY THE WILHELMY FORCE MEASUREMENT

Surface dynamic change during the Wilhelmy force measurement was inves tigated for microscope cover glasses coated by trimethylsilane (TMS) a nd TMS + oxygen plasma polymers. The intrinsic hysteresis which is cau sed bg the surface configuration change on water immersion can be dete cted by the deviation of shape of the force loop. The deviation of the second immersion line from the first immersion line and also of the i nitial slope of the second immersion (in the transient stage where the change of meniscus takes place) can be taken as a measure of the exis tence and the extent of the surface dynamic changes due to water immer sion. These parameters are dependent on the speed of immersion or emer sion employed in the force measurement and can be enhanced by halting the motion at the end of immersion or emersion.