Effect of Swelling of a Polymer Surface on Advancing and Receding Contact Angles (original) (raw)

alkanes between the monolayer molecules; this is not possi-The kinetics of modification of a fluoropolymer coating (FC ble for the longer alkanes whose dimensions exceed the cross 722, 3M Company) during its contact with octane, dodecane, and section of the monolayer cavities (3). The penetration of hexadecane is studied via measurement of quasi-static (velocity the liquid into the polymer surface might loosen the polymer independent) advancing and receding dynamic contact angles. A chains and cause surface swelling. As noted by Adam (4) decrease in both angles with the time of contact between solid and this process also results in a decrease of the static contact liquid is observed and it is interpreted as the result of swelling of angle. Such a decrease of the advancing contact angles of the polymer. By means of a theoretical extrapolation of the u R (t) CH 2 I 2 , a-bromonaphthalene, and aniline on crosslinked data to t Å 0, based on an equation relating u R (t) to swelling polystyrene was observed by Good and Kotsidas (5). kinetics, the experimentally inaccessible receding contact angle on dry coating, u 0 R , is determined. The contact angle hysteresis on