CONTACT-ANGLE HYSTERESIS IN CHLORINATED-HYDROCARBON WATER MIXTURES

Variations of two-phase capillary rise were conducted with water and a number of chlorinated hydrocarbons in glass capillaries cleaned with chromic-sulfuric acid. Contact angle hysteresis due to the advance or recession of a water-organic interface was investigated, relative to t he water phase. When water advanced, contact angles of 47.3-62.1-degre es were calculated. When water receded, equations based on the balance of interfacial and gravity forces within the capillary failed to yiel d single estimates of the interfacial angle. It was hypothesized that water-receding angles were approaching 0-degrees due to a film of wate r. This hysteresis was minimized in the smallest capillaries.