A new observation in surface chemistry: the variation of liquid–solid–gas contact angle with change in gas pressure

The contact angles of water and of diiodomethane (DIM) on Teflon LFEP and on polymethylmethacrylate (PMMA), and also on a copolymer of hydroxybutyrate and hydroxyvalerate, has been measured. It was found that the contact angle decreases with pressure, in all but one of the systems studied. The decrease in contact angle is appreciable (of the order of 0.2° per atmosphere), except for the case of water on PMMA.