We describe a new method for measuring the interfacial dilatational viscosity of interfaces exhibiting Boussinesq, i.e., Newtonian surface behavior. The surface shear dilatational viscosity of the gelatin-surfactant solution was measured. This is the first time that experimental studies on the effect of surface-active agent concentration and surface temperature on surface dilatational viscosity are reported. Over the entire range of surfactant concentration, the surface dilatational viscosity increases with increasing temperature. This surface dilatational viscosity-temperature relationship should be compared with that of surface shear viscosity, which decreases with increasing temperature up to 40 °C and subsequently increases with temperature. Apparently, the transition from the β-conformation to α-conformation of polypeptides that is proposed to take place at 40 °C has no effect on the temperature dependence of the surface dilatational viscosity.
Relation:
Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering Volume 63, 1990, Pages 544-548
