THE TEMPERATURE-DEPENDENCE OF THE INTERFACIAL-TENSION OF AQUEOUS HUMAN ALBUMIN SOLUTION/DECANE

The adsorption kinetics of human albumin (HA) at a 0.02 mg ml(-1) aqueous solution/decane interface and the temperature dependence of the interfacial tension from 20 to 60 degrees C were studied using Axisymmetric Drop Shape Analysis. This is a non-perturbation method which allows us to study the interfacial tension for a long period of time, without a significant change in the interfacial area. Two criteria were applied to obtain ''experimental equilibrium'' values of the interfacial tension and interfacial pressure. The rate of change of interfacial pressure with temperature was found to be about 0.1 mJ m(-2) degrees C-1 from 20 to 45 degrees C. The interfacial pressures were found to be approximately 10 mJ m(-2) larger than those reported elsewhere for the HA solution/air interface at room temperature. For the concentration used, a plateau in the interfacial pressure was obtained and can be interpreted on the basis of saturation at temperatures above 45 degrees C.