Facility for Adsorption and Surface Tension Studies (FAST) on Board of Shuttle STS-107 Mission: Determination of the surface dilational modulus as a function of concentration and temperature for aqueous solutions of dodecyl-dimethyl-phosphine-oxide

Measurements of dynamic-surface-tension responses to harmonic surface perturbations, in the low-frequency range, are reported for aqueous solutions of n-dodecyl-dimethyl-phosphine-oxide. From the primary observed results of the steadystate surface oscillation behaviour, the inherent surface dilational modulus is determined at different frequencies, at various concentrations up to the critical micellar concentration and at three temperatures (i.e., at T = 15, 25 and 35 °C). The obtained experimental values are successfully interpreted in terms of the diffusion-controlled model. The experiments grant reliable information about the constitutive dynamic properties of air-liquid single interfaces.