Non-equilibrium surface thermodynamics. Measurement of transient dynamic surface tension for fluid—fluid interfaces by the trapezoidal pulse technique

The trapezoidal pulse perturbation is shown to be an attractive procedure for the measurement of dynamic properties of fluid—fluid interfaces. The surface response characterizes the surface relaxation behavior well. Theoretically, this procedure has foundations within the framework of linear non-equilibrium thermodynamics. From the experimental point of view, the procedure offers the possibility of checking the experimental reliability and exhibits practical aspects due to the short duration of the surface response. Benefits are also evident in data processing.