Fourier transform surface viscoelastic modulus of dilute aqueous solutions of surfactants. Improved computational methods

TLDR: In this article, the magnitude spectra of the modulus v were evaluated from the observed tansient surface tension decay, by proper data manipulation and by adaptation of FT algorithms, taking into account the particular characteristics of the time and frequency domain functions relevant to the examined dynamic properties of fluid interfaces.

Abstract: Computational procedures are devised which allow accurate magnitude spectra of the modulus ɛ(v) to be evaluated from the observed tansient surface tension decay. This is achieved by proper data manipulation and by adaptation of FT algorithms, taking into account the particular characteristics of the time — and frequency — domain functions relevant to the examined dynamic properties of fluid interfaces. Numerical examples, given for 1) exponential-type and 2) diffusion-controlled relaxation mechanisms, show satisfactory accuracy.