Diffusion coefficient measurements of transparent liquid solutions using Moiré deflectometry

Abstract

In this study the Moiré deflectometry technique is applied to the investigation of diffusion dynamics in transparent liquid mixtures. We describe the experimental details and present theoretical analysis for obtaining the magnitude of diffusion coefficient using the Moiré fringe patterns. The theoretical aspects of the method are presented and the relationship between the Moiré fringes shift and the diffusion coefficient is derived. Our method is applied for measuring the diffusion coefficient of sugar in pure water at room temperature. The value of D = 0.66 (±0.05) × 10−5 cm2 s−1 is obtained for diffusion of sugar molecules in pure water and it is in excellent agreement with the reported value in literatures.