Application of Photothermal Techniques in the Determination of the Water–Vapor Diffusion Coefficient and Thermal Effusivity of Hydrogels

Abstract

The main objective of this work is to determine the effect of different sodium alginate concentrations in hydrogels on their water–vapor diffusion coefficient (WVDC) and thermal effusivity (\(e_\mathrm{s})\). These physical parameters were measured by photoacoustic and pyroelectric techniques, respectively. The results indicate that the higher values for the WVDC are presented at a concentration of 2 % sodium alginate. At lower concentrations of sodium alginate, the sample thermal effusivity increases, with a value close to the water thermal effusivity.