Small Molecule Sorption and Desorption in and Out of Iota‐Carrageenan Gels

Abstract

Small molecule sorption and desorption in and out of Iota‐Carrageenan was studied by using steady‐state fluorescence (SSF) technique. Pyranine dissolved in water used as fluorescence probe. Fluorescence emission intensity, I p from pyranine was monitored for studying sorption and desorption processes at various temperatures. The Fickian model was applied to produce sorption, Ds, early desorption, Ded, and desorption, Dd, coefficients. Corresponding activation energies were obtained and found to be 20.5 kJ mol−1, 7.0 kJ mol−1 and 34.9 kJ mol−1, respectively. The observed Ded value is an order of magnitude smaller than the Ds and Dd coefficients. On the other hand, sorption processes were shown to be twice as fast as desorption processes.