Swelling of iota-carrageenan gels prepared with various CaCl2 content: A fluorescence study

Abstract

Iota carrageenan gels prepared with various CaCl 2 content were completely dried and then swelled in water vapor. Steady-state fluorescence (SSF) technique was used to monitor the swelling process of each iota carrageenan gels at various temperatures. Pyranine was used as a fluorescence probe. Apparent fluorescence intensity, I increased as swelling time increased for all gel samples. The increase in I was modelled using Li-Tanaka equation from which the swelling time constants, τ 1 and cooperative diffusion coefficients, D c were determined. It was observed that D c increased as the swelling temperature was increased. On the other hand at each temperature, it was seen that D c decreased as CaCl 2 content was increased. Activation energies for swelling were obtained and found to be 60.5, 61.0, 61.5 and 62.8 kJmol -1 for the gels prepared with increasing amount of CaCl content.

Carrageenans: Biological properties, chemical modifications and structural analysis – A review

“…Gels prepared from hydroxyalkyl j-carrageenan derivatives demonstrated decreased syneresis and could contribute to a wider industrial use of these polysaccharides. Recently, Tari and Pekcan (2008) demonstrated that the association of j-carrageenan with CaCl 2 can change the swelling properties of carrageenan gels, emphasizing the commercial relevance of carrageenans chemical modifications.…”

Superabsorbent polymers: A review on the characteristics and applications of synthetic, polysaccharide-based, semi-synthetic and ‘smart’ derivatives

“…Κ-carrageenan containing hydroxyalkyl groups has already been developed to create a gel with a decreased syneresis and therefore, a broader industrial scope [182]. The association of κ-carrageenan with CaCl2 changes the swelling capacity of the gel [183]. Another often used derivatization type characteristic for these polysaccharides is alkalization.…”