A new method to estimate the sol-gel transition entropy in physically gelling systems

作者：Sakai Takashi; Horinaka Jun ichi; Takigawa Toshikazu^*

来源：Polymer Journal, 2015, 47(3): 244-248.

DOI：10.1038/pj.2014.98

A Clapeyron-type equation is presented to estimate the transition entropy for the sol-gel transition of physical gels, based on simple thermodynamics for the gels under load. The transition entropy and the transition enthalpy were estimated for kappa-carrageenan/water and gellan/water systems using this Clapeyron-type equation. For the carrageen systems, the transition entropy per unit gel volume (Delta S-V) remained constant, regardless of the polymer concentration and the species and concentration of the added salts. A similar behavior was also observed for the gellan systems. These results suggest that the structure of the crosslink domains of the gels is almost identical, regardless of the polymer concentration and the species and concentration of the added salts, if the comparison was made with a fixed polysaccharide. The values of Delta S-V obtained in this study were higher than those obtained using calorimetry as reported in the literature; however, the difference was not large.

• 出版日期2015-3