NMR study on the network structure of a mixed gel of kappa and iota carrageenans

作者：Hu, Bingjie; Du, Lei; Matsukawa, Shingo^*

来源：Carbohydrate Polymers, 2016, 150: 57-64.

DOI：10.1016/j.carbpol.2016.04.112

• Mixture of carrageenans
• Gradient NMR
• Diffusion coefficient
• Gelation
• Microscopic structure

The temperature dependencies of the H-1 T-2 and diffusion coefficient (D) of a mixed solution of kappa-carrageenan and iota-carrageenan were measured by NMR. Rheological and NMR measurements suggested an exponential formation of rigid aggregates of kappa-carrageenan and a gradual formation of fine aggregates of iota-carrageenan during two step increases of G'. The results also suggested that longer carrageenan chains are preferentially involved in aggregation, thus resulting in a decrease in the average Mw of solute carrageenans. The results of diffusion measurements for poly(ethylene oxide) (PE O) suggested that kappa-carrageenan formed thick aggregates that decreased hindrance to PEO diffusion by decreasing the solute kappa-carrageenan concentration in the voids of the aggregated chains, and that iota-carrageenan formed fine aggregates that decreased the solute iota-carrageenan concentration less. ppm in a mixed solution of kappa-carrageenan and iota-carrageenan suggested two possibilities for the microscopic network structure: an interpenetrating network structure, or micro-phase separation.

• 出版日期2016-10-5