A thermoreversible double gel: Characterization of a methylcellulose and κ-carrageenan mixed system in water by SAXS, DSC and rheology

Sol–gel and gel–sol thermal transition of methylcellulose/water, κ-carrageenan/water and methylcellulose/κ-carrageenan/water mixtures was investigated utilizing small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC) and oscillatory rheological experiments in temperature regime from 20 to 80 °C. Methylcellulose (E461) and κ-carrageenan (E407) are well-known additives used for gelation in various nutrition and other products. The formulation and characterization of a mixed thermoreversible methylcellulose/κ-carrageenan/water gel with very interesting double thermal transition gel–sol–gel upon heating was possible. This specific thermal behavior provides a liquid state of the system between the low-temperature and high-temperature gel-state and at the same time allows for the easy temperature tuning of the system's state. As such this system is suggested to be further tested as potential carrier for various functional colloidal systems.

Graphical abstractGel–sol–gel transitions of thermo-reversible aqueous κ-carrageenan and methylcellulose solutions and mixtures thereof were characterized utilizing SAXS, DSC and rheology. Example: 2 wt% of 1:1 polymer mixture in water.Figure optionsDownload full-size imageDownload as PowerPoint slide