Rheological and thermal properties of agarose aqueous solutions and hydrogels

Abstract

In this article, we report on the rheological properties of agarose aqueous solutions and gels. Viscosity curves were determined for homogeneous agarose aqueous solutions at different temperatures (from 68 to 38 8C) to study the viscosity behavior as the systems undergo gelation. The gelation phenomenon of agarose solutions was also investigated by shear oscillation experiments and differential scanning calorimetry. The gelation and melting temperature as a function of agarose concentration were determined together with the gelation and melting enthalpies. The results obtained were interpreted using the two-step model describing the gelation of agarose in water.

New hydrogels based on the interpenetration of physical gels of agarose and chemical gels of polyacrylamide

“…The evolution of the elastic modulus with frequency is the characteristic of gelled systems (solid-like behavior, with G' being nearly independent of frequency). The same behavior is observed for pure agarose hydrogels [18]. Therefore, frequency sweeps do not supply any further proof for the interpenetration of agarose and PAAm.…”

“…Gain of understanding in the gelation mechanism of agarose has been subject of many scientific publications, justified by its importance as typical model for gelling materials, as texture modifier in the food industry, or as bacterial medium in the biomedical field, [17,18].…”

Supramolecular Nanofibrillar Polymer Hydrogels

“…Experiments are generally performed at low strains and frequencies to avoid significantly disturbing the gelation process and gel structure. In the course of gelation, the values of G 0 and G 00 vary and, according to the generally accepted Winter-Chambon criterion [193], the gel point is reached when tan δ becomes independent of the oscillatory frequency [194].…”

Supramolecular Polymer Networks: Preparation, Properties, and Potential

“…The most important representatives are polysaccharides such as cellulose [159,160], starch [161], agarose [162,163], and dextran [164,165], the physical cross-linking of which occurs via hydrogen bonding of their hydroxy groups.…”