Effect of Agarose Content on the Thermal, Rheological, and Electrochemical Properties of Proline: Glycerol-based Eutectogels

Abstract

Deep eutectic solvent (DES)-based eutectogels combine the physicochemical characteristics of DESs with the structural properties of polymeric networks. In the present study, a proline DES with a 1:3 molar ratio was incorporated into agarose to prepare eutectogels with different agarose contents. Two formulations were investigated using 50 g and 100 g of agarose per 100 g of DES, respectively. The prepared eutectogels were characterized by thermogravimetric analysis (TGA), rheological measurements, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) to investigate their thermal, viscoelastic, flow, and electrochemical behaviour. TGA showed initial mass loss associated with volatile/moisture components followed by major thermal degradation at higher temperatures. Rheological measurements showed that the storage modulus (G′) remained higher than the loss modulus (G″) for both formulations, indicating predominantly elastic and gel-like behaviour. The higher agarose-content formulation exhibited greater G′ and viscosity, while both eutectogels showed shear-thinning behaviour. CV measurements demonstrated measurable electrochemical responses, with the 50% eutectogel showing a higher current at +1 V (3.7 μA) than the 100% eutectogel (0.93 μA). EIS measurements provided complementary information on the resistive and interfacial behaviour of the eutectogels. Overall, the results demonstrate that variation in agarose content can influence the thermal, rheological, and electrochemical behaviour of proline eutectogels, providing a basis for further optimization of DES–biopolymer systems.

Abstract as supplied by the indexing source. © the authors / publisher.