Low-temperature Characterization of Sugar Alcohol-based Type V Deep Eutectic Solvents for Anti-icing and Cryopreservation Applications.

In this study, sugar alcohol-based Type V deep eutectic solvents (DESs) were prepared and characterized for potential applications in anti-icing and cryopreservation. Physicochemical analysis revealed that sugar alcohol-amino acid DESs were marginally more basic than sugar alcohol-sugar DESs. All of the neat DESs reported low water activities, suggesting the possibility of strong water interactions. Thermophysical characterization using differential scanning calorimetry (DSC) showed that the glass transition temperature increased with the molecular weight of the sugar alcohol component. High glass transition temperatures across dilutions highlighted their suitability for cryopreservation by vitrification. Melting points of the DESs increased with dilution but remained lower than ideal mixtures. Low melting temperatures combined with their significantly lower enthalpies of fusion compared to pure water underscored the attractiveness of these diluted DESs for anti-icing and conventional cryopreservation. Low-temperature Raman spectroscopy revealed differences in ice suppression for sugar and amino acid-containing DESs at different dilutions, with sugar-sugar alcohol DESs performing better at low dilutions and amino acid-sugar alcohol DESs performing better at high dilutions. Analyzing the ice crystal morphologies found that the diluted DESs exhibited reduced ice crystal size compared to pure water, indicating their ice-controlling ability. A preliminary sustainability assessment of these Type V DESs supported their alignment with green chemistry principles, highlighting Type V DESs as effective and sustainable ice-controlling agents for both anti-icing and cryopreservation.