Direct observation of reversible liquid–liquid transition in a trehalose aqueous solution

Abstract

Significance Recent studies on liquid water suggest that the two liquid waters exist in the supercooled temperature region and that their existence relates to the anomalous behavior of low-temperature liquid water such as the maximum density at 4 °C. However, the experimental investigation of two liquid waters is difficult because of the rapid crystallization. In this study, a reversible liquid–liquid transition in a trehalose aqueous solution by the change in pressure was observed directly. This result suggests strongly that two liquid waters exist in the aqueous solution. This study has implications for wide fields related to liquid water, such as solution chemistry, cryobiology, meteorology, and food engineering.