在室溫下，研究了由氯化膽鹼和檸檬酸一水合物（CA）混合而成的深共熔溶劑（DES）在不同摩爾比下的過冷液體狀態。這種過冷的DES都非常穩定，其黏度皆超過104 mPa∙s，而且隨著CA含量的上升而增加。黏度對溫度的依賴性可以用阿瑞尼斯方程描述，其中活化能會隨著CA含量的增加而增加。由於其黏度極高，因此在使用懸滴法測量表面張力時，需要採用逐步加壓的方法，且液滴從鬆弛至達到平衡的過程非常緩慢。發現其表面張力非常高，與水相當，並且隨著CA濃度的增加，表面張力略有下降。過冷之DES在玻璃上的潤濕行為以異常緩慢的擴散過程為特徵。其平衡接觸角會隨著CA含量的上升而增加。此外，還研究了此過冷DES形成之液態橋梁在不同表面之間的潤濕競爭，有趣的是發現最終結果不僅取決於表面濕潤性，還取決於接觸時間。;The supercooled liquid state of a deep eutectic solvent (DES) composed of a mixture of choline chloride and citric acid monohydrate (CA) is studied for different molar ratios at room temperature. The supercooled DESs are highly stable and exhibit viscosities exceeding 104 mPa∙s, which increase with higher CA content. The dependence of the viscosity on temperature can be described by the Arrhenius equation, where the activation energy increases with CA content. Due to extremely high viscosity, the surface tension measurement using the pendant drop method requires a stepwise pressurization approach, and the relaxation to equilibrium is quite slow. Surface tensions were found to be considerably high, comparable to that of water, and they slightly decrease with higher CA concentration. The wetting behavior of supercooled DESs on glass is characterized by an unusually slow spreading process. The equilibrium contact angle increases with higher CA content. Moreover, wetting competition of a liquid bridge between dissimilar surfaces was also examined, and it is interesting to find the outcome dependent on the contact time, in addition to surface wettability.
