论文标题
局限纳米孔中的深共晶溶剂：热力学和化学活动的洞察力
Confining deep eutectic solvents in nanopores: insight into thermodynamics and chemical activity
论文作者
论文摘要
我们已经确定了原型深的共晶溶剂乙胺（乙二醇 /胆碱氯化物2：1）的详细相图，作为水分水平的函数，在块状状态下，并限制在介质的多孔硅矩阵MCM-41和SBA-15和sba-15和pore nm $ $ $ $ $ $ $ $ $ $ radi。对于整齐和中等水分的DES，避免了冷冻，并在所有情况下均形成玻璃化溶液。对于高于阈值$ w_g'\ of约30 \％$的质量分数，发生结晶并导致形成最大冻结的浓缩DES溶液。在这种情况下，由于监禁和冷冻镜的结合，在狭窄状态下达到了极深的熔化凹陷。这些现象是根据经典吉布斯 - 汤姆森（Gibbs-Thomson）和劳尔特（Raoult）热力学方法的扩展版本进行定量分析的。在此框架中，被限制系统中水化学活性的预测值显示出系统地偏离散装对应物的化学活性。讨论了“无人土地”中水的热力学异常，以及在纳米渠道或与固体接口处操纵时，讨论了水中水的热力学异常。
We have established the detailed phase diagram of the prototypical deep eutectic solvent ethaline (ethylene glycol / choline chloride 2:1) as a function of the hydration level, in the bulk state and confined in the nanochannels of mesostructured porous silica matrices MCM-41 and SBA-15, with pore radii $R_P$ = 1.8 nm and 4.15 nm. For neat and moderately hydrated DESs, freezing was avoided and glassforming solutions were formed in all cases. For mass fraction of water above a threshold value $W_g'\approx30\%$, crystallization occurred and led to the formation of a maximally-freeze concentrated DES solution. In this case, extremely deep melting depressions were attained in the confined states, due to the combination of confinement and cryoscopic effects. These phenomena were analyzed quantitatively, based on an extended version of the classical Gibbs-Thomson and Raoult thermodynamic approaches. In this framework, the predicted values of the water chemical activity in the confined systems were shown to systematically deviate from those of the bulk counterparts. The origin of this striking observation is discussed with respect to thermodynamic anomalies of water in the 'no-man's land' and to the probable existence of specific nanostructures in DES solutions when manipulated in nanochannels or at interfaces with solids.
