AI 中文总结
本研究建立二元液体混合物双电层热力学理论，发现斯特恩层电容随局部溶剂组成变化可产生负微分电容及双电层一级相变，其理论与四丁基氯化铵混合溶剂电容数据半定量吻合，揭示斯特恩层溶剂交换对相关性质的调控作用。
AI 中文摘要
我们建立了二元液体混合物中双电层的热力学理论，该理论考虑斯特恩层电容依赖于局部溶剂组成。这种耦合会对逆微分电容产生额外的负贡献，导致表面电势成为表面电荷密度的非单调函数，进而产生负微分电容以及电压诱导的双电层两种状态之间的一级相变。我们采用表面电荷控制的巨势的公共切线构造确定共存条件，得到以斯特恩电容对比度、表面电荷密度、本体组成和表面电势为变量的相图。我们还将该理论与四丁基氯化铵在水/1-丙醇混合物中的电容数据进行比较，发现在连续响应区存在半定量一致性。这些结果表明，斯特恩层内的溶剂交换可强烈控制二元混合物的电容和界面相行为。
英文摘要
We develop a thermodynamic theory of electric double layers in binary liquid mixtures by allowing the Stern-layer capacitance to depend on the local solvent composition. This coupling produces an additional negative contribution to the inverse differential capacitance. As a result, the surface potential can become a nonmonotonic function of the surface charge density, leading to negative differential capacitance and a voltage-induced first-order transition between two electric-double-layer states. We determine the coexistence condition using a common-tangent construction for the surface-charge-controlled grand potential and obtain phase diagrams in terms of the Stern-capacitance contrast, surface charge density, bulk composition, and surface potential. We also compare the theory with capacitance data for tetrabutylammonium chloride in water/1-propanol mixtures, finding semi-quantitative agreement in the continuous-response regime. These results suggest that solvent exchange inside the Stern layer can strongly control the capacitance and interfacial phase behavior of binary mixtures.
Comments7 pages, 4 figures
