金属氧化物多孔薄膜与水溶液界面交互作用机理研究

固液界面交互现象在自然界中广泛存在，金属氧化物与水溶液界面交互作用的研究对于电容去离子技术应用具有重要意义。本项目针对金属氧化物多孔薄膜与水溶液界面交互作用展开分析。通过测量Zeta电位和开路电压表征界面离子浓度和电位分布，研究溶液性质对界面电性质的影响机理，阐明表面电位和空间电荷之间的关联规律。应用椭圆偏振光谱法分析微孔水折射率在不同溶液作用下的变化趋势，通过分子动力学模拟获得微孔水中氢键密度的变化规律，对比实验与模拟结果，揭示溶液性质对微孔水性质的影响机理。基于折射率、介电常数和电容三者之间的物理关系，耦合溶液性质对界面电性质和微孔水性质的影响机理，形成界面交互作用对双电层电容的影响规律。筛选特定的金属氧化物多孔薄膜和选择性吸附离子，构建基于界面交互作用机理的不对称电容去离子结构，实现去离子性能的提升。

Naturally, the interaction of solid liquid interface widely exists. The study of metal oxide and aqueous solution interface is significant to the application of capacitive deionization. This work will be developed on the system of metal oxide porous membrane and aqueous solution. Through the measurement of zeta potential and open circuit potential, the mechanism that the interfacial electrical properties may be influenced by solution chemistry and the relationship between space charge and surface potential can be illustrated. This work will also focus on the varying properties of the pore water under the influence of solution chemistry by characterizing the refractive index with ellipsometer. The experimental results of refractive index and the molecular dynamic simulation results of the hydrogen bond varying with solution chemistry will be compared in order to discuss the mechanism of pore water affected by the interfacial properties. At last, based on the physical relationship among refractive index, dielectric constant and capacitance, different dielectric constants of the metal oxide porous membrane, together with the interfacial electrical properties and the pore water properties, having a coupled influence on the double layer capacitance will be studied. On account of interfacial interaction mechanism of metal oxide porous membrane and aqueous solution depicted above, specific metal oxide porous membrane and specific adsorption ions will be selected and asymmetric capacitive deionization structure will be designed to enhance the deionization performance.