多聚硼酸锂溶液结构与介稳现象研究

In allusion to the surprisingly complexity of lithium polyborate solutions both structurally and dynamically, we intend to combine the macroscopic description of the structurally sensitive properties, such as pH, conductivity and viscosity etc., with the modern microstructure interpretation in the present project, so as to deepen the understanding of the liquid state of matter, namely, aqueous solutions. Firstly, some change rules of the species distribution and the physical properties in the solutions with concentration, temperature and counterion will be given according to the calculation of chemical species equilibrium and measured pH etc. Secondly，scattering intensities of aqueous solution samples of lithium borates will be accurately measured by a novel X-ray liquid reflectometry with Huber diffractometer in high bright synchrotron radiation facility at 25 and 50℃. Combined with the results of spectroscopy and computer simulation，the intra-molecular distance, coordination number，and their intersection angle of the atom-pair B-O, B-B, and O-O in heteroatomic six-membered-ring anions, the intermolecular distance and coordination number of B-W and O-W in the first hydration shell of borate anions and Li-W(Ⅰ) and Li-W(Ⅱ) in the first and the second coordination shell of Li+ ion, the characteristic distance and the coordination number of Li-B in contact ion pair will be quantitatively calculated by geometric models. The nature of the metastable phenomenon of aqueous lithium borate solutions can be exposed from macroscopical to microscopical profiles so that provide a theoretical support at a molecular level for exploitation of borate chemicals in Qinghai-Tibet Plateau salt lake bittern.

针对硼酸锂溶液具有结构和动力学两方面复杂性的特点，采用宏观性质（如电导、黏度和pH等结构敏感性质）描述结合现代微观结构解释，加深对硼酸盐锂溶液这一基本物态的认识。首先根据pH与溶液中存在的各物种的化学平衡关系计算给出溶液中物种分布和物化性质随浓度、温度和阳离子的变化规律。其次用同步辐射装置Huber衍射仪反射法测定25℃ 和50℃给定浓度下硼酸锂溶液样品的散射数据，结合光谱学和计算机模拟结果，通过几何模型定量计算分别给出溶液中杂原子六元环阴离子内B-O、B-B和O-O距离、配位数和夹角，阴离子第一水合层B-W（水）和O-W距离和配位数，阳离子第一和第二水合层Li-W(I)和Li-W(II)距离和配位数，接触离子对Li-B特征距离和配位数。从宏观和微观两个侧面揭示硼酸锂溶液介稳现象的本质，为青藏高原硼酸盐类型盐湖开发利用提供分子水平的理论依据。

针对硼酸锂溶液具有结构和动力学两方面复杂性的特点，采用宏观性质（如电导、黏度和pH等结构敏感性质）描述结合现代微观结构解释，加深对四硼酸锂溶液这一基本物态的认识。首先根据pH与溶液中存在的各物种的化学平衡关系计算给出溶液中物种分布和物化性质随浓度、温度和阳离子的变化规律。其次用同步辐射装置Huber衍射仪反射法测定25℃ 和50℃给定浓度下硼酸锂溶液样品的散射数据，结合光谱学和计算机模拟结果，通过几何模型定量计算分别给出溶液中杂原子六元环阴离子内B-O、B-B和O-O距离、配位数和夹角，阴离子第一水合层B-W（水）和O-W距离和配位数，阳离子第一和第二水合层Li-W(I)和Li-W(II)距离和配位数，接触离子对Li-B特征距离和配位数。从宏观和微观两个侧面揭示硼酸锂溶液介稳现象的本质，为青藏高原硼酸盐类型盐湖开发利用提供分子水平的理论依据