五硼酸铷溶液的物化性质及物种分布

碳酸铷、硼酸化学计量比混合，蒸发溶液，直至五硼酸铷RbB5O8·4H2O晶体析出。经粉末X射线衍射（XRD）、拉曼光谱（Raman spectroscopy）、热重/微商热重/差示扫描量热（TG/DTG/DSC）、原子吸收光谱等实验方法，确定其化学组成及结构。298.15、333.15K时测量溶液的物理化学性质（密度、电导、pH），并与经验方程进行拟合，研究五硼酸铷溶液的物化性质随浓度、温度的变化规律。根据文献报道的平衡常数，实验测量的pH数据，采用牛顿迭代法进一步研究五硼酸铷溶液中主要存在的硼酸根离子对类型、含量以及物种的形成。

The Physicochemical Properties and Species Distribution of The Aqueous Rubidium Pentaborate solutions

Hydrated rubidium pentaborate was precipitated via evaporating solution of rubidium carbonate and boric acid in stoichiometric proportions. The chemical composition and structural information about the synthesized compound were achieved using different methods of powder X-ray diffraction, Raman spectroscopy, TG/DTG/DSC and atomic absorption spectroscopy. Physicochemical property data, including density, electrical conductivity and pH data of aqueous hydrated rubidium pentaborate solutions, have been accurately determined at temperature of 298.15 and 333.15K, respectively. Furthermore, the empirical equations were used to fitting with the obtained experimental data. On the basis of these, the change rules were investigated in aqueous rubidium pentaborate solutions about the physicochemical properties when temperature and solution concentration varied. According to the equilibrium constants reported in literature and experimental pH data, besides, the type of different borate anions, content, and the speciation among different borate anions occurred in solution were studied by Newton iteration.