硫酸钾溶液结构的X射线散射和Raman光谱的研究  

Study on the Structure of K_2SO_(4) Aqueous Solutions by X-Ray Scattering and Raman Spectroscopy

作　　者：王美玲 李非[1,2,3,4] 王旭阳 朱含钰 乔梦丹 袁俊生 WANG Mei-ling;LI Fei;WANG Xu-yang;ZHU Han-yu;QIAO Meng-dan;YUAN Jun-sheng(School of Chemical Engineering,Hebei University of Technology/Engineering Research Center for Chemical Technology of the Efficient Utilization of Seawater Resources,Tianjin 300130,China;Collaborative Innovation Center of Hebei Modern Marine Chemical Technology,Tianjin 300130,China;School of Chemical Engineering,Hebei University of Technology/Chemical Energy Conservation Process Integration and Resource Utilization National-Local Joint Engineering Laboratory,Tianjin 300130,China;Tianjin Key Laboratory of Chemical Process Safety,Tianjin 300130,China)

机构地区：[1]河北工业大学化工学院/海水资源高效利用化工技术教育部工程研究中心,天津300130 [2]河北省现代海洋化工技术协同创新中心,天津300130 [3]河北工业大学化工学院/化工节能过程集成与资源利用国家-地方联合工程实验室,天津300130 [4]天津市本质安全化工技术重点实验室,天津300130

出　　处：《光谱学与光谱分析》2023年第6期1838-1845,共8页Spectroscopy and Spectral Analysis

基　　金：河北省自然科学基金项目(E2020202020);河北省高等学校科学技术研究项目(QN2019048);国家重点研究发展计划项目(2016YFB0600504);教育部创新团队发展计划项目(IRT14R14);河北省现代海洋化工技术协同创新中心项目(冀教科[2013]37号);基于工学并举的“海水提钾”一体化教学资源构建(202002046010);基于科教融合的海洋技术专业教学资源构建及应用探索(2020GJJG029)资助。

摘　　要：钾是海水中的常量元素之一,硫酸钾水溶液结构研究有利于解释其溶解度的微观机理,从而为海水中钾盐的分离纯化提供理论指导。利用实验室改装的X射线衍射仪、上海同步辐射光源装置及拉曼光谱技术研究了不同质量分数的K_(2)SO_(4)水溶液的微观结构信息。由X射线散射数据处理得到的差值结构函数F(Q)可知,Q=2.5A^(-1)附近的一高一低双峰逐渐变成强度相当的两个峰,此处双峰与水溶液中的氢键网络结构有关;随着质量分数的增加,Q=5.0?^(-1)附近的峰位向坐标轴右侧移动。由G(r)可知,2.8A处峰随质量分数的增加有展宽趋势,主要受O—O相互作用影响。在拉曼光谱图中,位于3200 cm^(-1)附近的肩峰强度随溶质含量的增加逐渐降低,2800~3800 cm^(-1)范围内整体峰形变窄。拉曼光谱去卷积拟合的结果表明,K_(2)SO_(4)的加入破坏了水的四面体氢键构型,小幅促进了质子供体型氢键的形成。X射线散射和拉曼光谱的分析结果均说明K_(2)SO_(4)的加入破坏了原有的水分子四面体网络结构。Potassium is one of the major elements in seawater.Research on the structure of potassium sulfate aqueous solution is helpful in explaining the microscopic mechanism of its solubility,thereby providing theoretical guidance for the separation and purification of potassium salt in seawater.In this paper,the microstructure of K_2SO_(4) aqueous solution with different mass fraction was studied using an X-ray diffractometer refitted in the laboratory,Shanghai Synchrotron Radiation Facility device and Raman spectroscopy.The F(Q)obtained from the processing of the X-ray scattering data shows that the double peak near Q=2.5-1 gradually becomes two peaks of equal intensity,which is associated with the hydrogen bonded network in the liquids.As the mass fraction increases,the peak position near Q=5.0-1 moves to the right of the coordinate axis.It can be seen from G(r)that the peak at 2.8 tends to broaden with the increase of the mass fractions,which is mainly affected by the O—O interaction.In the Raman spectrum,the intensity of the shoulder peak near 3200 cm^(-1) gradually decreases with the increase of solute content,and the overall peak shape becomes narrower in the range of 2800~3800 cm^(-1).The results of deconvolution fitting of Raman spectra show that adding K_2SO_(4) destroys the tetrahedral hydrogen bond configuration of water and slightly promotes the formation of proton-donor hydrogen bonds.The analysis results from X-ray scattering and Raman spectroscopy indicated that the addition of K_2SO_(4) destroyed the original tetrahedral network structure of water molecules.

关 键 词：溶液结构 X射线散射 拉曼光谱 K_(2)SO_(4) 

分 类 号：O661[理学—分析化学]