电化学界面处离子分布、静电势和ζ势的研究

Density functional theory is applied to predicting the structures and electrostatic potentials of planar electrochemical surfaces within the framework of the restricted primitive model where small ions are represented by charged hard spheres of equal diameter and the solvent is assumed to be a continuous dielectric medium. The hard-sphere contribution to the excess Helmholtz energy functional is evaluated using the modified fundamental-measure theory and the electrostatic contribution is obtained from the quadratic functional Taylor expansion using the second-order direct correlation function from the mean-spherical approximation. Numerical results for the ionic density profiles and the mean electrostatic potentials near a planar surface of various charge densities are in excellent     

百时香酚兰的液液界面电化学研究

用循环伏安法研究了百里香酚兰在水／硝基苯界面的离子转移行为。根据百里香酚兰在溶液听 离解平衡和电化学性质，讨论了界面离子转移机理，并计算了转移离子的标准转移电位△0^Wψ^0和标准吉布斯转移能△0^WG^0。实验所测半波电位△0^Wψ1／2－pH曲线与理论公式相符。     

新材料的电化学传感界面的设计及其应用研究

电化学传感界面的设计是当前一个活跃的研究领域,尤其是传感界面的研制,能够为今后生命科学以及疾病的治疗提供重要的研究和分析方法。本文在此基础上,探讨了基于新材料的电化学实验,为今后的传感界面研发与应用提供理论支撑。     

离子电解质电化学还原CO_2行为研究

本文通过简单的亲核加成制备出一种新型的离子电解质—1-二乙二醇甲醚基-3-甲基咪唑甘氨酸盐,并对其电化学CO2转化为CO行为进行了研究。研究结果表明,样品可以在较低过电位下实现CO2到CO的转化,并且样品可以重复使用,电化学还原性能不会明显降低。     

百里香酚兰的液液界面电化学研究

用循环伏安法研究了百里香酚兰在水 /硝基苯界面的离子转移行为。根据百里香酚兰在溶液中的离解平衡和电化学性质 ,讨论了界面离子转移机理 ,并计算了转移离子的标准转移电位△ W0 φ0 和标准吉布斯转移能△ W0 G0 。实验所测半波电位△ W0 φ1 /2 —pH曲线与理论公式相符     

基于纳米界面电化学传感器的构建及其应用研究

近年来,构建分析性能更佳的新型电化学传感器的研究与应用已成为传感器研究热点之一。着重探讨了纳米材料在构建新型电化学传感器中的应用,以及纳米界面的构建方法。     

铜离子电化学传感器的构筑与分析

通过将对铜离子(Cu2+)具备良好识别性的有机小分子8-氨基喹啉与纳米金结合,构筑了可用于Cu2+检测的电化学传感器,实现了对溶液中Cu2+的测定。实验中,使用扫描电子显微镜对电极表面的纳米金进行表征。该方法构筑的铜离子传感器在2×10-7~5×10-6mol/L的浓度范围内对Cu2+呈现良好的线性关系,并表现出良好的选择性。     

镧系和锕系元素在离子液体中的配位和电化学行为的研究进展

高温熔盐电解法是干法后处理的研究重点之一,但高温操作对设备要求和能耗极高,限制了该技术的发展。离子液体作为新一代绿色溶剂,在室温下就可得到在高温熔盐中电沉积才能得到的金属和合金,具有操作简便、安全、能耗低等优点,有望代替碱金属氯化物熔盐作为熔盐电解技术的介质应用到干法后处理中。在前人工作的基础上概括介绍了近几年来国内外对镧系和锕系元素在离子液体中的配位和电化学行为的研究成果,并展望未来的研究方向。     

四价铈电化学再生用离子膜选取试验研究

放射性金属进行铈-硝酸化学去污后产生较多的二次废液,电化学再生技术可高效地再生四价铈,使得去污液可循环使用,达到减少二次废液的目的。由于四价铈与硝酸的强氧化性与强腐蚀性,对四价铈电化学再生工艺用离子膜有较高要求。在硝酸体系下依据电化学再生工艺参数进行了离子膜选取试验研究,综合比较了6种离子膜的耐腐蚀性能、机械性能,以及不同离子膜对Ce(IV)再生率、槽电压以及电流效率的影响。结果表明,加强型全氟磺酸离子膜综合性能指标较优,适用于四价铈电化学再生工艺。     

用静电势电荷预测达格列净衍生物溶解度和光谱

基于密度泛函理论(DFT)和密度泛函活性理论(DFRT)和方法(MO6-2X/6-31+G**),利用软件Chemoffice 2004分子建模,用Gaussion 09W软件优化分子结构,用ACD Lab 6.0软件预测新型降糖药达格列净分子及其衍生物分子的水溶液溶解度参数等,优化了16种降糖药达格列净及其衍生物的结构,得到了桥头O原子的密立根电荷(Mul-O),桥头O原子的自然原子轨道电荷(NBO-O),桥头O原子的静电势电荷(ESP-O)和桥头O原子的海秀巴赫电荷(HIR-O)。探讨了常见的10类基组和泛函对ESP电荷值的影响。对比分析其它种类电荷数据发现,桥氧原子的ESP-O电荷与达格列分子及其衍生物水溶液的分子溶解度存在较强烈的线型关系(y=3.699+24.66x,R=0.929)。基于密度泛函理论与方法(DFT B3LYP/sto-3 g),对比展示了药达格列净及其单取代衍生物的三大分子吸收光谱(红外光谱,拉曼光谱和紫外吸收光谱)的差异,并表征了它们的峰位和峰型。     

非水环境中球磨作用对改性SiO2晶体结构、粒度和Zeta电位的影响

以市售SiO2粉体为主要研究对象,采用X射线衍射线形分析、激光粒度分析和Zeta电位分析等表征手段,研究了球磨作用对改性SiO2晶体结构、粒度和Zeta电位的影响. 结果表明,SiO2分别经空气气氛中干磨、以N,N-二甲基甲酰胺(DMF)为球磨分散介质的湿磨、以二甲基甲酰胺(DMF)为球磨分散介质和以硅烷偶联剂KH-560为改性剂的湿磨后,其结构性质有显著差异,分别经过3 h球磨后,干磨、湿磨、添加10%硅烷偶联剂并湿磨和添加20%硅烷偶联剂并湿磨后SiO2平均晶粒尺寸分别为46.9, 31.4, 24.5和75.9 nm,其平均晶格畸变率分别为0.0253%, 0.0871%, 0.117%和0.063%,中位粒径分别为4.241, 1.586, 1.321和5.092 mm.     

Zeta potential study of natural‐ and acid‐activated sepiolites in electrolyte solutions

Detailed characterisation of natural sepiolite from the Eskisehir region of Turkey was performed using X‐ray diffraction, X‐ray fluorescence, field emission scanning electron microscopy, specific surface area (BET method), Fourier transform infrared spectra, derivative thermogravimetry (DTG) and differential thermal analysis. Electrokinetic properties of natural‐ and acid‐activated sepiolites were investigated as a function of the concentration of various electrolytes, such as NaCl, KCl, LiCl, CaCl₂, MgCl₂, NaNO₃, Na₂CO₃, FeCl₃ and Al(NO₃)₃. While mono and divalent cations and anions did not change the surface charge of natural‐ and acid‐activated sepiolite, trivalent cations changed the surface charge from negative to positive. Acid‐activated sepiolite samples shifted towards the positive region in nearly all electrolyte solutions when compared with the natural sepiolite. © 2011 Canadian Society for Chemical Engineering     

蛋白质zeta电位与离子交换层析容量因子的相关性研究

针对蛋白质离子交换层析分离过程预测的困难,选择zeta电位作为中间参数,建立zeta电位与层析容量因子之间的关联.选择牛血清白蛋白(BSA)作为模型蛋白质,考察了pH、离子浓度、离子种类等对蛋白质zeta电位的影响,证实了zeta电位作为蛋白质表面电荷特性表征参数的可行性.以阴离子交换Sepharose FF DEAE为模型层析介质,测定了BSA在不同pH和盐浓度下的容量因子.综合考虑蛋白质和介质两方面因素,选择两者zeta电位乘积(-ζ1×ζ2)作为中间参数,对于不同pH和盐浓度的流动相,(-ζ1×ζ2)与容量因子的对数呈现良好的线性关系,实现了由简便的zeta电位分析预估宏观离子交换层析分离行为的目的,该关联关系的建立将有助于层析分离过程的优化设计.     

经典密度泛函理论在双电层超级电容器研究中的应用

提高储能密度是目前超级电容器研究的重点,它取决于电极材料与电解液界面结构。本文介绍了经典密度泛函理论（CDFT）研究固液界面结构的基本原理以及在多孔电极材料中电解液溶液的热力学和动力学性质研究等进展。CDFT是一种基于统计力学的理论方法,被广泛应用于表界面效应、吸附、溶解等研究,在保证相同计算精度的前提下,具有比分子模拟更高的计算效率。CDFT可以系统地研究多孔材料孔径、孔几何形貌、表面官能团,电解液离子大小、化合价、组成以及溶剂种类、浓度等因素对超级电容器性能的影响,进一步发展考虑反应-传递性质的CDFT,可以为设计新型电极材料和筛选电解液提供理论依据。     

Electrokinetic Properties of Acid-Activated Montmorillonite Dispersions

In this study, the influence of pH, electrolyte concentration, and type of ionic species on the electrokinetic properties (zeta potential and electrokinetic charge density) of the acid-activated montmorillonite mineral have been investigated using the microelectrophoresis method. The electrokinetic properties of acid-activated montmorillonite dispersions have been determined in aqueous solutions of mono-, di-, and trivalent salts and divalent heavy metal salts. Zeta potential experiments have been performed to determine the point of zero charge (pzc) and potential determining ions (pdi). The zeta potential values of the acid-activated montmorillonite particles were negative and did not vary significantly within the pH range studied. Acid-activated montmorillonite dispersions do not have point of zero charge (pzc). The valence of the electrolytes has a great influence on the electrokinetic behavior of the suspension. A gradual decrease in the zeta potential (from ?25 mV to ?5 mV) occurs with the monovalent electrolytes when concentration increased. Divalent and heavy metal electrolytes have less negative z-potentials due to the higher valence of ions. A sign reversal of z-potential has been observed at AlCl₃, FeCl₃, and CrCl₃ electrolytes (potential determining ions) and zeta potential values have had a positive sign at high electrolyte concentrations.

The electrokinetic charge density of acid-activated montmorillonite has shown similar trends for variation in mono- and divalent electrolyte solutions. Up to concentrations of ca. 10^?3 M, it has remained practically constant at approximately 0.5 × 10^?3 C m^?2 For higher concentrations of monovalent electrolytes more negative values (?16 × 10^?3 C m^?2) were observed. It has less negative values in divalent electrolyte concentrations according to monovalent electrolytes (?5 × 10^?3 C m^?2). For low concentrations of trivalent electrolytes, the electrokinetic charge density of montmorillonite particles is constant, but at certain concentrations it rapidly increased and changed its sign to positive.     

沥青质模型油/MD膜驱剂溶液的ζ电势

从分子沉积(MD)膜驱剂与原油活性组分沥青质模型油的ζ电势出发,考察了水相pH、MD膜驱剂质量浓度、盐浓度、沥青质质量浓度、芳香度等对水包模型油乳状液的ζ电势的影响,并进一步探讨了水包油乳状液的稳定性。结果表明,模型油/MD膜驱剂溶液与模型油/水的ζ电势均随pH增加而降低,等电点由2 8变为3 1;模型油/MD膜驱剂溶液的ζ电势随MD膜驱剂质量浓度的增加而增加,MD膜驱剂具有压缩双电层的作用;盐浓度越大,模型油/MD膜驱剂溶液与模型油/水的ζ电势越高;随沥青质质量浓度的增加,ζ电势均有所降低,但质量浓度达到400mg/L后,ζ电势增加;随对二甲苯体积分数增加,模型油/MD膜驱剂溶液与模型油/水的ζ电势均有增大趋势;从总体看,MD膜驱剂的加入能降低沥青质模型油在水中的分散稳定性。     

The Effect of Ionic Strength and pH on the Electrostatic Stabilization of NanoRDX

In this work, 1,3,5‐trinitroperhydro‐1,3,5‐triazine (RDX) with an average crystal size of 300 nm was prepared by bead milling to examine the effect of pH and ionic strength on the Zeta potential. The results showed that nanoRDX has no isoelectric point within the entire range studied ( . The maximum Zeta potential was reached under alkaline conditions of pH 11. The results indicate that the ionic strength, even at low concentrations of NaCl (0.002 mol/L), can increase the Zeta potential of the nanoRDX by 37 %. The Derjaguin‐Landau and Verwey‐Overbeek (DLVO) theory was used to evaluate the stabilization of nanoRDX at different ionic strengths. The Hamaker constant was determined to be 1.84× J and the total potential energy of interaction was computed at different electrolyte concentrations. The DLVO theory predicts that 300 nm RDX particles are stable at a low salt concentration of 0.002 mol/L and unstable at 0.1 mol/L. Turbidity test was conducted for nanoRDX dispersed in a solution of pH 11 and electrolyte concentration (NaCl) of 0.002 mol/L and compared to the nanoRDX dispersed only in water. The turbidity test qualitatively confirmed the results predicted by DLVO theory and Zeta potential measurements, showing that the nanoRDX dispersion was stabilized with the addition of electrolyte in an alkaline solution.     

单层器件分子的设计与密度泛函理论研究

设计了含咔唑、三苯基硼烷的可用来制作单层器件的简单分子9-（4-（diphenylboryl）phenyl）-9H-carbazole（DPPC）,并采用基于第一性原理的密度泛函理论对其基态和激发态以及光谱性质进行了系统研究,结果表明,在DPPC中HOMO、LUMO轨道分布良好,具有良好的空穴传输与电子传输特性。