聚电解质材料—（I）复合体系溶液中相互作用的研究进展

聚电解质材料兼有高分子长链和小分子电解质电离的双重结构特征。文中在介绍溶液中聚电解质与小分子盐、表面活性剂以及带相反电荷聚电解质相互作用的基础上，讨论溶液中聚电解质复合体系相互作用的主要影响因素，以期为聚电解质的实际应用和理论研究提供参考。     

聚电解质材料——(Ⅰ)复合体系溶液中相互作用的研究进展

聚电解质材料兼有高分子长链和小分子电解质电离的双重结构特征。文中在介绍溶液中聚电解质与小分子盐、表面活性剂以及带相反电荷聚电解质相互作用的基础上,讨论溶液中聚电解质复合体系相互作用的主要影响因素,以期为聚电解质的实际应用和理论研究提供参考。     

在线电导率监视仪校准方法初探

在电解质的溶液中，带电离子在电场的影响下产生移动而传递电子，因此具有导电作用，其导电能力的强弱称为电导度S。因为电导是电阻的倒数，因此，测量电导大小的方法可用两个电极插入溶液中，以测出二极间的电阻尺，根据欧姆定律，温度一定时，这个电阻值与电极间距L（cm）成正比，与电极的截面积A（cm2）成反比。即     

关于电导率仪中温度补偿的讨论

<正>一、前言众所周知,溶液的电导率与温度密切相关,因为温度发生变化时,电解质的电离度、溶解度、离子迁移速度、溶液黏度等都会发生变化,电导率也会变化。温度升高,电导率增大。电导率仪的温度补偿就是为了克     

LaF3（掺杂CaF2）固体电解质湿度传感器

用LaF3（掺杂CaF2）小管作为固体电解质，分别以H2C2O4·2H2O、H2C2O4混合物和Na2SO4·10H2O、Na2SO4混合物作为参比电极，用已知水蒸气分压的纯水和KOH溶液作为工作电极，构成了两类固体电解质水蒸气浓差电池。分别在8～33℃和6～24℃温度范围内研究了电池电动势与温度的关系，得出了有规律性的结果。即电池的电动势随温度的升高而变小，在温度恒定的情况下，随工作电极水蒸气分压的增大而变大，在EMF和lg（PH2O（Ⅰ）PH2O（Ⅱ））之间有较好的线性关系，可望成为一种固体电解质型的新式湿度传感器。     

溶剂组成对尖晶石LiMn2O4正极材料电化学性能的影响

使用恒电流充放电和粉末微电极循环伏安方法研究了尖晶石LiMn2O4正极材料在不同混合溶剂的电解质溶液中的电化学性能，结合溶剂组分和电解质溶液的理化特性,探讨了影响尖晶石LiMn2O4正极材料电化学性能的溶剂因素。研究表明，电解质溶液组分在电极导电剂表面的氧化电位是决定LiMn2O4电极在其中的电化学循环性能的重要因素。在满足一定的氧化电位的前提下，LiMn2O4初始放电容量与电解质溶液的电导率大小有关。     

聚乙烯醇/聚丙烯酸水凝胶的电刺激响应性研究

通过冰冻－解冻循环方法制备了机理交联水凝胶聚乙烯醇（PVA）／聚丙烯酸（PAA），研究了该水凝胶在直流电场作用下的弯曲响应性质，考察不同浓度和组成的凝胶在0．01mol/L Na2Co3电解质水溶液中，。作用电场的电场强度对凝胶弯曲速率的影响，以及电解质溶液的浓度对凝胶弯曲速率的影响，初步探索了凝胶在电场作用下的弯曲机理。     

聚合物P(NIPAM-AM-NPA)的合成及溶液性能

以丙烯酸壬基酚聚氧乙烯酯(NPA)、丙烯酰胺、N-异丙基丙烯酰胺为单体,采用自由基水溶液聚合方法制备了水溶性共聚物P(NIPAM-AM-NPA)。采用FT-IR、1H-NMR对该共聚物以表征;研究了共聚物浓度、温度以及不同电解质对共聚物溶液性能的影响。结果表明,随着盐浓度的增加,聚合物溶液表观黏度有较大幅度上升。在相同情况下,NaCl的增粘效果最为显著,而MgCl2和CaCl2则影响不大。该共聚物的盐水溶液在升温条件下可保持良好的增粘作用,适当条件下还会出现黏度随温度升高而上升的独特现象。     

双草酸硼酸锂制备工艺条件的优化

采用固相法合成了锂离子电池电解质锂盐双草酸硼酸锂(LiBOB)。考察了制备条件对产品纯度和结晶度的影响,由此得出,固相法制备LiBOB的最佳工艺条件为:预保温温度为100℃,预保温时间为6h,加热温度为260℃,加热时间为2h。优化条件下所得产品的纯度高,晶格内粒子的排列紧密,结晶度达到了82.8%。通过对电解质溶液电导率的测定表明,优化条件下所得LiBOB的电解质溶液具有较高的电导率。     

聚砜中空纤维超滤膜的流动电位研究

通过对聚砜中空纤维超滤膜在不同电解质溶液中的膜表面流动电位的研究,考察了膜两侧压差、电解质浓度及离子价态及溶液pH对流动电位的影响,用Helmoltz-Schmoolukovski方程与Gouy-Chapmann方程计算了膜面电荷密度,测定了污染膜经不同清洗剂清洗后的流动电位和水通量.结果表明,流动电位绝对值随电解质浓度的增大而减小;同样电解质浓度下,阳离子价态越高,流动电位绝对值越小.溶液pH对流动电位影响较大,当溶液pH超过等电点时,流动电位绝对值随溶液pH的增加而增加.在一定电解质浓度范围内过滤电解质溶液时,流动电位和通量的衰减幅度不同,对含高价阳离子的电解质溶液,流动电位的衰减比通量衰减更明显.     

Some fundamental analogies between solid,molten and aqueous materials: application of the concepts of energy levels and the band theory of solids

An interaction of electrochemical ideas with the approaches of solid state physics provides some interesting analogies and themes in which certain aspects of electrolyte solutions, solid semiconductors and ionic liquids can be discussed in a somewhat inter-related manner. Some of the fundamental properties of this wide range of materials (solid semiconductors, molten salts or aqueous (electrolyte) solutions) may be unified into a loose theme derived from the general notions of the band theory of solids and its analogue in electrolyte solutions, namely, the electron and proton levels of electrolytes. The concepts which would describe the intermeshing behaviour of these materials will be derived from: the band theory of semi-conductors; Gurney's ideas on the occupied and vacant proton levels in electrolyte solutions; Rose's approach to the electron energy levels in solids and electrolytes; Fuller's views on the conceptual analogies between semiconductors and electrolyte solutions; interpretation of molten salts put forward by Bockris and co-workers; and, finally, the industrial applications of Gurney's ideas made by Vermilyea in his interpretations of the corrosion of aluminium in water and the effect of various inhibitors on this corrosion reaction.     

Measuring interparticle forces: Evaluation of superplasticizers for microsilica via colloidal probe technique

Recent concretes like ultra-high performance concrete (UHPC) are comprised of large quantities of fines following a well-defined gradation to fill the voids between coarser particles, such as cement grains. The filling of voids displaces water, which positively influences the flowability. As the rheological properties of these fresh concretes depend mainly on the forces acting between the fines due to their high specific surface areas, understanding of these forces has become crucial. In this study, the atomic force microscopy technique of colloidal probes has been used to study the adhesive forces acting between individual silica particles placed in superplasticizer and electrolyte solutions, as silica exhibit the largest fraction of inner surface in common UHPC mixtures. Pairs of individual amorphous glass particles were approached and retracted from each other. Using this technique and silica particles as a model system, several commercial superplasticizers could be evaluated regarding their influence on the interparticle adhesion.     

An electrochemical route to graphene oxide

Large-scale graphene oxide (GO) with adjustable resistivity was synthesized from graphite via an electrochemical method using KCl solution as an effective electrolyte. During the exfoliation process, electrostatic force intercalates chloride ions between the expanded graphite layers on the anode. These chloride ions form small gas bubbles between the graphite layers in the electrochemical reaction. It is believed that the gas bubbles expand the gap between graphite sheets and produce a separating force between adjacent graphene layers. This separating force overcomes the Van der Waals force between adjacent sheets and exfoliates graphene layers from the starting graphite. Because the graphene is electrochemically oxidized by chorine during the exfoliation, the exfoliated GO sheets are hydrophilic and easily dispersed in the electrolyte solution. The GO solution prepared by the electrochemical exfoliation can be simply sprayed or spin-coated onto any substrate for device applications. The measured average thicknesses of a monolayer, bilayer, and trilayer exfoliated GO on SiO2 substrate were 1.9, 2.8, and 3.9 nm, respectively. It was observed that the measured resistance of the exfoliated GO sheets increases due to electrochemical oxidation in the solution. This electrochemical approach offers a low-cost and efficient route to the fabrication of graphene based devices.     

Differential ion transport induced electroosmosis and internal recirculation in heterogeneous osmosis membranes

Water and ion transport through a heterogeneous membrane separating two electrolyte solutions at different concentrations is investigated by using molecular dynamics simulations. The membrane features pairs of oppositely charged pores with identical diameters. Simulation results indicate that the differential transport of K(+) and Cl(-) ions through the membrane pores creates an electrical potential difference across the membrane, which then induces an electroosmotic water flux. The induced electroosmosis creates an internal recirculation loop of water between adjacent pores. The implications of these new observations are discussed.     

An investigation into the structure of aqueous NaCl electrolyte solutions under magnetic fields

Molecular dynamics simulations are performed to investigate the effects of magnetic fields with intensities of 1–10 T on aqueous NaCl electrolyte solutions at 298 K. The simulations employ the F3C (flexible three centered) water model and investigate electrolyte solutions with both low (1 M) and high (5 M) NaCl concentrations. The results show that the self-diffusion coefficient of the water molecules decreases in a low-concentration solution as the magnetic field intensity is increased, but increases in a high-concentration solution. The magnetic field enhances the mobility of the Na⁺ and Cl⁻ ions in both low- and high-concentration solutions. The average number of hydrogen bonds increases when the magnetic field is applied to pure water or to a solution with a low NaCl concentration, but decreases in a solution with a high-concentration. The results show that the enhanced mobility of the ions under a magnetic field causes serious damage to the hydrogen bond network in the high-concentration solution. Conversely, in the low-concentration solution, the structural behavior is dominated by the properties of the water molecules, and hence the hydrogen bonding ability is enhanced as the magnetic field is increased.     

Soft but Powerful Artificial Muscles Based on 3D Graphene–CNT–Ni Heteronanostructures

Bioinspired soft ionic actuators, which exhibit large strain and high durability under low input voltages, are regarded as prospective candidates for future soft electronics. However, due to the intrinsic drawback of weak blocking force, the feasible applications of soft ionic actuators are limited until now. An electroactive artificial muscle electro‐chemomechanically reinforced with 3D graphene–carbon nanotube–nickel heteronanostructures (G–CNT–Ni) to improve blocking force and bending deformation of the ionic actuators is demonstrated. The G–CNT–Ni heteronanostructure, which provides an electrically conductive 3D network and sufficient contact area with mobile ions in the polymer electrolyte, is embedded as a nanofiller in both ionic polymer and conductive electrodes of the ionic actuators. An ionic exchangeable composite membrane consisting of Nafion, G–CNT–Ni and ionic liquid (IL) shows improved tensile modulus and strength of up to 166% and 98%, respectively, and increased ionic conductivity of 0.254 S m^?1. The ionic actuator exhibits enhanced actuation performances including three times larger bending deformation, 2.37 times higher blocking force, and 4 h durability. The electroactive artificial muscle electro‐chemomechanically reinforced with 3D G–CNT–Ni heteronanostructures offers improvements over current soft ionic actuator technologies and can advance the practical engineering applications.     

Electrokinetic and adsorption properties of sepiolite modified by 3-aminopropyltriethoxysilane

Surface modification of clay minerals has become increasingly important for improving the practical applications of clays such as fillers and adsorbents. An investigation was carried out on the surface modification of sepiolite with aminopropylsilyl groups in 3-aminopropyltriethoxysilane (3-APT). The zeta potential of the modified sepiolite suspensions was measured as a function of initial electrolyte concentration and equilibrium pH using a Zeta Meter 3.0 for modified sepiolite. The utility of the 3-APT-modified sepiolite was investigated as an adsorbent for removal of various heavy metal ions such as Fe, Mn, Co, Zn, Cu, Cd and Ni from aqueous solutions. The effects of various factors on the adsorption, such as pH, ionic strength and temperature of the solution were studied. The results showed that the amount adsorbed increases with solution pH in the pH range of 1.5 and 7.0; indicated that the modified sepiolite adsorbed Fe and Mn ions more than other metal ions such as Co, Zn, Cu, Cd and Ni. It was found that the temperature had an important effect on metal ion adsorption by the modified sepiolite. The adsorption isotherm has been determined and data have been analyzed according to the Langmuir and Freundlich models.     

Versatile flow-injection amperometric ion detector based on an interface between two immiscible electrolyte solutions: numerical and experimental characterization

The present paper describes a flexible thin layer electrochemical flow cell for ultrasensitive amperometric detection at a supported interface between immiscible electrolyte solutions. Nanomolar detection limits were demonstrated using the cell design, and 3D finite element simulations allowed a detailed characterization of the flow cell. The cell design employed in the present work allowed the sensing oil membrane and the aqueous reference electrode to be placed in close contact, thereby minimizing cell resistance. The adjustable cell volume means that the same cell design can be used for different application with different requirement for detection limits and dynamic range. A disposable membrane was employed which reduces the need for surface cleaning and prevents sample carryover between different applications. For the lowest cell volumes the detection chamber approaches a thin layer electrochemical flow cell detector with a large surface to volume ratio.     

The Zeta Potential Op Droplets Prepared from a Self-Emulsifying Oil

The zeta potential of droplets formed by the self emulsification of compositions of n-hexane, phosphated nonylphenol ethoxylate and phosphated fatty alcohol ethoxylate has been determined in water and aqueous electrolyte solutions over a pH range of 3-11. Anomalies may be noted as a function of the n-hexane concentration of the surfactant/oil composition added to water. This, it is suggested, may be related to the mesomorphic systems that occur in bulk composition/water mixtures and could form at the interface of the droplets in water.

Effects on the electrophoretic/mobility observed in the presence of sodium, lithium, calcium or magnesium may be explained by the relative size of the sphere of hydration around the cat ion that controls the depth of penetration through the surface layers of the droplets.

Aluminum ions appear to react completely with the surfactant phosphate moiety, precipitating directly onto the droplet surface. The droplet surface charge always remains negative and below 30 mV except in the presence of aluminum ions. The maximum charge is obtained at the pH of 5.5 which approximates to the pKa₁ Df the surfactant mixture.     

Electrochemically modulated liquid-liquid extraction of ions

The development of ion extraction methods under electrochemical control via electrochemistry at the interface between two immiscible electrolyte solutions is discussed. A hydrodynamic flow injection system was used for the potentiostatic extraction of non-redox-active species from a flowing aqueous phase into a stationary organogel phase. The ions tetraethylammonium, 4-octylbenzenesulfonate (4-OBSA-), and p-toluenesulfonate (p-TSA-) were studied as model analytes. The extraction study comprised examination of the influence of extraction potentials, aqueous-phase flow rate, and target species concentration. The extraction process can be monitored in situ by means of the ion-transfer current, which has opposing signs for anions and cations. Hydrodynamic voltammograms were obtained from these experiments. The selective extraction of 4-OBSA-, from its mixture with p-TSA-, as well as coextraction of both anions is shown. The results demonstrate the utility of electrochemical modulation for the controlled extraction of ions from an aqueous phase into an organogel electrolyte phase. This offers potential benefits for various analytical processes including sample preparation and cleanup.