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KNbO 3 and KNb 0.9 M 0.1 O 3-α (M = Ti, Hf, Zr, Sc, In, Yb) were prepared by solid state reaction at 920 °C for 4 h and characterized by X-ray diffraction. The electrical properties of solid electrolytes were measured by AC impedance in wet air, wet Ar and dry Ar. The order of conductivity in different atmospheres is σ (wet air)> σ (wet Ar)> σ (dry Ar). Among KNb 0.9 M 0.1 O 3-α (M = Ti, Hf, Zr, Sc, In, Yb), KNb 0.9 In 0.1 O 3-α displays the highest conductivity. The carriers transport numbers of each material were measured by concentration cell method. The results show KNb 0.9 In 0.1 O 3-α is almost a pure proton conductor below 625 °C. KNb 0.9 In 0.1 O 3-α has excellent chemical stability against CO 2 and H 2 O, but in the process of use should avoid rapid heating and cooling. • KNbO 3 , a new type of proton conductor, was prepared by solid-phase synthesis method. High density solid electrolytes were obtained by sintering at 950°C for 4h. Compared with traditional proton conductor, the sintering temperature is greatly reduced and the sintering time is shortened. • The effects of different doping elements on the electrical properties of KNbO 3 proton conductors were studied for the first time. In this study, we consider that the radius and valence of the doped elements together affect the conductivity of the solid electrolytes. • The tolerance of the material to CO 2 and H 2 O and the thermal cycle stability were tested. The material has excellent chemical stability against CO 2 and H 2 O, but rapid heating and cooling should be avoided in the process of use. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride-hexafluropropylene) (PVDF-HFP) and poly(methyl methacrylate) (PMMA)-based gel polymer electrolytes (GPEs) comprising propylene carbonate and diethyl carbonate mixed plasticizer with variation of lithium perchlorate (LiClO4) salt concentrations have been prepared using a solvent casting technique. Structural characterization has been carried out using XRD wherein diffraction pattern reveals the amorphous nature of sample up to 7.5wt.% salt and complexation of polymers and salt have been studied by FTIR analysis. Surface morphology of the samples has been studied using scanning electron microscope. Electrochemical impedance spectroscopy in the temperature range 303–363K has been carried out for electrical conductivity. The maximum room temperature conductivity of 2.83×10−4S cm−1 has been observed for the GPE incorporating 7.5wt.% LiClO4. The temperature dependence of ionic conductivity obeys the Arrhenius relation. The increase in ionic conductivity with change in temperatures and salt content is observed. Transport number measurement is carried out by Wagner’s DC polarization method. Loss tangent (tan δ) and imaginary part of modulus (M′′) corresponding to dielectric relaxation and conductivity relaxation respectively show faster relaxation process with increasing salt content up to optimum value of 7.5wt.% LiClO4. The modulus (M′′) shows that the conductivity relaxation is of non-Debye type (broader than Debye peak).

A bilayer membrane based on a heterogenous cation exchange membrane with a homogeneous cation exchange layer and a polyaniline on its surface is prepared. The intercalation of polyaniline into the membrane with a homogeneous cation exchange layer is performed by oxidative polymerization of aniline. The influence of the homogeneous cation exchange layer and the polyaniline on the structure, conductivity, diffusion permeability, selectivity, and current-voltage curve of the heterogeneous cation exchange membrane is established. Membrane properties are studied in the HCl, NaCl, and CaCl 2 solutions. The homogeneous cation exchange layer has a negligible effect on the transport properties of the initial heterogeneous membrane. The polyaniline synthesis leads to a decrease in the macropore volume in the membrane structure, conductivity, and diffusion permeability. The counterion transport number in the bilayer membrane is significantly reduced in a solution of calcium chloride and practically does not change in sodium chloride and hydrochloric acid. In addition, the asymmetry of the diffusion permeability and shape of current-voltage curve depending on the orientation of the membrane surface to the flux of electrolyte or counterion are found.

The high ionic conductivity of Na-doped SrSiO3 (SNS) is a topic of interest due to contradictory reports on its conductivity and stability by various groups. From a recent NMR study, it is proposed that Na+ is mainly responsible for ionic conductivity in an amorphous Na2Si2O5 phase present in SNS. The present study further extends to determine experimentally the ion transport number as well as material characteristics after long time annealing at 600 °C. The conductivity behavior of as-sintered and annealed nominally Sr0.6Na0.4SiO3-δ is investigated and a sharp fall (~ 2 order magnitude) of the same at 800 °C is found. An XPS study is included for comprehensive understanding of conductivity and degradation behavior of SNS material. On basis of the collective results, we propose a rational description of the conduction and material degradation of SNS. [ABSTRACT FROM AUTHOR]

The high ionic conductivity of Na-doped SrSiO3 (SNS) is a topic of interest due to contradictory reports on its conductivity and stability by various groups. From a recent NMR study, it is proposed that Na+ is mainly responsible for ionic conductivity in an amorphous Na2Si2O5 phase present in SNS. The present study further extends to determine experimentally the ion transport number as well as material characteristics after long time annealing at 600 °C. The conductivity behavior of as-sintered and annealed nominally Sr0.6Na0.4SiO3-δ is investigated and a sharp fall (~ 2 order magnitude) of the same at 800 °C is found. An XPS study is included for comprehensive understanding of conductivity and degradation behavior of SNS material. On basis of the collective results, we propose a rational description of the conduction and material degradation of SNS. [ABSTRACT FROM AUTHOR]

Chitosan has been successfully incorporated as a filler in a polyethylene oxide (PEO) and lithium trifluoromethanesulfonate (LiCF3SO3) matrix with a combination of plasticizers, namely 1,3-dioxolane (DIOX) and tetraethylene glycol dimethylether (TEGDME). The composite gel-polymer electrolyte (CGPE) membranes were prepared by solution casting technique in an argon atmosphere. The prepared membranes were subjected to SEM, TG/DTA and FT-IR analyses. A Li/CGPE/Li symmetric cell was assembled and the variation of interfacial resistance was measured as a function of time. The lithium transference number (Li+t) was measured and the value was calculated as 0.6 which is sufficient for battery applications. The electrochemical stability window of the sample was studied by linear sweep voltammetry and the polymer electrolyte was found to be stable up to 5.2 V. [ABSTRACT FROM AUTHOR]

Composite gel polymer electrolytes (CGPE) were prepared using 1,3 Dioxolane (DIOX)/Tetraethyleneglycol dimethylether (TEGDME) as a combination of plasticizers, comprising with PEO, lithium salt (LiClO4) with the addition of filler SiO2. The composite gel polymer electrolytes were prepared by simple solution casting technique in an argon atmosphere. The electrolyte films were subjected to thermal, structural, morphological and electrochemical ac impedance analysis. A Lithium symmetric cell (Li/CGPE/Li) was fabricated and interfacial resistance as a function of time was studied. The film was thermally stable up to 298 °C. The ionic conductivity of high conducting sample is obtained in the order of 10−4 at ambient temperature. The transport properties of the gel polymer electrolyte were measured and the values are 0.6 which is sufficient for battery applications. The stability of the electrolyte film was analysed using the linear sweep voltammetry technique and the film was stable up to 3.4 V. [ABSTRACT FROM AUTHOR]

Composite gel polymer electrolytes (CGPE) were prepared using 1,3 Dioxolane (DIOX)/Tetraethyleneglycol dimethylether (TEGDME) as a combination of plasticizers, comprising with PEO, lithium salt (LiClO4) with the addition of filler SiO2. The composite gel polymer electrolytes were prepared by simple solution casting technique in an argon atmosphere. The electrolyte films were subjected to thermal, structural, morphological and electrochemical ac impedance analysis. A Lithium symmetric cell (Li/CGPE/Li) was fabricated and interfacial resistance as a function of time was studied. The film was thermally stable up to 298 °C. The ionic conductivity of high conducting sample is obtained in the order of 10−4 at ambient temperature. The transport properties of the gel polymer electrolyte were measured and the values are 0.6 which is sufficient for battery applications. The stability of the electrolyte film was analysed using the linear sweep voltammetry technique and the film was stable up to 3.4 V. [ABSTRACT FROM AUTHOR]

Composite gel polymer electrolytes (CGPE) were prepared using 1,3 Dioxolane (DIOX)/Tetraethyleneglycol dimethylether (TEGDME) as a combination of plasticizers, comprising with PEO, lithium salt (LiClO4) with the addition of filler SiO2. The composite gel polymer electrolytes were prepared by simple solution casting technique in an argon atmosphere. The electrolyte films were subjected to thermal, structural, morphological and electrochemical ac impedance analysis. A Lithium symmetric cell (Li/CGPE/Li) was fabricated and interfacial resistance as a function of time was studied. The film was thermally stable up to 298 °C. The ionic conductivity of high conducting sample is obtained in the order of 10−4 at ambient temperature. The transport properties of the gel polymer electrolyte were measured and the values are 0.6 which is sufficient for battery applications. The stability of the electrolyte film was analysed using the linear sweep voltammetry technique and the film was stable up to 3.4 V. [ABSTRACT FROM AUTHOR]

Electrodialytic (ED) transport of carboxylic acids from their ternary mixtures (acetic, malic and citric) of different compositions were investigated through anion exchange membrane (AEM). Solution pH played crucial role in selectivity and ion transport (expressed by limiting current density, LCD). These observations were analysed based on flow hydrodynamics, ion specific properties and ionic interaction with AEM influencing water uptake and membrane resistance. Fractional hydrolysis of weak acids generated complex mixture of multiple anions of varying charges which strongly influenced LCD. Theoretically estimated LCD (from effective diffusivity, D eff and Sh number based effective mass transfer coefficient, k eff ) could closely match experimental LCD (±4–8% deviation). The nature of solute species, concentration and their interaction with AEM strongly influenced ion transport. Estimation of D eff , transport number, ion exchange equilibrium and membrane resistance could satisfactorily explain the observed LCD. At low pH, LCD was proportional to available free ions while, at pH > 5.2 component specific properties/interactions dominated. Water uptake indicated variation in micro-structure and ion selectivity with different compositions of ternary mixture. This was attributed to shrinkage/swelling of membrane due to ion-membrane interactions. Stronger hydrophobic interaction of acetic acid caused shrinkage of micro-structure resulted in low water uptake but got reversed at higher pH. [ABSTRACT FROM AUTHOR]

Polyvinyl chloride (PVC)-supported stannous phosphate (SP) is a newly synthesized composite material used to make porous, mechanically, and thermally stable composite membrane. Such composite membranes have been prepared by the mixing of organic and inorganic materials, and it shows a lot of applications in the field of purification and filtration technologies. The composite material and designed membrane have been characterized and identified on the basis of their chemical composition, ion exchange capacity, x-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TGA) plus differential thermal (DTA) analysis, and scanning electron microscopy (SEM). The characterizations and analysis demonstrated the functional groups, material nature, thermal stability, surface structure, porosity, elemental percentages, ion transportation, etc. Teorell Meyer and Seviers (TMS) theoretical approach is used to obtain the various important electrochemical parameters of membrane-like charge density, transport number, mobility ratio, charge effectiveness, etc. [ABSTRACT FROM AUTHOR]

Three distinct operational conditions, namely, ohmic, limiting current, and electroconvection region, respectively, can be created by applying different electric fields during ED operations. The fundamental of cation transport under ohmic and limiting current is well understood, however, the mechanism on cation transport under electroconvection is unclear. In order to clarify the feasibility of operating ED under electroconvection for the treatment of industrial wastewater (copper ion as the target pollutant), the methods of current-voltage profiling (C-V curve) and electrochemical impedance spectroscopy (EIS) were used to study the transport characteristics of Cu2+ through a cationic exchange membrane (CEM). The relevant operational parameters obtained above under electroconvection conditions were applied to a continuous ED system as to investigate the removal efficiency of Cu2+ -containing wastewater. Results indicated that ED system operated under electroconvection conditions was able to achieve high Cu2+ removal efficiency (around 74% in 4-min treatment) at high electricity efficiency as the theoretical calculation (based on Cu2+ transport number close to 1.0). The pH of copper wastewater in the ED system decreased slightly from 4.7 to 4.0 under electroconvection operation. The interface at the membrane-water was perturbed by the electroconvection operation, which facilitated ions transport across the membrane. An equivalent circuit composed of the Rs, Cm and Rm (parallel circuit representing the CEM), and constant phase element described well the Cu2+ transport behavior in the membrane-solution system according to the p value is greater than 1.0. [ABSTRACT FROM AUTHOR]

Herein, we report the galvanostatic modification of a commercial cation exchange membrane CMX by polypyrrole (Ppy). The presence of Ppy in the cation exchange membrane (CEM) was confirmed by cyclic voltammetry, stereo microscopy, fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray. Ppy was present both on the membrane surface and inside the pores. The quantity of Ppy in CEM, compactness of Ppy, and the charges on Ppy (negative or positive) were controlled effectively by changing the electrosynthesis conditions. The permeability and water content of the modified membranes obtained under different conditions were investigated. The transport properties of the modified CEMs were evaluated qualitatively using polarization curves and quantitatively by chronopotentiometry. NaCl and MgCl 2 solutions ranging in concentrations from 5 mM to 0.1 M were used for testing the selectivity. The presence of Ppy in the membranes decreased the transport number of Na and Mg, and the reduction in transport number was more significant for Mg. [ABSTRACT FROM AUTHOR]

Homogeneous cation-exchange membranes were prepared through evaporation and phase inversion methods using sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) (SPPO) and sulfonated polyvinylchloride as binders. The effect of polymers blend's ratio and preparation method on structure and electrochemical properties of the prepared membranes were evaluated. The microstructures of the membranes were investigated by scanning electron microscopy (SEM) and the sulfonation of polyvinylchloride was confirmed by elemental analyses. Moreover, the membranes performance was evaluated by ion-exchange capacity (IEC), fixed ion concentration, membrane potential, transport number, permselectivity, areal resistance, ionic permeability, flux of ions, current efficiency, membrane oxidative stability, mechanical properties and water content tests. The results indicated that IEC and water content were affected by the SPPO content and microstructures of the membranes. The results showed increased efficiency and suitable electrochemical properties for membranes prepared by the evaporation method in comparison with others. Also, $$\hbox {Fe}_{2}\hbox {O}_{3}$$ nanoparticles were synthesized at room temperature by a simple sonochemical reaction between ferric chloride and NaOH. The results revealed that the addition of different amounts of $$\hbox {Fe}_{2}\hbox {O}_{3}$$ nanoparticles to the polymeric matrix could affect the hydrophilicity and transport properties of ion-exchange membranes. [ABSTRACT FROM AUTHOR]

Electrical transport in orthorhombic ytterbium and lutetium tungstates with Sc(WO) structural type was studied. It was proved by using two independent methods (EMF, dependence of conductivity on pressure of oxygen in the gas phase) that these phases are purely ionic conductors. It was found by Tubandt method for Lu(WO) the negligible contribution of the [WO] anion into transport, which, together with the results of the EMF technique, indicates a predominantly oxygen character of conductivity. [ABSTRACT FROM AUTHOR]

Novel cation-exchange nanocomposite membranes was fabricated by in-situ formation of zinc oxide nanoparticles in a blend containing sulfonated polyvinylchloride and sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) by a simple chemical method. Also, some nanocomposite samples were prepared by incorporation of previously synthesized ZnO nanoparticles into the casting solution (ex-situ method). The prepared nanocomposite samples and nanoparticles were characterized by several techniques including water contact angle measurements, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. The water contact angle measurements confirmed the increased hydrophilicity of the nanocomposite membranes. The SEM surface microphotographs indicated that ZnO nanoparticles were uniformly dispersed throughout the polymeric matrix. The influence of additive concentration on electrochemical and physicochemical properties of prepared ion-exchange nanocomposite membranes was studied. Various investigations revealed that the in-situ preparation of ZnO nanoparticles in the membrane structure had a considerable effect on the membrane efficiency and could improve the transport properties. [ABSTRACT FROM AUTHOR]

In this work, the plastic crystal polymer electrolytes (PCPEs), composed of polyacrylonitrile (PAN), succinonitrile (SN) and lithium bis(trifluoromethane)sulfonimide (LiTFSI) were prepared. The concentrations of lithium salt were varied by weight percentage from 10 wt% to 50 wt%. The ionic conductivity of the PCPE films increases with the increase of lithium salt, where the highest value recorded is in the order of ~10 S cm. The temperature-dependence conductivity analysis shows that the PCPE films exhibit Arrhenius behaviour when subjected to the temperature range from 303 K to 343 K. The decrease in crystallinity was confirmed by X-ray diffraction (XRD) and Differential Scanning Calorimetry (DSC) analyses. The cationic transport number also increases with the increase of salt which corresponds well to their conductivity values. It is found that the films are electrochemically stable up to ~3.6 V as revealed by the linear sweep voltammetry (LSV) analysis. The cyclic voltammetry (CV) plots of the films shown no substantial change in the redox peaks which mean that the charge transfer reaction is reversible. [ABSTRACT FROM AUTHOR]

Mixed ionic and electronic conductivity of three solid charge transfer (CT) complexes of pyridine, 4-methylpyridine (γ-picoline) and 3,5-dimethylpyridine (3,5-lutidine) with ICl (iodine monochloride) are reported. Electrical parameters of the prepared complexes in the pellet form are evaluated at various temperatures and at wide frequency range by employing AC complex impedance spectroscopic technique. Suitable equivalent circuits for the Nyquist plots, which provide the most realistic model of the electrical properties of the CT complexes, have been suggested. Both transport number measurements and impedance spectra reveal that the conduction in γ-picoline-ICl complex is mainly due to ions, in 3,5-dimethylpyridine-ICl complex, it is due to both ions and electrons and in pyridine-ICl complex, it is predominantly due to electrons. The a.c. conductivity measurements of the CT complexes have been carried out in the frequency range of 10-10 Hz within the temperature range of 303-353 K. The variation of a.c. conductivity with frequency follows the Jonscher's universal power law. The temperature dependence of electrical conductivity suggests the semiconducting behaviour of the materials. [ABSTRACT FROM AUTHOR]

The paper deals with relationships between the individual transmembrane fluxes of binary electrolyte solution components and the experimentally measurable quantities describing rates of transfer processes, namely, the electric current, the transmembrane volume flow and the rates of concentration changes in the solutions adjacent to the membrane. Also, we collected and rigorously defined the kinetic coefficients describing the membrane selective and electrokinetic properties. A set of useful relationships between these coefficients is derived. An important specificity of the proposed analysis is that it does not use the Irreversible Thermodynamic approach by analyzing no thermodynamic forces that generate the fluxes under consideration. Instead, all the regularities are derived on the basis of conservation and linearity reasons. The terminology "Kinematics of Fluxes" is proposed for such an analysis on the basis of the analogy with Mechanics where Kinematics deals with regularities of motion by considering no mechanic forces. The only thermodynamic steps of the analysis relate to the discussion on the partial molar volumes of electrolyte and ions that are the equilibrium thermodynamic parameters of the adjacent solutions. These parameters are important for interrelating the transmembrane fluxes of the solution components and the transmembrane volume flow. The paper contains short literature reviews concerned with the partial molar volumes of electrolyte and ions: the methods of measurement, the obtained results and their theoretical interpretations. It is concluded from the reviews that the classical theories should be corrected to make them applicable for sufficiently concentrated solutions, 1 M or higher. The proposed correction is taken into account in the kinematic analysis. [Display omitted] • Membrane phenomena are addressed in terms of transmembrane fluxes. • Contribution of ions to the transmembrane volume flow is analyzed. • The impact of electrostriction on the transmembrane volume flow is discussed. • Kinetic coefficients describing membrane selective properties are collected. • Fundamental relationships between these kinetic coefficients are derived. [ABSTRACT FROM AUTHOR]

A new form of nanocomposite zirconium phosphoborate (ZrPB) ion exchanger incorporating multi-walled carbon nanotubes (CNTs) has been fabricated and studied. Commercial purity CNTs were used as dopant in ZrPB matrix. The topography and morphology of the composite has been explored with the help of scanning electron microscopy and transmission electron microscopy. The microscopy results confirm the spherical nature and 2–5 nm size of ZrPB particles. CNTs are well reinforced evenly in ZrPB matrix. Multifunctionality of the nanocomposite ion exchange material has been studied for electrochemical characteristics as well as for photocatalytic degradation of methylene blue dye. [ABSTRACT FROM AUTHOR]

Solid polymer electrolyte system, polyethylene oxide (PEO) complexed with potassium bicarbonate (KHCO3) salt was prepared by solution-cast technique. Several experimental techniques such as infrared radiation (IR), differential scanning calorimeter (DSC), and composition dependence conductivity, temperature dependence conductivity in the temperature range of 308–368 K and transport number measurements were employed to characterize this polymer electrolyte system. The conductivity of the (PEO+KHCO3) electrolyte was found to be about 3 times larger than that of pure PEO at room temperature. The transference data indicated that the charge transport in these polymer electrolyte systems is predominantly due to K+ ions. Using this polymer electrolyte an electrochemical cell with configuration K+/(PEO+KHCO3)/(I2+C+electrolyte) was fabricated and its discharge characteristics are studied. A number of other cell parameters associated with the cell were evaluated and are reported in this paper.

A combination of impedance spectroscopy and a modified electromotive force method (emf) were used to evaluate the ionic transport numbers and the overall conductivity of several doped lanthanum gallate materials, i.e. La0.9Sr0.1Ga1-xMgxO3-δ (x=0.05-0.30), La0.9A0.1Ga0.8Mg0.2O3-δ (A=Sr, Ba and Ca) and La0.9Sr0.1Ga0.8Mg0.2-yCoyO3-δ (y=0.015 and 0.045). La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM) sample showed the maximum ionic transport number in the temperature range 900-1173 K, around 0.99 in both O2/air and H2/air gradients.La conductividad total y los números de transporte iónico de las composiciones, basadas en el galato de lantano, La0,9Sr0,1Ga1-xMgxO3-δ (x=0,05-0,30), La0,9A0,1Ga0,8Mg0,2O3-δ (A=Sr, Ba, Ca) y La0,9Sr0,1Ga0,8Mg0,2-yCoyO3-δ (y=0.015; 0,045) fueron estudiadas mediante una combinación de técnicas de espectroscopia de impedancia compleja y fuerza electromotriz (fem). La composición La0,9Sr0,1Ga0,8Mg0,2O2,85 (LSGM) presenta el mayor número de transporte iónico, concretamente 0,99 en el rango de temperaturas 900-1173 K, tanto en gradiente de O2/aire como de H2/aire.

[Display omitted] • A simple analytical method was developed to determine D , t + , and Λ. • A proposed model reproduced the time course of the measured current. • D and t + determined by this method showed the same trend as the reported values. • Λ calculated using D and t + showed the same trend as the measured impedance values. • It is important to exclude non-Faradaic processes for accurate analysis. A simple method for simultaneously determining the effective diffusion coefficient of salt (D), transport number (t +), and molar conductivity (Λ) of binary liquid electrolytes using chronoamperometry in a symmetrical parallel-plate lithium cell is proposed. The curve was fitted assuming a mass-transport-limited process to avoid the effect of the nonfaradaic current in chronoamperometry. The fitting function was based on the diffusion model. The D , t + , and Λ values obtained over a wide concentration range (0.005–1.0 M lithium perchlorate in propylene carbonate) show the same trend as those reported in the literature. Furthermore, the molar conductivity of the electrolyte determined using the proposed method also shows the same trend as that measured using the AC impedance method. [ABSTRACT FROM AUTHOR]

• Electrical conductivity of binary solutions of [SBP][BF 4 ], [TEA][OTf] and [TEA][BF 4 ] salts in acetonitrile. • Arrhenius and Vogel-Fulcher-Tammann activation energies of conductivity. • Densities and isobaric thermal expansion coefficients at 293.15 – 348.15 K. • NMR diffusion coefficients, transport numbers and dissociation degree of cations and anions. • Phase transitions, melting temperatures, cold crystallization of pure salts and their binary solutions. The electrical conductivity of binary solutions of tetraethylammonium trifluoromethanesulfonate ([TEA][OTf]), tetraethylammonium tetrafluoroborate ([TEA][BF 4 ]) and spiro-(1,1′)-bipyrrolidinium tetrafluoroborate ([SBP][BF 4 ]) in acetonitrile was measured at atmospheric pressure in the temperature range of 293.15–348.15 K for different salt mole fractions. The highest electrical conductivities of the acetonitrile solutions of [TEA][BF 4 ], [SBP][BF 4 ] and [TEA][OTf] were 96 ± 7, 94.5 ± 0.5 and 71.6 ± 0.5 mS·cm−1, respectively, at 348.15 K. The activation energy of the conductivity for nonassociating electrolytes was calculated using the Arrhenius equation, and the activation energy of the ionic conductivity of glass-forming liquids was calculated using the Vogel-Fulcher-Tamman equation. The cation and anion diffusion coefficients in the [TEA][OTf], [TEA][BF 4 ] and [SBP][BF 4 ] solutions in acetonitrile were determined by the robust pulsed-gradient stimulated echo sequence technique. Experimental density data were used to calculate the isobaric thermal expansion coefficients in the temperature range of 293.15–348.15 K. The thermophysical properties (the temperatures and heats of the phase transitions and the melting temperatures) of the pure salts and their binary solutions in acetonitrile were determined by differential scanning calorimetry. [ABSTRACT FROM AUTHOR]

In this work non-ionic Poly(Oleylmethacrylate), co-polymeric gels of Oleylmethacrylate with styrene and ionic Oleylmethacrylate/Au nanocomposites are synthesized by thermal polymerization techniques and their electrical properties are studied. All these gels are characterized by Fourier Transform-Infrared Spectroscopy, Thermogravimetric analysis, Scanning Electron Microscopy techniques and X-Ray Diffraction study. Complete electrical study of the compounds including impedance and dielectric measurement, ac conductivity, current-voltage and transport number measurement is carried out which show significant results. The ac conductivity values at 35°C for Poly(Oleylmethacrylate) is found to be 9.76 x 10-8 Scm-1 and that of the copolymers are also in the same range. However, the conductivity of the Au nanocomposites in the ratios 1:0.0117 M, 1:0.0233 M and 1:0.0397 M increases considerably to 4.35 x 10-6, 3.17 x 10-5 and 1.05 x 10-4 Scm-1 respectively. Ionic transport number measurement shows that while Poly(Oleylmethacrylate) and the co-polymers do not have any ionic contribution, Poly(Oleylmethacrylate)/Au nanocomposites have up to 45% ionic conduction. A possible mechanism showing electron transfer in the Au nanocomposites is also discussed. [ABSTRACT FROM AUTHOR]

In this work, a systematic work was performed to investigate the electrochemical transport properties of acceptor-doped BaZrO 3 by measuring electromotive force on various gas concentration cells. For the measurements in the wet oxidizing atmosphere, where significant hole conduction occurs, the transport numbers of the ionic conduction were corrected by taking the effect of electrode polarization into consideration. The results revealed that regardless of whether Sc, Y, In, Ho, Er, Tm or Yb was doped, proton conduction predominated in the reducing atmosphere with the transport number close to unit. However, the contribution of ionic conduction weakens, and the contribution of hole conduction enhances, when the samples are exposed to the moist oxidizing atmosphere. In addition, introducing Ba-deficiency results in degraded electrochemical conductivity, but the transport number in either the moist reducing or the moist oxidizing atmosphere does not change obviously. [ABSTRACT FROM AUTHOR]

The chemical stability of PVC-based Neodymium phosphate (NP) ion-exchange membrane shows better results with strong oxidizing agent KMnO4as compared to the acidic and alkaline medium and it was synthesized by sol–gel and die casting method. The characterization of the ion-exchange composite membrane was carried out by employing Fourier transform infrared spectroscopy, thermogravimetry analysis and scanning electron microscopy. The membrane with 25% PVC and 75% NP shows excellent mechanical and thermal stability as well as good ion-exchange capacity. The observed membrane potential data were used to determine the transport number of cation and anion and other electrochemical parameters of the composite membrane. The prepared membrane can be considered as an excellent material for desalination and wastewater treatment applications. [ABSTRACT FROM AUTHOR]