Search results for "Electrolyte"
showing 10 items of 746 documents
Electrical fluctuations in monolayer-protected metal nanoclusters
2008
Abstract Monolayer-protected clusters (MPCs) are formed by a neutral or charged metallic core surrounded by an organic ligand monolayer. We estimate the electric potential fluctuations of a MPC in an electrolyte solution by using the equilibrium fluctuation–dissipation theorem and the non-linear Poisson–Boltzmann equation extended to account for ion penetration in the monolayer. Significant fluctuations are predicted because the MPC capacitance is small (approximately 1 aF). We study also the non-equilibrium case of a MPC sandwiched between two electrodes and estimate the current noise considering the nanocluster as a single electron transistor and using a theoretical approach based on the …
Photoemission of electrons into electrolyte from cadmium oxide layers formed by anodic oxidation of undeformed and plastically deformed cadmium plates
1995
Studies of electron emission (external photoeffect) at the electrode/solution interface are an important part of contemporary photoelectrochemistry. The results of systematic studies of this phenomenon led to the formulation of fundamental relationships and to new methods for investigation of the physicochemical processes occurring at the electrode-electrolyte interface [1-4]. In particular, photoemission measurements enabled a number of parameters relating to the structure of the semiconductor/electrolyte interface to be determined. The photoemission current from semiconductors with many surface states to solutions with a sufficiently high electrolyte concentration is described by the well…
Memory effects in functionalized conducting polymer films: titanocene derivatized polypyrrole in contact with THF solutions
2003
Abstract Films with a polypyrrole matrix and pendant titanocene dichloride centers, p(Tc3Py), have been obtained by potentiostatic electropolymerization of the titanocene-pyrrolyl derivative, Tc3Py=Tc(CH 2 ) 3 NC 4 H 4 (Tc=Cl 2 TiCpCp′, Cp=C 5 H 5 , Cp′=C 5 H 4 ), in acetonitrile (AN) solutions on a Pt surface. The redox activity has been studied after the transfer of the film-coated electrode into the monomer-free solution of the same electrolyte, TBAPF 6 , in THF. Contrary to the case of AN or dichloromethane solutions, one can achieve a stable redox activity of the immobilized Tc centers in THF solutions during a series of cycles. A parallel between the redox properties of the Tc complex…
Proton conducting polymer composites for electrochromic devices
1999
Abstract This report describes composite proton electrolytes composed of nanosize zirconium phosphate or antimonic acid particles suspended in a poly(vinyl acetate)/glycerin gel matrix. The proton conductivity was 10 −3 –10 −4 S/cm at room temperature, thermal stability prevailed up to at least 110°C, and compatibility was found with oxide electrodes; these properties makes the electrolyte suitable for use in solid state electrochemical devices. The temperature dependence of the conductivity was found to obey the Williams-Landel-Ferry relationship at temperatures over 60°C, thus suggesting that the ion conductivity in the composite electrolyte can be described by mechanisms normally taken t…
Thin Films by Multilayer Build-Up of Electron Transport Materials
2003
We present the synthesis and the electrochemical characterization of polymeric electron transport materials, synthesized by polycondensation of substituted triazines and α,ω-dihaloalkanes. They can be reversibly reduced with the least negative potential at −0.39 V, which is below the reduction potential of oxygen. In addition, the formation of polyelectrolyte multilayers is possible by the electrostatic self-assembly method. This multilayer formation takes place in a very defined way up to thirty double layers. An example of one of the polymeric triazine electron transport materials synthesized and a schematic diagram of a self-assembled multilayer film.
Composite Polymer Electrolytes with Improved Lithium Metal Electrode Interfacial Properties: I. Elechtrochemical Properties of Dry PEO‐LiX Systems
1998
Several types of lithium ion conducting polymer electrolytes have been synthesized by hot-pressing homogeneous mixtures of the components, namely, poly(ethylene oxide) (PEO) as the polymer matrix, lithium trifluoromethane sulfonate (LiCF{sub 3}SO{sub 3}), and lithium tetrafluoroborate (LiBF{sub 4}), respectively, as the lithium salt, and lithium gamma-aluminate {gamma}-LiAlO{sub 2}, as a ceramic filler. This preparation procedure avoids any step including liquids so that plasticizer-free, composite polymer electrolytes can be obtained. These electrolyte have enhanced electrochemical properties, such as an ionic conductivity of the order of 10{sup {minus}4} S/cm at 80--90 C and an anodic bre…
<title>Proton conducting polymer electrolytes for electrochromic devices</title>
1997
This report concerns a composite proton electrolyte suitable for use in electrochromic devices. The electrolyte consists of nanosize hydrated oxide (aluminum, silicon or antimonic) particles suspended in a poly(vinyl acetate) matrix. All of the water was strongly bonded, thus making the electrolytes less harmful without considerably decreasing the conductivity. The proton conductivity of the electrolyte was approximately 10-4 S/cm at room temperature, practically independent of its amount of absorbed water.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Probing the role of water in protein conformation and function
2004
Life began in a bath of water and has never escaped it. Cellular function has forced the evolution of many mechanisms ensuring that cellular water concentration has never changed significantly. To free oneself of any conceptual distinction among all small molecules, solutes and solvents, means that experiments to probe water's specific role in molecular function can be designed like any classical chemical reaction. Such an ‘osmotic stress’ strategy will be described in general and for an enzyme, hexokinase. Water behaves like a reactant that competes with glucose in binding to hexokinase, and modulates its conformational change and activity. This ‘osmotic stress’ strategy, now applied to ma…
Applicability of Waste Engine Oil for the Direct Production of Electricity
2021
New methods for the use of waste products as input for other technologies are a constant subject of research efforts. One such product is waste engine oil. Due to the constantly increasing number of motor vehicles in the world, the recycling or application of engine oils for energy production purposes is currently of considerable importance. This paper contains research regarding the analysis of the electro-oxidation potential of waste engine oil, and thus the possibility of using such oil as a material in fuel cells. The research demonstrates the basic possibility of the electro-oxidation of this oil emulsion on a platinum electrode in an acid electrolyte (aqueous solution of H2SO4). It wa…
Generalization of a finite-difference numerical method for the steady-state and transient solutions of the nernst—planck flux equations
1985
Abstract A generalization of the numerical method of Brumleve and Buck for the solution of Nernst—Planck equations when convective flux and electric current are involved has been developed. The simulation procedure was applied to a specific case: transport of strong electrolytes in a wide-pore membrane with simultaneous diffusion, convection and electric current. Good agreement was found between experimental data and computed results.