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Circuit Potential (circuit + potential)

Distribution by Scientific Domains
Polymers and Materials Science60%

Kinds of Circuit Potential

  • open circuit potential
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    Selected Abstracts

    Influence of microstructural changes on corrosion behaviour of thermally aged Ti-6Al-7Nb alloy

    MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 5 2004
    L. Thair
    Abstract Solution treatment and ageing (STA) is an effective strengthening method for , + , titanium alloys. This paper reports the effect of solution treatment and aging on the corrosion behaviour of Ti-6Al-7Nb alloy in a simulated body fluid (Ringer's solution). Ti-6Al-7Nb alloy is hot rolled in the , + , field and subjected to solution treatment above and below its beta transus temperature (1283 K). The solution treated specimens are water quenched (WQ), air-cooled (AC), and furnace cooled (FC) at three different rates, and subsequently aged at 823 K for 4 h. Microstructural changes were examined using optical microscopy and phases developed were analyzed using XRD. The influence of microstructure on the corrosion performance of the alloys are discussed in detail based on the Open Circuit Potential (OCP), passive current density and area of repassivation loop values obtained from the cyclic polarization study in Ringer's solution. The passive current density was low (0.5 ,A/cm2) for the specimen with duplex microstructure obtained for specimen solution treated at 1223 K, air-cooled, and aged, in comparison with that for as-rolled specimen (1.5 ,A/cm2). The corrosion aspects resulting from various heat treatments are discussed in detail. [source]

    Donor,Acceptor C60 -Containing Polyferrocenylsilanes: Synthesis, Characterization, and Applications in Photodiode Devices,

    ADVANCED FUNCTIONAL MATERIALS, Issue 3 2008
    Masato Nanjo
    Abstract A series of polyferrocenylsilane (PFS) random copolymers containing covalently bound pendant [C60]fullerene groups, the first well-characterized metallopolymers with pendant C60 units, have been prepared and characterized. The fullerene content of the prepared copolymers ranges from 7 to 24% relative to monomer unit. The desired copolymers were synthesized in three steps: metal-catalyzed ring opening polymerization of sila[1]ferrocenophanes was performed to synthesize random copolymers of poly(ferrocenylmethylphenylsilane -co- ferrocenylchloromethylsilane); the resulting random PFSs were then functionalized by reaction with 11-azido-1-undecanol to give PFSs with pendant azide groups; the desired donor,acceptor C60 -containing PFSs were then synthesized by the reaction of the azide group in the side chains with C60 in toluene at 110,°C. The resulting C60 -containing PFSs are air-stable and soluble in aromatic solvents, chloroform, or THF. The UV-vis spectra of these materials show broad absorption up to 800 nm. Thin films of these materials were examined as the active layer in rare examples of all solid-state sandwich-type diode devices based on ferrocene-fullerene dyads. The devices exhibit photoconducting and photovoltaic responses, with an open circuit potential of ca. 0.3 V under white light illumination. [source]

    Effect of potential on the corrosion behavior of a new titanium alloy for dental implant applications in fluoride media

    MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 2 2004
    A. M. Al-Mayouf
    Abstract The effect of fluoride ion concentration and pH on the corrosion behavior of TCA (60 Ti 10 Ag 30 Cu), which is a new Ti alloy with low melting point, pure Titanium (Ti), and TAV (TiAl6V4) was examined using open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) at different potentials. Results show that the corrosion resistance of TCA and Ti decrease at anodic potentials compared with results obtained at OCP. At one potential the corrosion resistance decrease depends on NaF concentration and pH. TAV shows less resistance against corrosion in fluoride containing saliva. TCA has potentials more positive than Ti and TAV due to surface enrichment of Cu and Ag as Ti dissolves which accelerates the cathodic reaction. Fluoride ion may not hinder the growth of oxide layers on the surfaces of the electrodes. It will have influence on the properties of the oxide layer causing them to be not protective against corrosion in acid media containing fluoride ions. [source]

    Study of the Electroless Silver Seed Formation on Silicon Surface

    CHINESE JOURNAL OF CHEMISTRY, Issue 2 2007
    Hao Tong
    Abstract The silver seed on silicon was prepared through aqueous HF and AgNO3 solution at room temperature. In order to explore the formation process of silver seed on silicon, the methods of open circuit potential with time (OCP- t), anodic stripping sweep voltammetry (ASV) and scanning tunneling microscope (STM) were used in this work. The procedure of silver nucleus growing into large particles was explained by electro-negativity. The growth mechanism of silver seed on silicon has been presented: at first, the silver monolayer and multilayer firstly grows onto silicon without fully covering the surface at the expense of silicon etching due to the silver seed attracting the electron from silicon, after that, the monolayer coalesces together, forming continuous grain film with some silver atoms diffusing into the silicon and the multilayer still grows thick simultaneously. [source]

    Corrosion of some selected ceramic alloys used in fixed partial dentures and their postsolder joints in a synthetic neutral saliva

    EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2009
    Pascal De March
    The electrochemical behavior of several alloys used in the frameworks of fixed partial dentures and their corresponding postsolders was studied in artificial saliva as a function of chemical composition. Open circuit potentials and polarization resistances were measured. The general electrochemical behaviors between the cathodic domain and the oxidation of solvent were characterized using cyclic polarization. The possible galvanic corrosion of coupled parent and postsolder alloys was also studied. The polarization resistances were high or very high. During immersion, the noblest alloys stayed in the immunity domains of their base elements, whereas Ni,Cr alloys were quickly passivated. The oxidation of the noble elements occurred only when the alloys were exposed to very high potentials solely achievable by artificial means. However, problems of galvanic corrosion may occur between an alloy and its postsolder joint if they are both exposed to saliva. Such corrosion may lead to a weakening of the framework. The parent alloy was often potentially affected by such corrosion but with low exchange currents. [source]