Chemical Composition Of Electrodes Research Articles

Synthesis of Carbon Nanostructures Using Arc Discharge in the Liquid Phase

In this paper the synthesis method for nano- and micro- powders in arc discharge in the liquid phase is considered. The proposed method allows to synthesize nano- and microparticles of different chemical compositions. The synthesis mechanism and the scheme of combination of chemical compositions of electrodes and the liquid medium are described.

Nanostructured Polyphase Catalysts Based on the Solid Component of Welding Aerosol for Ozone Decomposition.

Samples of the solid component of welding aerosols (SCWAs) were obtained as a result of steel welding by ANO-4, TsL‑11, and UONI13/55 electrodes of Ukrainian manufacture. The phase compositions of the samples, both freshly prepared (FP) and modified (M) by water treatment at 60 °C, were studied by X-ray phase analysis and IR spectroscopy. All samples contain magnetite demonstrating its reflex at 2θ ~ 35° characteristic of cubic spinel as well as manganochromite and iron oxides. FP SCWA-TsL and FP SCWA-UONI contain such phases as СaF2, water-soluble fluorides, chromates, and carbonates of alkali metals. After modification of the SCWA samples, water-soluble phases in their composition are undetectable. The size of magnetite nanoparticles varies from 15 to 68 nm depending on the chemical composition of electrodes under study. IR spectral investigations confirm the polyphase composition of the SCWAs. As to IR spectra, the biggest differences are apparent in the regions of deformation vibrations of M–O–H bonds and stretching vibrations of M–O bonds (M–Fe, Cr). The catalytic activity of the SCWAs in the reaction of ozone decomposition decreases in the order SCWA-ANO > SCWA-UONI > SCWA-TsL corresponding to the decrease in the content of catalytically active phases in their compositions.

Effect of the Chemical Composition of Electrode Materials and deposition Parameters on the Properties of Electrospark-Deposited Coatings. I. Mass Transfer Rate and Coating Composition

Cermet coatings based on Ni–Al alloys and titanium–chromium diboride are electrospark-deposited onto 40Kh steel. It is analyzed how the metal-to-refractory phase ratio in the electrode material and the deposition parameters influence the mass-transfer kinetics, thickness, and composition of the coatings. Higher metal content of the electrode material activates mass transfer and increases thickness of the coatings (up to 700 μm). The integrity, roughness, and thickness of the coatings can be controlled by varying electrospark deposition parameters and chemical composition of the electrodes.

Capacitance–voltage characteristics of metal-polymer-silicon device with inkjet-printed Ag electrode

Capacitance–voltage (C–V) behaviors of metal-polymer-silicon capacitors having inkjet-printed silver (Ag) electrodes were characterized. Polymers of polyvinyl alcohol (PVA) and poly-4-vinylphenol (PVP) were spin-coated on heavily doped silicon for dielectric layer, on which Ag ink was directly patterned. The C–V characteristics of inkjet-printed Ag devices were compared with those of evaporated Al devices. Cross-linked PVA device (1000 s UV exposure) with inkjet-printed Ag electrode showed higher capacitance and dielectric constant (366 pF, k = 5.10) than the device with evaporated Al electrode (109 pF, k = 1.57, 1 mm radius). For the PVP dielectric layer, device with inkjet-printed Ag showed lower capacitance and dielectric constant than evaporated Al device. Interface states between the polymer dielectrics and metal electrodes were investigated by scanning electron microscopy. In addition, cross-linking of PVA with UV exposure, confirmed by Fourier transformed infrared spectroscopy, critically influenced the flat band voltage for both inkjet-printed and evaporated electrode's devices. Chemical composition of Ag electrode was analyzed by x-ray photoelectron spectroscopy. In summary, it was found that degree of cross-linking, interface states between polymer and electrode, and chemical composition of electrode could determine electrical performances, respectively.

Spectral distribution of sound waves in an electric discharge

1. It was established that the chemical composition of electrodes affects the acoustic characteristics of an electric discharge. 2. The results obtained make possible certain quantitative estimates of the plasma state of matter.