Dielectric liquids

Fig. Ill-13. (a) Plots of molecular density versus distance normal to the interface a is molecular diameter. Upper plot a dielectric liquid. Lower plot as calculated for liquid mercury. (From Ref. 122.) (b) Equilibrium density profiles for atoms A and B in a rare-gas-like mixmre for which o,bb/ o,aa = 0.4 and q,ab is given by Eq. III-56. Atoms A and B have the same a (of Eq. m-46) and the same molecular weight of SO g/mol the solution mole fraction is jcb = 0.047. Note the strong adsorption of B at the interface. [Reprinted with permission from D. J. Lee, M. M. Telo de Gama, and K. E. Gubbins, J. Phys. Chem., 89, 1514 (1985) (Ref. 88). Copyright 1985, American Chemical Society.]...

Until the 1970s the chemical used as the impregnating and dielectric medium for capacitor units was PCB (polychlorinated biphenyl) liquid. It was found to be toxic and unsafe for humans as well as contamination of the environment. For this reason, it is no longer used. The latest trend is to use a non-PCB, non-toxic, phenyl xylyl ethane (PXE-oil), which is a synthetic dielectric liquid of extremely low loss for insulation and impregnation of the capacitor elements or to use mixed polypropylene or allpolypropylene (PP) liquids as the dielectric. A non-oil dielectric, such as epoxy resin, is also used. 

Kinetics of Electron-Ion Recombination in Irradiated Dielectric Liquids... 

Allen, A.O.(1976), Drift Mobilities and Conduction Band Energies of Excess Electrons in Dielectric Liquids, NSRDS-NBS 58, National Bureau of Standards, Washington, D.C. 

Chemical reagents are primarily concerned with dielectric liquids or solids. For metal oxides such as ferrites, however, magnetic losses occur in the microwave region. As for a dielectric material, a complex magnetic permeability is defined as given by Eq. (16) ... 

Uses Dielectric liquids in fixed paper capacitors heat-transfer liquid widely used in transformers and utility transmission lines swelling agents for transmission seals ingredient in lubricants, oils, and greases plasticizers for cellulose products, vinyl, and chlorinated rubbers in polyvinyl acetate to improve fiber-tear properties. In fluorescent and high-intensity discharge ballasts manufactured prior to 1979 (U.S. EPA, 1998) and in electric motors (Monsanto, 1960). 

Warman, J.M. de Haas, M.P. Hummel, A. Conduction and Breakdown in Dielectric Liquid Goldschwartz, J.M., Niessen, A.K., Boone, W., Eds. Delft Univ. Press Delft, Netherlands, 1975 70. 

Aprile, E. Curioni, A. Egorov, V. Giboni, K.L. Oberlack, U. Ventura, S. Doke, T. Taki-zawa, K. Chupp, E.L. Dunphy, P.P. Nucl. Instrum. Methods Phys. Res. A 2001,461, 256. Lopes, M.I. Chepel, V. Presented at the 2002 IEEE 14th Internatl. Conf. on Dielectric Liquids, Graz, Austria, 2002. Unpublished. 

In both of the latter cases, the appearance of a triple point, CP, of coexistence is characteristic—in the second case, of two metallic and one dielectric phase, and in the third of a metal and two dielectric (liquid and gaseous) phases. 

In very pure nonpolar dielectric liquids, electron injection currents at very sharp tips follow the Fowler-Nordheim voltage dependence (Halpem and Gomer, 1969), just as is the case in solid insulators, and in a gas, as described before. In a study of the electrochemical behavior of CNT cathodes (Krivenko et al., 2007) direct experimental proof was found of electron emission into the liquid hexamethylphosphortriamide, which was chosen because it is a convenient solvent for the visualization of solvated electrons at room temperature the solution will show an intense blue coloration upon the presence of solvated electrons. Electron spin resonance showed prove of a free electron. Electrogenerated (as opposed to photogenerated) solvated electrons have been used in the synthesis of L-histidinol (Beltra et al., 2005), albeit that in that work the electrons were generated electrochemically from a solution of LiCl in EtNH2, which is a solvent that is easier to handle than liquid ammonia (boiling points at atmospheric pressure are 17 °C and -33.34 °C, respectively). 

Infelta PP, de Haas MP, Warman JM. (1977) The study of the transient conductivity of pulse irradiated dielectric liquids on a nanosecond timescale using microwaves. RadiatPhys Chem 10 353-365. 

I. Adamczewski, Ionization, Conductivity and Breakdown in Dielectric Liquids , Taylor and Francis, London, 1969. 

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