Free-ion Yield in the Radiolysis of Dimethylsulfoxide

1971 ◽  
Vol 49 (13) ◽  
pp. 2248-2253 ◽  
Author(s):  
T. K. Cooper ◽  
D. C. Walker
Keyword(s):  
Dielectric Constant ◽  
Negative Ions ◽  
Pure Liquid ◽  
Solvated Electrons ◽  
Gaseous Products ◽  
Free Ions ◽  
Competitive Reactions ◽  
Large Dielectric Constant ◽  
Polar Media ◽  
Wide Range

Dimethylsulfoxide is a dipolar aprotic solvent of high basicity having a large dielectric constant (ε = 48) but very low solvating power for negative ions. The radiation yield of "free ions" in this liquid is in accord with the dielectric constant, G(free ions) = 1.8 ± 0.2, but these "free ions" do not resemble the strongly solvated electrons found in other polar media such as water and aliphatic alcohols. Evidence for this conclusion is based principally on competitive reactions involving a wide range of scavengers in competition with nitrous oxide. The radiation yields of gaseous products from pure liquid dimethylsulfoxide are G(H2) = 0.20 ± 0.01, G(CH4) = 3.3 ± 0.1, and G(C2H6) = 0.49 ± 0.03.

Pulse Radiolysis of Formamide and Formamide–Water Mixtures

1971 ◽  
Vol 49 (20) ◽  
pp. 3398-3401 ◽  
Author(s):  
D. C. Walker ◽  
S. C. Wallace
Keyword(s):  
Dielectric Constant ◽  
Absorption Spectrum ◽  
Absorption Band ◽  
Optical Absorption ◽  
Optical Absorption Spectrum ◽  
Pulse Radiolysis ◽  
Water Molecules ◽  
Pure Liquid ◽  
Solvated Electrons ◽  
Hydrated Electrons

From the optical absorption spectrum observed by a sub-nanosecond pulse radiolysis method it is concluded that irradiated pure liquid formamide (dielectric constant = 109) does not yield solvated electrons with lifetimes >10−11 s. In formamide–water mixtures the hydrated electron is formed in low yield and the position of the absorption band of eaq− is not altered by changing the composition. Apparently formamide reacts much more rapidly with thermalized electrons than it does with hydrated electrons. The latter may be formed in formamide–water mixtures due to aggregates of water molecules.

scholarly journals METAL–INSULATOR TRANSITIONS IN TETRAHEDRAL SEMICONDUCTORS UNDER LATTICE CHANGE

2004 ◽  
Vol 18 (07) ◽  
pp. 975-988
Author(s):  
SHAILESH SHUKLA ◽  
DEEPAK KUMAR ◽  
NITYA NATH SHUKLA ◽  
RAJENDRA PRASAD
Keyword(s):  
Dielectric Constant ◽  
Fermi Surface ◽  
Lattice Constant ◽  
Critical Behavior ◽  
Tight Binding ◽  
Metal Insulator ◽  
Wide Range ◽  
Insulating Phase ◽  
Tetrahedral Semiconductors ◽  
Lattice Compression

Although most insulators are expected to undergo insulator to metal transition on lattice compression, tetrahedral semiconductors Si, GaAs and InSb can become metallic on compression as well as by expansion. We focus on the transition by expansion which is rather peculiar; in all cases the direct gap at Γ point closes on expansion and thereafter a zero-gap state persists over a wide range of lattice constant. The solids become metallic at an expansion of 13% to 15% when an electron Fermi surface around L-point and a hole Fermi surface at Γ-point develop. We provide an understanding of this behavior in terms of arguments based on symmetry and simple tight-binding considerations. We also report results on the critical behavior of conductivity in the metal phase and the static dielectric constant in the insulating phase and find common behavior. We consider the possibility of excitonic phases and distortions which might intervene between insulating and metallic phases.

scholarly journals Electroless Deposited Gold Nanoparticles on Glass Plates as Sensors for Measuring the Dielectric Constant of Solutions

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Y. Kobayashi ◽  
Y. Ishii
Keyword(s):  
Dielectric Constant ◽  
Au Nanoparticles ◽  
Glass Plate ◽  
Au Nanoparticle ◽  
Peak Wavelength ◽  
Nanoparticle Deposition ◽  
Metal Plating ◽  
Large Dielectric Constant ◽  
Electroless Metal Plating ◽  
Glass Plates

This work describes a method for the deposition of Au nanoparticles on glass plates (Au-glass). An electroless metal plating technique was extended to the Au nanoparticle deposition. The technique consisted of three steps that took place on the glass plate: (1) adsorption of Sn2+ ions, (2) deposition of metallic Ag nuclei generated by reducing Ag+ ions with Sn2+ ions on the Sn-adsorbed sites, and (3) deposition of Au nanoparticles by reducing Au+ ions on the Ag surface. TEM observation revealed that metallic Au nanoparticles with a size of  nm were formed on the glass surface. A surface plasmon resonance absorption peak was observed, and its peak wavelength redshifted by immersing the Au-glass into a solution with a large dielectric constant. The redshift corresponded qualitatively to the calculation by the Mie theory accompanying the Drude expression, which was based on the change of the dielectric constant of the solution. The obtained results indicated that the Au-glass functioned as a sensor for measuring the dielectric constant of the solution.

Simple furan-based polymers featuring self-healing function enable efficient eco-friendly organic solar cells with high stability

2021 ◽  
Author(s):  
Shangwen Lu ◽  
Shengchun Qu ◽  
Yingying Deng ◽  
Yueyue Gao ◽  
Gentian Yue ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Solar Cells ◽  
Organic Solar Cells ◽  
High Stability ◽  
Hole Mobility ◽  
Side Chains ◽  
Self Healing ◽  
Good Solubility ◽  
Large Dielectric Constant ◽  
Oligoethylene Glycol

Herein, two simple furan-based polymers PFO3 and PFO4 grafting oligoethylene glycol (OEG) side chains are developed. PFO3 and PFO4 feature high hole mobility, large dielectric constant and good solubility. Compared...

Parametric Models of Ultrasonic Piezoelectric Transducers over a Wide Temperature Range

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000266-000272 ◽  
Author(s):  
Steven A. Morris ◽  
Jeremy Townsend
Keyword(s):  
Dielectric Constant ◽  
Temperature Dependence ◽  
Coupling Coefficient ◽  
Thin Disk ◽  
Piezoelectric Transducers ◽  
Parametric Models ◽  
Model Parameters ◽  
Linear Temperature Dependence ◽  
Linear Temperature ◽  
Wide Range

Piezoelectric ultrasonic transducers are used extensively in well logging and logging-while-drilling applications for pulse-echo operation. We present a method of modeling the operation of ultrasonic thin-disk piezoelectric transducers over a wide range of temperatures. The model is based on using Redwood's version of Mason's model of thin-disk transducers. Laboratory measurements in the oven of non-backed transducers in air are used to extract the Mason model parameters as a function of temperature. Derived parameters are frequency-thickness constant, dielectric constant, and thickness mode coupling coefficient. A fourth parameter, bulk density, is measured independently and assumed constant over temperature. Temperature dependence of frequency thickness constant and coupling coefficient are modeled as linear temperature coefficients. Temperature dependence of the dielectric constant must be specified as a table because of the non-linear temperature dependence of that parameter.

scholarly journals Chitosan-ZnO Nanocomposites Assessed by Dielectric, Mechanical, and Piezoelectric Properties

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1991 ◽  
Author(s):  
Evgen Prokhorov ◽  
Gabriel Luna-Bárcenas ◽  
José Martín Yáñez Limón ◽  
Alejandro Gómez Sánchez ◽  
Yuriy Kovalenko
Keyword(s):  
Dielectric Constant ◽  
Flexible Electronics ◽  
Piezoelectric Properties ◽  
Strong Dependence ◽  
Nanocomposite Films ◽  
Strong Interactions ◽  
Zno Nps ◽  
Chitosan Matrix ◽  
Three Phase ◽  
Wide Range

The aim of this work is to structurally characterize chitosan-zinc oxide nanoparticles (CS-ZnO NPs) films in a wide range of NPs concentration (0–20 wt.%). Dielectric, conductivity, mechanical, and piezoelectric properties are assessed by using thermogravimetry, FTIR, XRD, mechanical, and dielectric spectroscopy measurements. These analyses reveal that the dielectric constant, Young’s modulus, and piezoelectric constant (d33) exhibit a strong dependence on nanoparticle concentration such that maximum values of referred properties are obtained at 15 wt.% of ZnO NPs. The piezoelectric coefficient d33 in CS-ZnO nanocomposite films with 15 wt.% of NPs (d33 = 65.9 pC/N) is higher than most of polymer-ZnO nanocomposites because of the synergistic effect of piezoelectricity of NPs, elastic properties of CS, and optimum NPs concentration. A three-phase model is used to include the chitosan matrix, ZnO NPs, and interfacial layer with dielectric constant higher than that of neat chitosan and ZnO. This layer between nanoparticles and matrix is due to strong interactions between chitosan’s side groups with ZnO NPs. The understanding of nanoscale properties of CS-ZnO nanocomposites is important in the development of biocompatible sensors, actuators, nanogenerators for flexible electronics and biomedical applications.

Well dispersed silicon nanospheres synthesized by RF thermal plasma treatment and their high thermal conductivity and dielectric constant in polymer nanocomposites

RSC Advances ◽  
2015 ◽  
Vol 5 (13) ◽  
pp. 9432-9440 ◽  
Author(s):  
Guolin Hou ◽  
Benli Cheng ◽  
Fei Ding ◽  
Mingshui Yao ◽  
Yuebin Cao ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Constant ◽  
Plasma Treatment ◽  
Polymer Nanocomposites ◽  
Thermal Plasma ◽  
High Thermal Conductivity ◽  
Large Dielectric Constant ◽  
Rf Thermal Plasma

Nanocomposites with high thermal conductivity and large dielectric constant incorporated with Si nanospheres prepared by thermal plasma are reported.

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