Temperature dependence of polarizability of diatomic homonuclear molecules

Buldakov, Mikhail A.; Matrosov, I. I.; Cherepanov, Victor N.

doi:10.1134/bf03355985

Cited by 20 publications

(21 citation statements)

References 16 publications

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“…At −150 °C and high frequency (e.g., 1 MHz), we consider that the dielectric contribution to permittivity only originates from electronic and vibrational polarizations, and ε r,–150 °C (1 MHz) = 5.0. Assuming the electronic and vibrational polarizations are nearly independent of temperature, , the P dip,exp values at 100 MV/m for PMSEMA at −50 and 50 °C (1 Hz) are calculated to be 3.72 and 6.64 mC/m 2 , respectively. Considering that the ratio of P dip,exp / P dip,theory may represent the percentage of dipole flipping, the ratios are 39% and 37% at −50 and 50 °C, respectively.…”

Section: Resultsmentioning

confidence: 99%

Achieving High Dielectric Constant and Low Loss Property in a Dipolar Glass Polymer Containing Strongly Dipolar and Small-Sized Sulfone Groups

Wei

Zhang

Tseng

et al. 2015

ACS Appl. Mater. Interfaces

160

184

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In this report, a dipolar glass polymer, poly(2-(methylsulfonyl)ethyl methacrylate) (PMSEMA), was synthesized by free radical polymerization of the corresponding methacrylate monomer. Due to the large dipole moment (4.25 D) and small size of the side-chain sulfone groups, PMSEMA exhibited a strong γ transition at a temperature as low as -110 °C at 1 Hz, about 220 °C below its glass transition temperature around 109 °C. Because of this strong γ dipole relaxation, the glassy PMSEMA sample exhibited a high dielectric constant of 11.4 and a low dissipation factor (tan δ) of 0.02 at 25 °C and 1 Hz. From an electric displacement-electric field (D-E) loop study, PMSEMA demonstrated a high discharge energy density of 4.54 J/cm(3) at 283 MV/m, nearly 3 times that of an analogue polymer, poly(methyl methacrylate) (PMMA). However, the hysteresis loss was only 1/3-1/2 of that for PMMA. This study suggests that dipolar glass polymers with large dipole moments and small-sized dipolar side groups are promising candidates for high energy density and low loss dielectric applications.

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Section: Resultsmentioning

confidence: 99%

Achieving High Dielectric Constant and Low Loss Property in a Dipolar Glass Polymer Containing Strongly Dipolar and Small-Sized Sulfone Groups

Wei

Zhang

Tseng

et al. 2015

ACS Appl. Mater. Interfaces

160

184

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“…36 and estimated a dependence of 82 × 10 −7 (cm 3 /mol)/K. The dependence has been calculated for optical frequency as 48(1) × 10 −7 (cm 3 /mol)/K by Buldakov et al 62 and for the static limit as 51 × 10 −7 (cm 3 /mol)/K by Sharipov et al 63 We plot literature measurements of nitrogen polarizability in Fig. 5 across a 30 K range.…”

Section: Resultsmentioning

confidence: 96%

Measured relationship between thermodynamic pressure and refractivity for six candidate gases in laser barometry

Egan

Stone

Scherschligt

et al. 2019

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Laser refractometers are approaching accuracy levels where gas pressures in the range 1 Pa < p < 1 MPa inferred by measurements of gas refractivity at a known temperature will be competitive with the best existing pressure standards and sensors. Here, the authors develop the relationship between pressure and refractivity p=c1⋅(n−1)+c2⋅(n−1)2+c3⋅(n−1)3+⋯, via measurement at T = 293.1529(13) K and λ = 632.9908(2) nm for p ≤ 500 kPa. The authors give values of the coefficients c1, c2, c3 for six gases: Ne, Ar, Xe, N2, CO2, and N2O. For each gas, the resulting molar polarizability AR≡2RT3c1 has a standard uncertainty within 16 × 10−6·AR. In these experiments, pressure was realized via measurements of helium refractivity at a known temperature: for He, the relationship between pressure and refractivity is known through calculation much more accurately than it can presently be measured. This feature allowed them to calibrate a pressure transducer in situ with helium and subsequently use the transducer to accurately gage the relationship between pressure and refractivity on an isotherm for other gases of interest.

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“…Similar equations were derived from the Lorentz–Lorenz equation assuming constant R m . − However, there are discrepancies between α P and κ T calculated according to their thermodynamic definition and the respective values from the One-Third rule, demonstrating that treating R m as a constant is not appropriate for accurate α P and κ T evaluations. In addition, the polarizability, which is directly related to R m , was observed to be temperature dependent with a low increasing rate of 1%/1000 K for diatomic molecules, where this effect can be explained by the occupation of higher rotational and vibrational levels − at higher temperatures. A more rigorous approach to calculate α P and κ T is proposed based on the Lorentz–Lorenz equation but without assuming a constant R m .…”

Section: Mathematical Expressions For α P and κ Tmentioning

confidence: 96%

Determination of Volumetric Properties Using Refractive Index Measurements for Nonpolar Hydrocarbons and Crude Oils

Wang

Evangelista

Threatt

et al. 2017

Ind. Eng. Chem. Res.

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A novel method to evaluate volumetric properties, namely the thermal expansivity (α P ) and the isothermal compressibility (κ T ) for nonpolar hydrocarbon systems using refractive index measurements, is presented in this work. New expressions for α P and κ T are derived from the Lorentz–Lorenz equation and the One-Third rule, respectively. A further simplified expression for α P is proposed requiring only refractive index data and molecular weight for calculation. Densities and refractive indices of 12 pure nonpolar hydrocarbons, 6 hydrocarbon mixtures, and 3 crude oils are measured at temperatures from 283.15 K up to 343.15 K and at 0.1 MPa. The measured refractive indices are used to calculate α P for a wide range of temperatures using the proposed method, and the measured densities are used to calculate α P for comparison. Reported densities and refractive indices of benzene at 298.15 K and at pressures up to 90 MPa are used for κ T evaluations with the proposed method. Values of α P and κ T calculated from refractive index measurements are in good agreement with experimental data and those determined from densities. This work aims to establish the foundation for experimental methods to determine volumetric properties of nonpolar hydrocarbon systems based on refractive index measurements. A high temperature and high pressure refractometer is expected to have multiple advantages over conventional techniques for density measurements, which include but are not limited to smaller amounts of sample needed, simpler calibration, faster measurement, and cells that are corrosion-resistant (i.e., sapphire glass).

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Temperature dependence of polarizability of diatomic homonuclear molecules

Cited by 20 publications

References 16 publications

Achieving High Dielectric Constant and Low Loss Property in a Dipolar Glass Polymer Containing Strongly Dipolar and Small-Sized Sulfone Groups

Achieving High Dielectric Constant and Low Loss Property in a Dipolar Glass Polymer Containing Strongly Dipolar and Small-Sized Sulfone Groups

Measured relationship between thermodynamic pressure and refractivity for six candidate gases in laser barometry

Determination of Volumetric Properties Using Refractive Index Measurements for Nonpolar Hydrocarbons and Crude Oils

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