Relaxation phenomena of nicotinamide and benzamide with 1-propanol and 1-butanol in C6H6 under static and 9.385 GHz electric field

2016 ◽  
Vol 94 (7) ◽  
pp. 628-639 ◽  
Author(s):  
Swagatadeb Sahoo ◽  
Swapan K. Sit
Keyword(s):  
Electric Fields ◽  
Liquid Mixture ◽  
Dipole Moments ◽  
Relaxation Times ◽  
Relaxation Mechanism ◽  
Debye Model ◽  
Relaxation Phenomena ◽  
Debye Relaxation ◽  
Polar Groups ◽  
Polar Mixtures

Dielectric relaxation behaviors of nicotinamide+1-propanol, benzamide+1-propanol, and nicotinamide+1-butanol dissolved in C6H6 at 0.990, 0.985, 0.980, 0.975, 0.970; 0.990, 0.985, 0.980, and 0.980 mol fraction xj of 1-propanol or 1-butanol at temperature 30 °C and 30, 40, 50, and 60 °C, respectively, are studied using the Debye model of binary polar–non-polar liquid mixture to predict double relaxation times τ2 and τ1 and dipole moments μ2 and μ1 from susceptibility measurement of concentration variation solution data under static and 9.385 GHz electric fields. Nineteen systems exhibit τ2, τ1 and μ2, μ1. τ2 are found to increase with temperature for all the binary polar mixtures, whereas τ1, most probable τ0, and measured τ from slope methods are almost the same. They agree well with the τ reported by Higasi. The plots of τjk–xj and μjk–xj curves reveal solute–solute and solute–solvent molecular association through H-bonding, and variation of μ with t (°C) is noted from the μjk–t curve. The associational aspects are taken into consideration from theoretical μtheo from the standpoint of inductive, mesomeric, and electromeric effects within the polar groups of the molecules. The estimated Debye factor τjkT/η and Kalman factor τjkT/ηγ reveal that the polar mixture obeys the Debye relaxation mechanism.

Electric Field Guided Self-Assembly of Molecules

2006 ◽  
Vol 947 ◽  
Author(s):  
Wei Lu ◽  
David Salac
Keyword(s):  
Electric Fields ◽  
Self Assembly ◽  
Dipole Moments ◽  
Substrate Surface ◽  
Feature Size ◽  
Multilayer Systems ◽  
Polar Groups ◽  
Novel Approach ◽  
Dipolar Molecules ◽  
Dynamic Domain

ABSTRACTAdsorbate molecules usually carry electric dipole moments, and the magnitude can be engineered by adding polar groups. This paper investigates the dynamic domain pattern formation of multilayer dipolar molecules on a substrate under the guidance of external electric fields. The simulations reveal self-alignment, pattern conformation and the reduction of feature size in multilayer systems. A novel approach of transporting molecules on a substrate surface by reconfigurable molecular vehicles and embedded electrodes is proposed.

Dielectric relaxation of acetyl- and benzoyl-acetones

1989 ◽  
Vol 67 (5) ◽  
pp. 804-808 ◽  
Author(s):  
R. K. Khanna ◽  
Abha Bhatnagar
Keyword(s):  
Dielectric Relaxation ◽  
Dipole Moments ◽  
Relaxation Times ◽  
Weight Fraction ◽  
Relaxation Mechanism ◽  
Relaxation Processes ◽  
Dielectric Absorption ◽  
Molar Polarization ◽  
Distribution Parameters ◽  
Few Data

Dielectric absorption measurements are reported at radio and microwave frequencies (at six different wavelengths) for acetylacetone and benzoylacetone solutions in benzene, in a temperature range 25–60 °C. Analysis of dielectric data in terms of Cole–Cole arc plots and multiple relaxation processes reveals that, at higher temperatures, overall molecular relaxation is the dominant relaxation mechanism in these β-diketones. The observed relaxation times, distribution parameters, and dipole moments are in reasonable agreement with the few data reported for some temperatures, in the literature. The activation energy parameters are also evaluated assuming dielectric relaxation to be a rate process. Molar polarization vs. weight fraction (concentration) plots show anomalous behaviour for acetylacetone. Keywords: dielectric properties, dielectric losses, relaxation times, dipole moment, dielectric absorption and dispersion, microwave measurements.

scholarly journals Non-Debye Relaxations: Two Types of Memories and Their Stieltjes Character

Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 477
Author(s):  
Katarzyna Górska ◽  
Andrzej Horzela
Keyword(s):  
Stochastic Processes ◽  
Spectral Function ◽  
Evolution Equations ◽  
Memory Function ◽  
Relaxation Phenomena ◽  
Stieltjes Function ◽  
Infinitely Divisible ◽  
Spectral Functions ◽  
Debye Relaxation ◽  
Relaxation Functions

In this paper, we show that spectral functions relevant for commonly used models of the non-Debye relaxation are related to the Stieltjes functions supported on the positive semi-axis. Using only this property, it can be shown that the response and relaxation functions are non-negative. They are connected to each other and obey the time evolution provided by integral equations involving the memory function M(t), which is the Stieltjes function as well. This fact is also due to the Stieltjes character of the spectral function. Stochastic processes-based approach to the relaxation phenomena gives the possibility to identify the memory function M(t) with the Laplace (Lévy) exponent of some infinitely divisible stochastic processes and to introduce its partner memory k(t). Both memories are related by the Sonine equation and lead to equivalent evolution equations which may be freely interchanged in dependence of our knowledge on memories governing the process.

scholarly journals Multiscale Post-Seismic Deformation Based on cGNSS Time Series Following the 2015 Lefkas (W. Greece) Mw6.5 Earthquake

2021 ◽  
Vol 11 (11) ◽  
pp. 4817
Author(s):  
Filippos Vallianatos ◽  
Vassilis Sakkas
Keyword(s):  
Time Series ◽  
Relaxation Time ◽  
Relaxation Times ◽  
Relaxation Mechanism ◽  
Mesoscopic Scale ◽  
Macroscopic Scale ◽  
Epicentral Area ◽  
Arrhenius Dependence ◽  
Seismic Deformation ◽  
Logarithmic Type

In the present work, a multiscale post-seismic relaxation mechanism, based on the existence of a distribution in relaxation time, is presented. Assuming an Arrhenius dependence of the relaxation time with uniform distributed activation energy in a mesoscopic scale, a generic logarithmic-type relaxation in a macroscopic scale results. The model was applied in the case of the strong 2015 Lefkas Mw6.5 (W. Greece) earthquake, where continuous GNSS (cGNSS) time series were recorded in a station located in the near vicinity of the epicentral area. The application of the present approach to the Lefkas event fits the observed displacements implied by a distribution of relaxation times in the range τmin ≈3.5 days to τmax ≈350 days.

scholarly journals Microwave Assisted Synthesis of Organic Compounds and Nanomaterials

2021 ◽  
Author(s):  
Anjali Jha
Keyword(s):  
Green Chemistry ◽  
Organic Synthesis ◽  
Electric Fields ◽  
Chemical Reactions ◽  
Dipole Moments ◽  
Electric Heating ◽  
Microwave Assisted Synthesis ◽  
Microwave Chemistry ◽  
Microwave Assisted ◽  
Promising Area

In the Conventional laboratory or industry heating technique involve Bunsen burner, heating mental/hot plates and electric heating ovens. To produce a variety of useful compounds for betterment of mankind, the Microwave Chemistry was introduced in year 1955 and finds a place in one of the Green chemistry method. In Microwave chemistry is the science of applying microwave radiation to chemical reactions. Microwaves act as high frequency electric fields and will generally heat any material containing mobile electric charges, such as polar molecules in a solvent or conducting ions in a solid. Polar solvents are heated as their component molecules are forced to rotate with the field and lose energy in collisions i.e. the dipole moments of molecules are important in order to proceed with the chemical reactions in this method. It can be termed as microwave-assisted organic synthesis (MAOS), Microwave-Enhanced Chemistry (MEC) or Microwave-organic Reaction Enhancement synthesis (MORE). Microwave-Assisted Syntheses is a promising area of modern Green Chemistry could be adopted to save the earth.

Zur Protonenrelaxation von Wasser an Silikagelen

1967 ◽  
Vol 22 (11) ◽  
pp. 1751-1760 ◽  
Author(s):  
D. Michel
Keyword(s):  
Water Clusters ◽  
Relaxation Times ◽  
Dipolar Interaction ◽  
Relaxation Mechanism ◽  
Silica Gels ◽  
Proton Relaxation ◽  
Relaxation Rates ◽  
Proton Proton ◽  
Adsorbed Molecules ◽  
Paramagnetic Impurities

In most cases the proton relaxation of adsorbed liquids and gases is caused by the proton-proton dipolar interaction and the coupling between protons and paramagnetic impurities (e. g. Fe3+-ions) of the adsorbent. The latter relaxation mechanism, however, has been neglected up till now although in some commercial silica gels it’s contribution can be the most important one (see Section 2.2). Consequently, motional phenomena of adsorbed molecules can only be studied by NMR techniques if the relative largeness of these two relaxation rates has been estimated, as can be done by investigating the dependence of proton relaxation-times on the H/D-ratio. Relaxation-time measurements in the temperature range from —100° to +80°C indicate that proton transfers occur between surface hydroxils and adsorbed particles. In a sample of 3/4 statistical monolayer the presence of two different types of water, clusters containing 95% of the adsorbed molecules with correlation time τc2=2.7 · 10-10 s (0°C), and more individually adsorbed particles with τc1 ⪆ 2.3 ·10-8 (0°C), has been inferred (see Section 2.1).

Effect of Dielectric Imperfections on the Electroactive Deformations of Polar Dielectric Elastomers

2019 ◽  
Vol 86 (8) ◽  
Author(s):  
Yanhui Jiang ◽  
Yang Liu
Keyword(s):  
Dielectric Permittivity ◽  
Shear Modulus ◽  
Electric Fields ◽  
Nonlinear Deformation ◽  
Dielectric Elastomers ◽  
Inhomogeneous Deformation ◽  
Polar Dielectric ◽  
Polar Groups ◽  
Deformation Stability ◽  
Potential Applications

We find that the ratio of dielectric permittivity to shear modulus is linearly related to the number of polar groups per polymer chain in polar dielectric elastomers (PDEs). Our discovery is verified via computational modeling and validated by experimental evidences. Based on the finding, we introduce the new concept of dielectric imperfection (DI) and provide some physical insights into understanding it through demonstrating the large nonlinear deformation of PDEs with DIs under electric fields. The results show remarkable DI-induced inhomogeneous deformation and indicate that the size and dielectric permittivity of DIs have a significant impact on the deformation stability of PDEs under electric fields. With this concept, we propose some potential applications of PDEs with DIs.

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