Dielectric relaxation study of hydrogen bonded structures in ethanolamine with diethanolamine using TDR technique

Patil, A.V.; Shinde, G. N.; Pawar, V.P.

doi:10.1016/j.molliq.2012.01.017

Cited by 25 publications

(9 citation statements)

References 26 publications

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“…The high-frequency spectra at high temperature are measured on liquid EAM, and display a relaxation peak in the microwave frequency region (between 10 8 and 10 9 Hz), commonly referred to as "structural relaxation", whose position is in rough agreement with previous studies. 55,56 This relaxation could be well described by a Cole-Cole function (Eq. 1) with an exponent c only slightly lower than unity.…”

Section: Phase Transitions In Eam and Analysis Of The Metastable And mentioning

confidence: 99%

Polymorphism with Conformational Isomerism and Incomplete Crystallization in Solid Ethanolamine

Romanini

Négrier

Tripathi

et al. 2019

Crystal Growth & Design

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We employ calorimetry, Rietveld refinement of X-ray powder diffraction, broadband dielectric spectroscopy and molecular dynamics simulations, to investigate the phase behavior, crystal structure, dc conductivity and dielectric response of the condensed phases of ethanolamine (EAM), an ethane derivative with two distinct hydrogen-bonding groups. EAM is found to exhibit, besides its stable crystal phase, a metastable crystalline phase obtained from the supercooled liquid phase. The metastable phase can only be maintained at low temperature; upon heating an irreversible exothermic transformation to the stable crystal structure takes place at 210 K, with a low transition enthalpy of ca. 2.4 J/g. The observed polymorphism is accompanied by differences in the molecular conformation and degree of structural order. Each EAM molecule participates in six H-bonds in both crystalline phases. While the stable phase is fully ordered, the metastable phase appears to be characterized by a statistical disorder in the position of the hydrogen atoms and thus of the intramolecular conformation and intermolecular hydrogen bonding. Our molecular dynamics simulations suggest that such disorder is dynamic in character, and allow analyzing the dynamic H-bonding motif of the metastable phase in terms of composition, length and energy of the H-bonds, and molecular conformations involved. Charge conduction is mainly ionic in both crystalline phases and exhibits the typical temperature dependence of disordered solid electrolytes, rather than crystalline ones. Dielectric characterization indicates that, upon crystallization of liquid EAM, a small fraction of the sample (approximately 5%) remains amorphous, a situation similar to that reported for other H-bonded systems such as glycerol and nbutanol.

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Section: Phase Transitions In Eam and Analysis Of The Metastable And mentioning

confidence: 99%

Polymorphism with Conformational Isomerism and Incomplete Crystallization in Solid Ethanolamine

Romanini

Négrier

Tripathi

et al. 2019

Crystal Growth & Design

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“…from the temperature profiles predicted by the modified force fields, and (c) calculated using equation 5 employing the dielectric spectra, bulk densities, and constant-pressure specific heats predicted by the modified force fields. The two experimental heating rate curves are based on experimental dielectric spectra collected at 278 K (blue squares) 33 and 308 K (red dots) 40 . The employed electric field amplitude is 0.01 V/Åfor all MW frequencies.…”

Section: Mw Heating Ratesmentioning

confidence: 99%

Molecular dynamics simulation of microwave heating of liquid monoethanolamine (MEA): An evaluation of existing force fields

Afify

Sweatman

2018

The Journal of Chemical Physics

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We present a complete classical molecular dynamics (MD) study of the dielectric heating of liquid monoethanolamine (MEA) at microwave (MW) frequencies ranging from 1.0 to 10.0 GHz. The detailed dielectric properties predicted by a series of existing empirical force fields of MEA were carefully compared to experimental results. We find that all the evaluated force fields were unable to accurately predict experimental static dielectric constant, frequency-dependent dielectric spectra, and MW heating profiles of liquid MEA, although GROMOS-aa (all-atom GROningen molecular simulation) is the most accurate of those tested. With an isotropic scaling of partial atomic charges, the modified GROMOS-aa and OPLS-aa (all-atom optimized potentials for liquid simulations) force fields could accurately reproduce the experimental static dielectric constant and frequency-dependent dielectric spectra, but they failed to predict MW heating rates directly from MD heating simulations. Thus, the recently presented approach [F. J. Salas et al., J. Chem. Theory Comput. 11, 683 (2015); A. P. de la Luz et al., ibid. 11, 2792 (2015)] to tune existing force fields is not an ideal approach to produce force fields suitable for accurate dielectric heating studies.

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“…21,22 The Tektronix model no. DSA8200 Digital Serial Analyzer sampling mainframe along with the sampling module 80E08 has been used for the TDR.…”

Section: Materials and Measurementsmentioning

confidence: 99%

Dielectric properties of benzylamine in 1,2,6-hexanetriol mixture using time domain reflectometry technique

Swami¹,

Hudge

Pawar³

2016

J. Adv. Dielect.

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The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry (TDR) technique in the frequency range of 10 MHz to 30 GHz. Complex permittivity spectra were fitted using Havriliak-Negami equation. By using least square fit method the dielectric parameters such as static dielectric constant (" 0 ), dielectric constant at high frequency (" 1 ), relaxation time (ps) and relaxation distribution parameter () were extracted from complex permittivity spectra at 25 C. The intramolecular interaction of different molecules has been discussed using the Kirkwood correlation factor, Bruggeman factor. The Kirkwood correlation factor (g f ) and effective Kirkwood correlation factor (g eff ) indicate the dipole ordering of the binary mixtures.

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Dielectric relaxation study of hydrogen bonded structures in ethanolamine with diethanolamine using TDR technique

Cited by 25 publications

References 26 publications

Polymorphism with Conformational Isomerism and Incomplete Crystallization in Solid Ethanolamine

Polymorphism with Conformational Isomerism and Incomplete Crystallization in Solid Ethanolamine

Molecular dynamics simulation of microwave heating of liquid monoethanolamine (MEA): An evaluation of existing force fields

Dielectric properties of benzylamine in 1,2,6-hexanetriol mixture using time domain reflectometry technique

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