Dielectric Relaxation in Ethylene Glycol - Dimethyl Sulfoxide Mixtures as a Function of Composition and Temperature

Abstract

ABSTRACT. Using time domain reflectometry, the complex dielectric spectra between 10 MHz to 20 GHz has been measured in the whole composition range at 10, 20, 30 and 40 o C for the binary mixtures of ethylene glycol and dimethyl sulfoxide. For all the mixtures, only one dielectric loss peak was observed in this frequency range. The relaxation in these mixtures can be described by a single relaxation time using the Debye model. A systematic variation is observed in dielectric constant (ε0) and relaxation time (τ). The excess permittivity (ε E ), excess inverse relaxation time (1/τ) E , Kirkwood correlation factor (g) and thermodynamic parameters viz. enthalpy of activation (∆H) and Gibbs free energy of activation (∆G) have been determined, to confirm the formation of hydrogen bonded homogeneous and heterogeneous cooperative domains, the dynamics of solute -solute interaction and the hindrance to molecular rotation in the hydrogen bonded glass forming ethylene glycol -dimethyl sulphoxide system.

A Co(III) Complex of 1-Amino-4-hydroxy-9,10-anthraquinone Exhibits Apoptotic Action against MCF-7 Human Breast Cancer Cells

“…In anhydrous DMF, under similar experimental conditions, CoQ 3 undergoes three-one electron reductions having peak potentials ( E pc ) at −1.025, −1.225, and −1.475 V, respectively, with the corresponding formal potentials ( E ) being −0.950, −1.195, and −1.405 V, respectively ( Figure 6 and Table 1 ). Considering the fact that the polarity of DMF is less than that of DMSO 51 and comparing the three reduction potentials of CoQ 3 in the two solvents, it can be said that with the increasing polarity of the medium, reduction potentials move in a positive direction and that reductions become more feasible as the polarity of solvent increases. This means stability of the formed semiquinone species is increased with an increase in the polarity of the medium.…”

“…Dimethyl sulfoxide (DMSO) (99.0%, Spectrochem, India) was first dried over fused CaCl 2 for 3–4 days, decanted, and then distilled under reduced pressure. 51 The distilled sample was preserved in a well-stoppered Jena bottle in desiccators and redistilled again before use. N , N -Dimethyl formamide (DMF) (99.5%, Spectrochem, India) (LR, BDH) was purified 52 first by distilling under reduced pressure in a N 2 atmosphere and then preserving the distillate over dry K 2 CO 3 (Merck) for a week.…”

Modeling, design, and synthesis of gram-scale monodispersed silver nanoparticles using microwave-assisted polyol process for metamaterial applications

“…Their experiments results show a maximum of at the frequencies of 1.64 GHz, 2 GHz, 3 GHz, and 4 GHz at temperatures of 25℃, 35℃, 45℃, and 55℃, respectively. Also, Undre et al [46] measured the dielectric properties of EG at 20℃. We can see the dielectric loss peak for EG in the frequency range from approximately 1.2 to 2 GHz.…”

Preliminary Results of a New Auxiliary Mechatronic Near-Field Radar System to 3D Mammography for Early Detection of Breast Cancer

“…As the first attempt, permittivity and conductivity behavior of binary aqueous mixtures of sodium chloride [ 124 ], ethanol [ 125 ], DMSO [ 126 ], DESO [ 127 ], glycine [ 128 ], ethylene glycol oligomer [ 129 ], 2-butoxyethanol [ 130 ], butyric acid [ 131 ], and 2-methoxyethanol [ 132 ] were reviewed. Later, other chemical compounds or their non-aqueous mixtures were also considered; among which methanol, 1-propanol, 2-propanol [ 133 ], dialkyl carbonates [ 134 ], 1-Hexanol/1-propenol [ 135 ], lithium salts/dimethyl carbonate [ 136 ], ethylene glycol - dimethyl sulfoxide [ 137 ], morpholine/n-butanol, and C16-ether-PN6-1ecith/methanol [ 131 ] can be named. Last efforts constituted reviewing a Ketone-like chemical, Dimethylketone (DMK), in mixture with 2–Butoxyethanol (2-BE) [ 138 ] and corn syrup [ 139 ].…”