V. I. Zhuravlev

Dielectric properties of polyhydric alcohols: Butanediols

The equilibrium and dynamic properties of 1,3-, 1,4-, and 2,3-butanediols were studied experimentally in the frequency range from 1 MHz to 36 GHz at temperatures from 283 to 423 K. The densities of the compounds were measured. The Kirkwood correlation factor was calculated with various (experimentally measured and calculated) dipole moments of the molecules.

A dielectric study of the structure of propylene glycol

The dielectric spectra of propylene glycol over the frequency and temperature ranges 10 mHz–75 GHz and 175–423 K, respectively, were analyzed using the Dissado-Hill cluster model. A correlation between relaxation processes of breaking and formation of intermolecular H-bonds in clusters was obtained. A correlation of fluctuation processes of synchronous exchange of molecules between neighboring clusters corresponded to the redistribution of H-bonds between them. The Dissado-Hill theory was used to determine the integral relaxation times, nDH and mDH parameters and calculate the mean dipole moments of propylene glycol clusters and the energy characteristics of processes of their rearrangement. The mean dipole moments of clusters (23617–18.65 D) were compared with those of molecules in the liquid phase (3.67–3.03 D). The apparent activation enthalpy of processes of cluster rearrangements decreased from 141.8 to 25.2 kJ/mol, the activation energy decreased from 46.03 to 18.47 kJ/mol, and the energy of orientation dipole-dipole interactions, from 3.78 to 3.45 kJ/mol as the temperature increased.

Dielectric Properties of Diols and Triols: 2,3-Butanediol

AbstractThe results of experimental studies of the dielectric properties of 2,3-butanediol are reported. Static dielectric constant εs was measured at 1 MHz; dielectric constant ε′ and dielectric loss ε′’ were determined by the balance method over the frequency range 2–37.5 GHz and the temperature range 293–423 K.

The dielectric properties of polyatomic alcohols: Asymmetric dispersion in butanediols

Static permittivity ɛs, permittivity ɛ′, and dielectric loss ɛ″ were measured for 1,3-, 1,4-, and 2,3-butanediols over the frequency and temperature ranges 1 MHz-36 GHz and 293–423 K. These equilibrium properties of butanediols were analyzed using the Onsager-Kirkwood-Fröhlich theory. The correlation factor g over the temperature range was calculated. The experimental permittivity ɛ′ and dielectric loss ɛ″ values were described by the Davidson-Cole equation. The relaxation times τD-C and parameter β of their distribution were calculated.

Relaxation processes of the structural rearrangement of clusters in liquids: 1,2-ethanediol, 1,2-propanediol, and 1,2,6-hexanetriol

The dielectric relaxation spectra (DRS) of 1,2-ethanediol, 1,2-propanediol, and 1,2,6-gexanetriol are analyzed in terms of the Dissado-Hill (DH) model in a wide range of temperatures, with all parameters required for calculating the cluster dipole moments being determined within the DH molecular model itself. The dependence of the equilibrium and relaxation properties of DRS on the hydrocarbon radical length and the number of OH groups is studied. The dipole moments of the clusters are calculated. It is shown how the roles of the processes of intracluster rearrangement are redistributed due to the break of hydrogen bonds and fluctuation processes of synchronous exchange of molecules between the clusters.

Correlation between the equilibrium and relaxation dielectric properties of 1,2-ethanediol

AbstractThe data on the dispersion of the permittivity ɛ*(ω) of 1,2-ethanediol over the temperature range 161–453 K and the frequency range 0.1 Hz–150 GHz were analyzed using the Dissado-Hill cluster model. The relaxation frequency ωp = τDH−1 and intra-(nDH) and intercluster (mDH) correlation parameters were calculated. The energy barrier to the libration of molecular axes in clusters was found to be BDH = 2.96 kJ/mol. The apparent enthalpy of activation was determined; it increased from ΔHDH exp# = 22.18 kJ/mol to ΔHDH exp# = 129.19 kJ/mol close to the glass transition temperature. The mean dipole moments

Temperature dependences of characteristics of 2,5-hexanediol and 1,2,6-hexanetriol cluster structures according to dielectric radiospectroscopy

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Dielectric properties of polyfunctional alcohols: 2,3-butanediol

of 1,2-ethanediol clusters were calculated; they decreased from 162920 to 18.08 D as the temperature increased from 161 to 453 K. According to approximate estimates, the number of 1,2-ethanediol molecules in a cluster