Microwave absorption and dielectric relaxation of some rigid molecules and their mixtures

1977 ◽  
Vol 55 (10) ◽  
pp. 878-883 ◽  
Author(s):  
M. P. Madan ◽  
M. Shelfoon ◽  
I. Cameron
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Loss Factor ◽  
Relaxation Times ◽  
Liquid Mixtures ◽  
Polar Component ◽  
Simple Liquid ◽  
Dielectric Data ◽  
Dielectric Constant And Loss ◽  
Activated State

The dielectric constant and loss factor of some rigid molecules, pyridine, quinoline, and isoquinoline, and their mixtures have been measured in dilute benzene solutions in the microwave region over a range of temperatures. The dielectric data have been used to determine the relaxation times and the thermodynamic parameters for the activated state. The values of the relaxation time for single polar component solutions agree well at temperatures at which there are available known data. The relaxation times for the mixtures are consistent with the results on simple liquid mixtures of polar molecules in dilute solutions which were previously studied by us and by some other workers.

Microwave Absorption and Relaxation Processes of Some Monosubstituted Benzenes and their Mixtures

1973 ◽  
Vol 51 (17) ◽  
pp. 1815-1822 ◽  
Author(s):  
M. P. Madan
Keyword(s):  
Reasonable Agreement ◽  
Molecular Motion ◽  
Relaxation Times ◽  
Liquid Mixtures ◽  
Polar Component ◽  
Relaxation Processes ◽  
Simple Liquid ◽  
Dielectric Absorption ◽  
Dielectric Data ◽  
Monosubstituted Benzenes

The dielectric absorption of benzene solutions of some monosubstituted benzenes and their mixtures has been studied in the microwave region over a temperature range 6 to 60 °C. The relaxation times and the thermodynamic parameters for the activated states have been determined using the measured dielectric data. The results obtained have been discussed in terms of the molecular motion of the system. The values of relaxation time for single polar component solutions are in reasonable agreement at temperatures at which there are available known data. The relaxation times for the mixtures are consistent with the results obtained by other workers for simple liquid mixtures of polar molecules in dilute solutions which they investigated.

Relaxation processes of quinoline, isoquinoline, and their mixtures

1980 ◽  
Vol 58 (1) ◽  
pp. 20-24 ◽  
Author(s):  
M. P. Madan
Keyword(s):  
Thermodynamic Parameters ◽  
Molecular Motion ◽  
Polar Solvent ◽  
Relaxation Times ◽  
Relaxation Processes ◽  
Polar Components ◽  
Dielectric Absorption ◽  
System A ◽  
Dielectric Data ◽  
Activated State

The dielectric absorption of quinoline, isoquinoline, and their binary mixtures has been studied in the microwave region over a range of temperatures in dilute benzene and n-heptane solutions. The relaxation times and the thermodynamic parameters for the activated state have been determined using the measured dielectric data. The results obtained have been discussed in terms of the molecular motion of the system. A relation has been proposed to represent the relaxation behavior of a system of two Debye-type polar components in a non-polar solvent. The relation has been tested by comparing the calculated values with those determined experimentally for a few systems consisting of similar, simple rigid polar molecules.

Microwave Relaxation and Association of 3,5 Dimethyl 3-Hexanol

1970 ◽  
Vol 25 (11) ◽  
pp. 1685-1687
Author(s):  
F. F. Hanna ◽  
K. N. Abd-El-Nour
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Dielectric Loss ◽  
Relaxation Times ◽  
Concentrated Solutions ◽  
Short Relaxation Time

Abstract The dielectric constant (ε′) and dielectric loss (ε′′) of 3,5 dimethyl 3-hexanol in heptane have been measured for dilute and concentrated solutions at five wavelengths between 25 cm and 2 mm and at 20°, 40° and 60 °C. The data have been analysed and two relaxation times are obtained. The long relaxation time is attributed to the rotation of the whole molecule and the short relaxation time to the relaxation of the OH-group. For the range of concentrations used, the results show that associates are hardly detectable.

Microwave Absorption and Relaxation Behavior of Some Simple Ketones in Dilute Solutions

1975 ◽  
Vol 53 (1) ◽  
pp. 23-28 ◽  
Author(s):  
M. P. Madan
Keyword(s):  
Relaxation Time ◽  
Thermodynamic Parameters ◽  
Microwave Absorption ◽  
Reasonable Agreement ◽  
Relaxation Times ◽  
Relaxation Behavior ◽  
The Other ◽  
Dielectric Absorption ◽  
Dielectric Data ◽  
Thermodynamic Processes

The dielectric absorption of solutions of 2-hexanone, 4- and 5-nonanone, and 2-decanone has been examined in the microwave region over a range of temperatures in n-heptane, cyclohexane, and benzene. The relaxation times and the thermodynamic parameters for the activated states have been determined using the measured dielectric data. The values of relaxation time are in reasonable agreement at the temperature at which there are available known data. Both the relaxation behavior and the thermodynamic processes are discussed and, where possible, compared with corresponding results of the other workers.

Dielectric studies. Part XX. Molecular relaxation of some heterocyclic amines in dilute solution

1968 ◽  
Vol 46 (14) ◽  
pp. 2369-2372 ◽  
Author(s):  
J. Crossley ◽  
S. Walker
Keyword(s):  
Relaxation Time ◽  
Dipole Moments ◽  
Relaxation Times ◽  
Lone Pair ◽  
Intermolecular Forces ◽  
Dilute Solution ◽  
Microwave Frequencies ◽  
Heterocyclic Molecules ◽  
Dielectric Constant And Loss ◽  
The Difference

Dielectric constant and loss data have been obtained at microwave frequencies for acridine, 4-methyl-pyridine, phthalazine, quinoline, and isoquinoline in both cyclohexane and p-xylene solution. The data have been used to calculate relaxation times and apparent dipole moments. For phthalazine, quinoline, and isoquinoline in cyclohexane at 50 °C the distribution coefficient is zero and their relaxation times are very similar. Although the axes about which these three molecules may relax lead to different volumes being swept out, no variation in relaxation behavior has been detected, and each system can be characterized by one relaxation time. The relaxation times for all the heterocyclic molecules except quinoline and acridine in p-xylene are appreciably longer than in cyclohexane. Relaxation time values appear a sensitive means of detecting the weak molecular interaction between the amine and the p-xylene. The difference in behavior between the quinoline and acridine as opposed to isoquinoline could be attributed to a more appreciable steric effect in the former two, hindering the approach of the π-electrons of the p-xylene molecules to the hybridized lone pair on the nitrogen atom. No interaction is, in fact, detectable in the case of quinoline and acridine. The importance of allowing for weak intermolecular forces, even in dilute solution, when relaxation values are being anticipated, is emphasized.

scholarly journals An Experimental Study on the Dielectric Properties of Rubber Materials

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2908
Author(s):  
Hailong Chen ◽  
Yudong Xu ◽  
Mengqi Liu ◽  
Tao Li
Keyword(s):  
Experimental Study ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Loss Factor ◽  
Peak Frequency ◽  
Mixing Process ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Internal Mixing ◽  
Dielectric Constant And Loss

According to specific formulas, the mixing of rubber samples occurs by two methods: open mixing and internal mixing. The effects of frequency, mixing process, carbon black (CB) content, zinc oxide (ZnO) content, and stearic acid (SA) content on the dielectric properties of rubber materials were studied. The results showed that the effects of the mixing process on the dielectric properties of the rubber samples cannot be ignored, and the appropriate mixing process should be selected when preparing the required rubber materials. The dielectric constant and loss factor of the rubber samples vary depending on the frequency. The dielectric constant had a peak and valley value, while the loss factor only had a peak. The dielectric constant and loss factor of rubber samples were significantly affected by the content of CB, ZnO, and SA. The peak frequency decreased with the increase in CB content, however, the dielectric constant increased with an increase in CB content. The higher the ZnO content, the lower the peak frequency. In addition, the dielectric constant and loss factor increased with an increase in ZnO content. The higher the SA content, the greater the peak frequency. In addition, the dielectric constant and loss factor decreased with an increase in SA content. It is hoped that the experimental results obtained can provide guidance for the study of the dielectric properties, microwave absorption properties, and microwave heating characteristics of rubber polymers.

scholarly journals Computation of Dielectric constant and loss factor of 1-ethyl-3-methylimidazolium chloride (emim)

2020 ◽  
Vol 7 (1) ◽  
pp. 110-116
Author(s):  
Lubis Satzen ◽  
Samson D. Yusuf ◽  
Abdulmumini Z. Loko ◽  
Lucas W. Lumbi
Keyword(s):  
Dielectric Constant ◽  
Loss Factor ◽  
Dielectric Constant And Loss

scholarly journals Dielectric Relaxation Studies Between Brompheniramine with 1-Butanol, 1-Pentanol and 1-Hexanol at 303K

2020 ◽  
Vol 17 (3) ◽  
pp. 230-235
Author(s):  
Sampandam Elangovan ◽  
Tilahun Diriba Garbi ◽  
Senbeto Kena Etana
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Intermolecular Interaction ◽  
Research Work ◽  
Liquid Mixtures ◽  
Time Domain Reflectometry ◽  
Dielectric Relaxation Time ◽  
Pharmaceutical Industries ◽  
Relaxation Studies

The dielectric relaxation studies are vital in analyzing the strength of the inter molecular interaction between the binary liquid systems [1-4]. Jyostna et al. [5] reported thermodynamic parameters of isoamyl alcohols and mono clinic aromatic liquid mixtures. Shakila et al. [6] studied the dielectric properties of aromatic alcohols and aliphatic amines at different temperatures. In general, dielectric relaxation time varies with the inter molecular forces acting between the molecules in the selected liquid mixtures. Brompheniramine is one of the critical compounds of an amine group with spectacular applications, including pharmaceutical industries [7]. Higher carbon chain length alcohols are having self associated and proton donating ability in the liquid mixtures. The variations in the dielectric constant (є’), dielectric loss (є’’), static dielectric constant (є0) and the dielectric constant at an optical frequency (є∞) with a range of brompheniramine concentrations with 1-butanol,1-pentanol and 1-hexanol systems are useful in the applied research and chemical industries. Moreover, the variations in the dielectric constant and dielectric relaxation time should be useful in the analysis of intermolecular interaction between the functional group of the selected liquid mixtures. This research work attempts to analyse the intermolecular interaction between the brompheniramine and 1-butanol,1-pentanol and 1-hexanol at 303K using time domain reflectometry techniques.

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