The dielectric behaviour of dipolar mixtures I: chlorobenzene–nitrobenzene mixtures

1986 ◽  
Vol 64 (11) ◽  
pp. 1534-1536 ◽  
Author(s):  
F. F. Hanna ◽  
K. N. Abdel-Nour ◽  
A. M. Ghoneim
Keyword(s):  
Relaxation Time ◽  
Thermodynamic Parameters ◽  
Relaxation Times ◽  
Dielectric Behaviour ◽  
Dilute Solutions ◽  
Single Relaxation Time ◽  
Microwave Region ◽  
Dielectric Absorption

The dielectric absorption of dilute solutions of nitrobenzene, chlorobenzene, and their mixtures in cyclohexane and Decalin® have been measured in the microwave region at three temperatures between 20 and 40 °C. The relaxation times and thermodynamic parameters are determined. A single relaxation time is found for the mixtures, and the results are discussed.

Relaxation processes of some simple aliphatic molecules in dilute solutions

1977 ◽  
Vol 55 (4) ◽  
pp. 297-301 ◽  
Author(s):  
M. P. Madan
Keyword(s):  
Carbon Tetrachloride ◽  
Dielectric Relaxation ◽  
Thermodynamic Parameters ◽  
Relaxation Times ◽  
Relaxation Processes ◽  
Dilute Solutions ◽  
Microwave Region ◽  
Nonpolar Solvents ◽  
Dielectric Data ◽  
Intramolecular Rotation

The dielectric relaxation processes of acetone, cyclohexanone, 4-methyl-2-pentanone, and 4-heptanone in dilute nonpolar solvents, n-heptane, cyclohexane, benzene, and carbon tetrachloride have been studied in the microwave region over a temperature range 10 to 60 °C. The relaxation times and the thermodynamic parameters for the activated states have been determined using the measured dielectric data. The results have been discussed in terms of dipole reorientation by molecular and intramolecular rotation and compared, wherever possible, with other similar studies on aliphatic molecules.

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.

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.

Dielectric relaxation of nitromethane, some nitriles, and their mixtures in dilute solutions

1987 ◽  
Vol 65 (12) ◽  
pp. 1573-1576 ◽  
Author(s):  
M. P. Madan
Keyword(s):  
Refractive Index ◽  
Dielectric Relaxation ◽  
Thermodynamic Parameters ◽  
Molecular Motion ◽  
Empirical Relation ◽  
Relaxation Times ◽  
Relaxation Behaviour ◽  
Polar Components ◽  
Dielectric Absorption ◽  
Activated State

The dielectric absorption of nitromethane, benzonitrile, and acetonitrile and their binary mixtures has been studied in the microwave region over a range of temperatures in dilute benzene solutions. The data on static and optical permittivities at 20 °C have also been obtained, from measurements at 100 kHz and from measuring the refractive index for sodium-D lines, for a few cases. These data have been used to determine the relaxation times and the thermodynamic parameters for the activated state. The results obtained have been discussed in terms of the molecular motion of the systems. A new empirical relation has been proposed to represent the relaxation behaviour of a system of two Debye-type polar components in a nonpolar solvent. The relation has been tested, along with a previously suggested relation, by comparing the calculated values with those determined experimentally.

KINETIC STUDIES OF PROTEIN–DYE AND ANTIBODY–HAPTEN INTERACTIONS WITH THE TEMPERATURE-JUMP METHOD

1962 ◽  
Vol 40 (9) ◽  
pp. 1786-1797 ◽  
Author(s):  
A. Froese ◽  
A. H. Sehon ◽  
M. Eigen
Keyword(s):  
Relaxation Time ◽  
Bovine Serum Albumin ◽  
Rate Constants ◽  
Temperature Jump ◽  
Relaxation Times ◽  
Kinetic Studies ◽  
Single Relaxation Time ◽  
Effects Of Temperature ◽  
Arsonic Acid ◽  
Kinetics Of

The kinetics of protein–dye and antibody–hapten reactions were studied with the temperature-jump method. The systems used consisted of (i) bovine serum albumin (BSA) and the dye 1-naphthol-4-[4-(4′-azobenzene azo)phenyl arsonic acid], referred to as N—R′, (ii) BSA and the dye 1-naphthol-2-sulphonic acid-4-[4-(4′-azobenzene azo)phenyl arsonic acid], referred to as NS—R′, and (iii) rabbit antibodies to phenyl arsonic acid [Ab] and the hapten N—R′.Each of the systems exhibited a single relaxation time. From the analysis of the concentration dependence of the relaxation times, it was concluded that each system could be represented by the reactions[Formula: see text]where P refers to BSA or Ab, and D to N—R′ or NS—R′. The following rate constants were calculated for the three systems at 25 °C:[Formula: see text]The effects of temperature and pH on the rate constants of the system BSA – N—R′ are discussed.

Dielektrische Absorption von Alkoholen und Phenolen in verdünnter Lösung bei Mikro- und Sub-mm-Wellen / Dielectric Absorption of Microwaves and Submillimeterwaves by Alcohols and Phenols in Dilute Solution

1977 ◽  
Vol 32 (12) ◽  
pp. 1512-1520
Author(s):  
A. Camacho Beitrán ◽  
G. Klages
Keyword(s):  
Relaxation Time ◽  
Relaxation Times ◽  
Hydroxyl Group ◽  
Dilute Solution ◽  
Aromatic Solvent ◽  
Dielectric Absorption ◽  
First Approximation ◽  
Wave Region ◽  
Wave Range ◽  
Solvent Molecules

Abstract Dielectric Absorption of Microwaves and Submillimeterwaves by Alcohols and Phenols in Dilute Solution Dielectric lossers of benzylaleohol, cyclohexanol, n-decanol, and diphenylcarbinol and also of phenol, p-cresol, 2,4,6-trimethylphenoI and diphenylether have been measured over the 1 to 300 GHz frequency band using aliphatic and aromatic solvents. In cyclohexane solutions, measurements have also been made at two frequencies in the sub-mm-wave range. From an analysis of the absorption curves a distribution of relaxation times is obtained in a first approximation. Comparing the results from 3 alcohols and 3 phenols, differences are found between the relaxation time of the hydroxyl group and the live time of hydrogen bonds to aromatic solvent molecules. More than one relaxation time is found in diphenylether and its absorption curve in cyclohexane has a slope steeper than a Debye curve in the sub-mm-wave region, which is discussed as inertial effect.

Dielectric studies. Part XVIII. Dipole moments and relaxation times of some symmetrically substituted alkylbenzenes

1968 ◽  
Vol 46 (6) ◽  
pp. 847-851 ◽  
Author(s):  
J. Crossley ◽  
S. Walker
Keyword(s):  
Relaxation Time ◽  
Dipole Moments ◽  
Relaxation Times ◽  
Pure Liquid ◽  
Dielectric Studies ◽  
Molecular Reorientation ◽  
Microwave Frequencies ◽  
Short Relaxation Time ◽  
Dielectric Absorption ◽  
Liquid Benzene

The dielectric absorption at four microwave frequencies of pure liquid benzene and p-cymene at 25 °C, p-xylene and mesitylene at 25, 40, 50, and 60 °C, and solutions of durene and hexamethylbenzene in mesitylene at 60 °C has been examined. All show measurable loss factors and apparent dipole moments of about 0.1 to 0.2 D. These moments are less in magnitude than those associated with the short relaxation time (τ2) process for the polar monoalkylbenzenes. o-xylene and m-xylene. Their relaxation times are too short for molecular reorientation and there is a rough correlation between the number of collisions/molecule s and the reciprocal relaxation time.

Dielectric relaxation of some aliphatic ester molecules in solutions

1979 ◽  
Vol 57 (7) ◽  
pp. 1035-1038 ◽  
Author(s):  
M. P. Madan
Keyword(s):  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Relaxation Times ◽  
Activation Parameters ◽  
Dielectric Absorption ◽  
Aliphatic Ketones ◽  
Dielectric Data ◽  
Aliphatic Ester ◽  
Aliphatic Esters ◽  
Intramolecular Rotation

The dielectric absorption of several aliphatic esters 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 have been determined using the measured dielectric data. The values of the relaxation time for those solutions for which there are available known data agree well with other determinations. The relaxation times and the various molar activation parameters have been discussed in terms of dipole reorientation by molecular and intramolecular rotation. It would appear that the relaxation behavior of aliphatic esters is similar to that for other aliphatic molecules, such as aliphatic ketones studied previously.

THEORY OF POLYMER RELAXATION TIMES IN SEMI-DILUTE SOLUTIONS

1995 ◽  
Vol 09 (01) ◽  
pp. 57-67 ◽  
Author(s):  
YASUHIRO SHIWA
Keyword(s):  
Relaxation Time ◽  
Hydrodynamic Interaction ◽  
Relaxation Times ◽  
Excluded Volume ◽  
Dilute Solutions ◽  
Gradual Reduction ◽  
Polymer Relaxation ◽  
Dilute Polymer Solutions ◽  
Continuous Approach ◽  
Crossover Behavior

The explicit crossover behavior of the longest relaxation time for the dilute and semi-dilute polymer solutions is presented. Gradual reduction of the excluded-volume and the hydrodynamic interaction due to screening is taken into account along with the entanglement effect. The result reveals a continuous approach to a reptation-like asymptote with increasing concentration.

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