Theory of Concentration Dependence of Polymer Relaxation Times in Dilute Solutions

1978 ◽  
Vol 11 (5) ◽  
pp. 843-852 ◽  
Author(s):  
M. Muthukumar ◽  
Karl F. Freed
Keyword(s):  
Concentration Dependence ◽  
Relaxation Times ◽  
Dilute Solutions ◽  
Polymer Relaxation

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.

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.

Self-Association of Cholesterol in Carbon Tetrachloride

1979 ◽  
Vol 34 (3) ◽  
pp. 369-374 ◽  
Author(s):  
M. Kunst ◽  
D. van Duijn ◽  
P. Bordewijk
Keyword(s):  
Dipole Moment ◽  
Carbon Tetrachloride ◽  
Concentration Dependence ◽  
Equilibrium Constants ◽  
Molar Fraction ◽  
Dilute Solutions ◽  
Dielectric Parameters ◽  
Moment Equilibrium ◽  
Self Association

Abstract Analysis of infrared hydroxyl multimer absorbances of dilute solutions of cholesterol in carbon tetrachloride as a function of the monomer absorbance strongly favours the interpretation of the association of this alcohol with a monomer-dimer-tetramer model up to a molar fraction of 0.012. This model also explains very well the concentration dependence of the apparent dipole moment. Equilibrium constants and dielectric parameters have been determined. Suggestions about the structure of the various associates are made.

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.

Concentration dependence ofD, T 1, andT 2 for dilute solutions of3He in solid4He

1984 ◽  
Vol 57 (1-2) ◽  
pp. 179-187 ◽  
Author(s):  
J. Schratter ◽  
A. R. Allen ◽  
M. G. Richards
Keyword(s):  
Concentration Dependence ◽  
Dilute Solutions

The absorption of sound in dilute solutions of 3 He in liquid helium II

1962 ◽  
Vol 268 (1334) ◽  
pp. 424-436 ◽  
Keyword(s):  
Liquid Helium ◽  
Sound Wave ◽  
Relaxation Times ◽  
Temperature Curve ◽  
Dilute Solutions ◽  
Helium Ii ◽  
Temperature Range ◽  
Pure Helium

The coefficient of the absorption of sound in dilute solutions of 3 He in liquid helium II has been measured in the temperature range down to 0.4 °K at a frequency of 14 Mc/s. Results are given for molar concentrations of 3 He of 0.32, 1.6 and 5.2%. In all cases the absorption is less than in pure helium II, and the peak in the absorption-temperature curve is shifted to somewhat lower temperatures. It appears that the 3 He speeds up the interactions between the thermal excitations in the liquid, and thus reduces the second viscosity which is responsible for most of the absorption in pure helium II at the higher temperatures (Khalatnikov 1950; Dransfeld, Newell & Wilks 1958). Our results are compared with a calculation of this effect due to Andreev (1961). At lower temperatures the absorption arises through a different mechanism, and a treatment taking into account the fact that all the relaxation times are long compared to the period of the sound wave has been given by Dransfeld (1958, 1962). Our results are consistent with, and give support to, Dransfeld’s treatment which involves the ‘bunching’ of the thermal phonons by the sound wave.

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