1999 Fiscal Year Final Research Report Summary
The effect of interaction between particles on flow characteristic of the clay colloidal dispersion system
| Project/Area Number |
09660252
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Irrigation, drainage and rural engineering/Rural planning
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| Research Institution | IBARAKI UNIVERSITY |
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Principal Investigator |
NAKAISHI Katsuya IBARAKI Univ. Fuc. of Agriculture, Assoc. Prof., 農学部, 助教授 (40180236)
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| Project Period (FY) |
1997 – 1999
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| Keywords | Visoelasticity / Maxwell model / Stress relaxation / Na montmorillonite / DLVO theory / Repulsive force |
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| Research Abstract |
In this study, it was quantitatively clarified that hydrodynamic interaction and viscoelastic property under steady flow depended on thickness of the diffusion double layer and intensity of the interparticle force in the dispersion region where repulsive force excels as interaction force between particles. The summary of the results is shown below.
The hydrodynamic interaction of sodium montmorillonite under dispersed condition depends only on the diffuse double layer, and interaction between clay particles becomes also stronger as the thickness of the diffuse double layer increases. This fact shows that hydrodynamic interaction is caused by the second electroviscous effect.
By analyzing the flow curve of suspension for each salt concentration using the Maxwell model, the following were quantitatively obtained : Not only newton viscosity but also elastic modulus and relaxation time of stress. As the results, it was proven that these rheology constants increased with the lowering of the s
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alt concentration. This fact indicates that repulsive force between particles influences the flow characteristic of the suspension, even when structural change of the particle is not produced.
As a result of examining orientation of the particle in the suspension state, the montmorillonite particle is arranged in parallel at 0.011 volume fraction. Therefore, it is appropriate to use the approximate formula of parallel plates due to DLVO theory in the calculation of the repulsive force.
As a result of examining the relationship between repulsive force for each salt concentration and coefficient of viscosity, elastic modulus and relaxation time, it was shown that the montmorillonite suspension was made to change to more solid property by the increase in the repulsive force. In addition, the relation between repulsive force and viscoelastic property of montmorillonite dispersed system is linear, because these rheology constants increase in proportion to the repulsive force between particles. Less
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