Coagulation of Colloidal Particles
| Project/Area Number |
62550706
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
化学工学
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| Research Institution | Kyushu Institute of Technology |
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Principal Investigator |
HIGASHITANI Ko Kyushu Institute of Technology, Professor, 工学部, 教授 (10039133)
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| Co-Investigator(Kenkyū-buntansha) |
KAGE Akiko Kyushu Institute of Technology, Assistant, 工学部, 助手 (60093960)
HIGASHITANI Ko Kyushu Institute of Technology, Professor (20038962)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1988: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1987: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Coagulation / Dispersion / Specific Adsorption / Floc / Coagulation Rate / 凝集速度 / 小角光散乱法 / コロイド |
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| Research Abstract |
The coagulation of colloidal particles of nm order in size was investigated; it was examined whether the stability is consistent with the so-called DLVO theory and the rate can be evaluated by the modified Smoluchowski theory. Silica particles, poly-styrene latex particles and zirconia particles of 5 nm to 200 nm in diameter were employed. A colloidal solution and an electrolyte solution (or polymer solution) were mixed by a stopped flow method, and then the change of coagulation rate was measured by a low angle light scattering apparatus. The dependences of the coagulation rate on electrolytes, particles and polymers were investigated. Following results were obtained.
1) The rapid coagulation rate constant for colloidal particles smaller than about 100 nm in diameter decreases with decreasing particle size.
2) The rapid coagulation rate constant for colloidal particles smaller than about 100 nm in diameter decreases with increasing hydration enthalpy of cations and de-creasing enthalpy of anions.
3) The rapid coagulation rate at the excessively high electrolyte concentration de-creases with the increasing concentration.
4) Flocs formed with ultrafine particles were hardly deflocculated by external forces.
5) These results imply that the stability of particles smaller than about 100 nm in diameter is not consistent with the DLVO theory and the coagulation rate can not be predicted by the Smoluchowski theory.
6) The flocculation rate of particles with polymers adsorbed on the surface in-creases with the increase of the polymer size normalized by the particle diameter.
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Report
(3 results)
Research Products
(1 results)
