1994 Fiscal Year Final Research Report Summary
Mechanism and control of adhesion and dispersion of fine particles
| Project/Area Number |
05650754
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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 |
化学工学一般
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| Research Institution | University of Osaka Prefecture |
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Principal Investigator |
KOUSAKA Yasuo Univ.of Osaka Pref., College of Engineering, Professor, 工学部, 教授 (70081346)
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| Co-Investigator(Kenkyū-buntansha) |
ENDO Yoshiyuki Univ.of Osaka Pref., College of Engineering, Research Associate, 工学部, 助手 (40233001)
NIIDA Tohru Univ.of Osaka Pref., College of Engineering, Assistant Prof., 工学部, 助教授 (60109882)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Agregate particle / Liquid bridge / Dispersion force / Adhesion force / van der Waals force |
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| Research Abstract |
Formation of aggregates difficult to disperse is considerably facilitated as the primary particle size decreases. The mechanisms of adhesion and dispersion of fine particles, which are far from being well understood, have been studied both theroretically and experimentally. The main results are breifly summarized below.
1. The mechanism of formation of liquid bridges between two different-sized spherical particles has been examined. Both the liquid bridge profiles and the adhesion force can be quantitatively predicted from the concentration of soluble impurities in the liquid, the particle diameter and the humidity.
2. In drying processes, the equilibrium moisture content of powdery materials can be controlled through adjustment of the concentration of soluble impurities.
3. The adhesion force arising from the solid salt bridge remaining after drying of the liqued bridge is a function of the original concentration of salt in liquid, the particle diameter and the surrounding humidity after drying.
4. The mechanism of dispersion of coagulated particles in water under acceleration and shear flow has also been clarified. In this case, dispersion of the agglomerated particles can be controlled by the surface potential around the particles and the pH of the suspension.
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