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Coagulation of Colloidal Particles

胶体颗粒的凝结

基本信息

批准号：
62550706
负责人：
HIGASHITANI Ko
金额：
$ 1.15万
依托单位：
Kyushu Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-62550706/
关键词：
Coagulation Dispersion Specific Adsorption Floc Coagulation Rate 凝集速度小角光散乱法コロイド

项目摘要

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.

研究了纳米级胶体颗粒的混凝作用；考察了其稳定性是否符合所谓的DLVO理论，并且可以用修正的Smoluchowski理论来评价其速率。采用直径为5 ~ 200 nm的二氧化硅颗粒、聚苯乙烯乳胶颗粒和氧化锆颗粒。采用停流法将胶体溶液与电解质溶液（或聚合物溶液）混合，然后用低角光散射仪测量混凝率的变化。研究了混凝速率与电解质、颗粒和聚合物的关系。得到以下结果：1)粒径小于100 nm的胶体颗粒的快速凝聚速率常数随粒径的减小而减小。2)粒径小于100nm的胶体颗粒的快速混凝速率常数随着阳离子水化焓的增大和阴离子水化焓的减小而减小。3)电解质浓度过高时的快速凝血速率随浓度的增加而降低。4)超细颗粒形成的絮凝体在外力作用下几乎不发生脱絮。5)这些结果表明直径小于100 nm的颗粒的稳定性与DLVO理论不一致，并且不能用Smoluchowski理论来预测凝固速率。6)表面吸附聚合物的颗粒絮凝率随着粒径归一化后聚合物粒径的增大而增大。