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J Depasse

Publications and source records attributed to J Depasse.

8 recordsLinked to original sources
PubMed1999

Simple Experiments to Emphasize the Main Characteristics of the Coagulation of Silica Hydrosols by Alkaline Cations: Application to the Analysis of the Model of Colic et al.

There is no consensus about the peculiar stability-coagulation behavior of silica hydrosols, in the presence of alkaline cations. Interparticle bridging or van der Waals forces prevented by steric barriers constitute the two classes of explanations. There is no agreement either on the experimental data, especially at high pH. Simple and fast experiments are proposed here, in order to clarify what must be the basis of any theory. The recent proposition of Colic et al., that involves steric barriers provided by adsorbed cations, is analyzed and shown to be unable to explain the complex behavior of silica hydrosols. Copyright 1999 Academic Press.

Journal Article↗
PubMed1997

LETTER TO THE EDITOR

Particle dehydration and interparticle binding have been advocated to explain the coagulation of silica sols by alkaline salts. Those approaches are reexamined in the light of experimental data that have recently been published. It is proposed that coagulation of silica by alkaline cations, when it occurs, is caused by interparticle hydroxo bridging. Copyright 1997 Academic Press. Copyright 1997Academic Press

Journal Article↗
PubMed1978

Interaction between silica and hydrophobic cations.

The interactions between silica and some molecules which have a high affinity for its surface have been studied. The hydrophobic properties and the positive charge of these molecules are likely to be responsible for their strong adsorption on to silica. These observations should be useful in research into new inhibitors of the effects of silica. One of the cations tested, chloroquine, has been shown to be an effective inhibitor of the haemolytic activity of quartz.

Adsorption↗