Coagulation of Colloidal Silica by Alkaline Cations: Surface Dehydration or Interparticle Bridging?
✍ Scribed by J. Depasse
- Publisher
- Elsevier Science
- Year
- 1997
- Tongue
- English
- Weight
- 76 KB
- Volume
- 194
- Category
- Article
- ISSN
- 0021-9797
No coin nor oath required. For personal study only.
✦ Synopsis
studies of Bell and Prue (14), Gimblett and Monk concluded that Li / and Na / associate with hydroxide ions, whereas KOH, RbOH, and CsOH are Particle dehydration and interparticle binding have been advocompletely dissociated (15). The dissociation constants at 25ЊC lie between cated to explain the coagulation of silica sols by alkaline salts. 0.65 and 0.67 for LiOH and between 3.7 and 5.9 for NaOH. Li / and Na / , Those approaches are reexamined in the light of experimental data but not the other alkaline cations, therefore have an acidic character. that have recently been published. It is proposed that coagulation Robinson and Harned suggested that the alkaline cations interact with of silica by alkaline cations, when it occurs, is caused by interpartihydroxide ions through a water molecule, following a localized hydrolysis cle hydroxo bridging. ᭧ 1997 Academic Press mechanism (16). With those data in mind, Depasse and Watillon proposed