| Autor: |
Shchukin, E.D., Amelina, E.A., Yaminsky, V.V. |
| Zdroj: |
Colloids and Surfaces; April 1981, Vol. 2 Issue: 3 p221-242, 22p |
| Abstrakt: |
The adhesion forces between two hydrophobic (methylated glass) and two hydrophilic (non-modified glass) spherical particles about 1 mm in diameter were directly measured in a variety of liquid media including surfactant solutions. The areal free energies of adhesion 12Fcorresponding to the depth of the primary (short-distance) potential energy minimum are calculated by means of Deryaguin's adhesion theory. Depending on the nature of the solid surfaces and the environment, 12Franges over a broad spectrum from 10−2to 10+2mJ m−2. The difference Δ12Fbetween 12Fin air and in a liquid is shown to be Δσ, the difference between interfacial tnesions at the particle/air and particle/liquid interfaces, provided immediate contact between the solid surfaces in the liquid form. The contribution of dispersion and non-dispersion forces to the adhesion of particles in liquid media is discussed in terms of Fowkes's model. The results on adhesion are compared with the data on stability of non-polar powder suspensions. The Rehbinder-Shchukin criterion of spontaneous dispersion is applied to the process of peptization and its implications in the thermodynamics of colloid stability are discussed. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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