Surface and interfacial tensions of aqueous dispersions of charged colloidal (clay) particles

Abstract

Can. J. Chem. 72, 1915 (1994. We have measured (du Nouy ring and maximum bubble pressure methods) suspension-air surface tensions of aqueous suspensions of montmorillonite and have observed that these surface tensions are larger than those of pure water at the same temperatures. Further measurements have shown that dispersed montmorillonite also increases the suspension-toluene interfacial tension compared with that of pure water-toluene. Similar measurements on aqueous suspensions of kaolinite have yielded suspension-air interfacial tensions with uncertainties as large as the observed (small) effect, and also shown that the suspension--toluene interfacial tension is decreased (opposite to the effect of montmorillonite) by amounts larger than the experimental uncertainties. Measurements of maximum bubble pressures at different flow rates have provided information about the effect of surface age on observed surface tensions. LAURER L. SCHRAMM et LOREN G. HEPLER. Can. J. Chem. 72, 1915Chem. 72, (1994. On a mesurt (par les methodes du cercle de Nouy et de la pression maximale de la bulle) les tensions de surface suspensionlair de suspensions aqueuses de montmorillonite et on a observk que, aux mbmes tempkratures, ces tensions de surface sont plus importantes que celle de I'eau pure. Des mesures additionnelles ont permis de montrer que la montmorillonite disperste augmente aussi la tension interfaciale de la suspension/tolu&ne par rapport B celle de l'eau pureltolubne. Des mesures semblables sur des suspensions aqueuses de kaolinite ont fourni des tensions interfaciales suspensionlair pour lesquelles les incertitudes sont aussi importantes que le (faible) observe et on aussi permis de dtmontrer que la tension interfaciale suspensionltolubne diminue (effet oppost B celui de la montmorillonite) par des quantitts plus importantes que les incertitudes exptrimentales. Des mesures par la mtthode des pressions maximales de la bullel B diverses vitesses d'tcoulement ont fourni de I'information concernant I'effet de I'age de la surface sur les tensions de surface observtes.[Traduit par la rtdaction]

Formation and Control of Self-Sealing High Permeability Groundwater Mounds in Impermeable Sediment: Implications for SUDS and Sustainable Pressure Mound Management

“…The wetting angle between water and mineral matter is small and cos θ may be approximated as 1.0 [14]. Low concentrations of flocculated, or suspended, or colloidal clay, or surfactant, in an advancing water front can reduce θ [31,32]. P M represents a critical switch, which can abruptly increase, or decrease, the flow rate through a sediment by many orders of magnitude [3,4], by adjusting the sediments intrinsic permeability (Equation 4) when the driving force, P, (e.g., water depth in the infiltration device) falls below P M .…”

Morphological instability of a non-equilibrium ice–colloid interface

“…Not much is known about the concentration dependence of γ , though limited experimental evidence indicates that the dependence is weak, or at least bounded as the concentration increases (Schramm & Helper 1994;Dong & Johnson 2004). In the following, we take γ to be a constant.…”

Effect of charged colloidal particles on adsorption of surfactants at oil–water interface

“…The effect of solids, alone or in combination with ionic chemical species, on the interfacial tension remains an open question. Schramm and Hepler [1] reported that adding montmorillonite clay into the water phase increased the interfacial tension of toluene in contact with water, while adding kaolinite clay lowered the interfacial tension of the two liquids. Brian and Chen [2] had a different view.…”