Measurement of Critical Disjoining Pressure for Dewetting of Solid Surfaces

✍ Scribed by Subhayu Basu; Mukul M. Sharma

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 323 KB
• Volume: 181
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1996.0401

✦ Synopsis

ing of these interaction forces is essential for describing It is shown that metastable fluid films on solid surfaces are wetting and dewetting phenomena of immiscible liquids on destabilized when the applied capillary pressure exceeds a critical solid surfaces.

disjoining pressure. This leads to a wettability reversal of the solid Surface force measurements in thin films between two substrate that can be detected using AFM measurements. Force charged solid surfaces have been well documented (1-4).

vs distance curves reveal large hysteresis when the intervening

These forces have three main components-electrostatic, liquid film is ruptured, causing wettability alteration. No hysteresis dispersion, and structural forces. The electrostatic compois observed for a stable film. A series of such experiments are nent is a result of osmotic pressure due to the excess counterconducted to investigate the effect of pH, salinity, and surface ions present in the liquid interlayer to satisfy the electroneucharacteristics on wetting behavior of solid surfaces. Quantitative measurements of disjoining pressure isotherms have been made trality condition. The dispersion component (attractive with octadecane and crude oil to better understand wettability force) results from the van der Waals interaction between alteration in oil reservoirs. These measurements also provide some the molecules of the liquid and the solid surface. The origin insight into the short-range forces of interaction between a hydroof these forces is well understood and can be quantified carbon (hydrophobic) phase and mineral (hydrophilic) surface using the classical DLVO theory (5, 6). For hydrophilic separated by aqueous electrolytes.