Dissipation of Film Drainage Resistance by Hydrophobic Surfaces in Aqueous Solutions

Understanding and minimizing the film drainage resistance (forces) from a moving fluid are of great importance both scientifically and technologically. The direct and accurate measurement of film drainage resistance was made possible by integrating a speaker diaphragm of large displacement range and rapid responses with a sensitive bimorph force sensor and high resolution digital camera. Our study demonstrates that the liquid film drainage resistance can be greatly diminished or accurately controlled by increasing or controlling the hydrophobicity of solid surfaces. The results show that for a given solid surface hydrophobicity, the film drainage resistance at the point where film ruptures increases linearly with increasing bubble approach velocity. The dependence of the film drainage resistance on bubble approach velocity decreases linearly with increasing hydrophobicity of the solid surface. This finding has important implications for biological processes, microfluidic devices, and design of new materials

Dissipation of Film Drainage Resistance by Hydrophobic Surfaces in Aqueous Solutions

Understanding and minimizing the film drainage resistance (forces) from a moving fluid are of great importance both scientifically and technologically. The direct and accurate measurement of film drainage resistance was made possible by integrating a speaker diaphragm of large displacement range and rapid responses with a sensitive bimorph force sensor and high resolution digital camera. Our study demonstrates that the liquid film drainage resistance can be greatly diminished or accurately controlled by increasing or controlling the hydrophobicity of solid surfaces. The results show that for a given solid surface hydrophobicity, the film drainage resistance at the point where film ruptures increases linearly with increasing bubble approach velocity. The dependence of the film drainage resistance on bubble approach velocity decreases linearly with increasing hydrophobicity of the solid surface. This finding has important implications for biological processes, microfluidic devices, and design of new materials