科研之友
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摘要
Colloid probe atomic force microscopy experiments were carried out between a titania particle and an air bubble in KCl solutions. The surface charges of both the bubble and the particle were controlled by varying the electrolyte concentration and pH of the solution. In all experiments, the bubbles were negatively charged while the titania particles were either negatively (above the pH of the point of zero charge, pH(PZC)) or positively (below pH(PZC)) charged. The experimental results have been compared with a theoretical model of the thin-film drainage to investigate the effect of repulsive van der Waals interactions and attractive double layer interactions in promoting hysteresis and hydrodynamic pull-off forces in dynamic particle bubble interactions. This is the first such system we are aware of that has been analyzed at this level of detail: most of the previous studies have dealt with stable films under a repulsive disjoining pressure or unstable films under an attractive disjoining pressure. The outcomes of this study are important in fields as diverse as water treatment, mineral flotation, and biology.
- 出版日期2011-6-9
