초록 |
Antifoam formulations for use on aqueous foams are hydrophobic solid particles, nonpolar oil with very low solubility in the aqueous phase, or mixtures of insoluble nonpolar oil and hydrophobic solid particles. It is widely accepted that the main role of the hydrophobic solid particles is known to destabilize the oil-water-air film, and thus facilitating drop entry. After entry, the subsequent oil spreading along the lamellae surface or bridging and dewetting then leads to a rapid rupture of a film. Central to the effect of oils is whether or not small oil drops dispersed within an aqueous surfactant solution will enter the air-water surface. In this study, foam stability with oils and solids consisting of fatty materials such as liquid triglycerides and/or long-chain fatty acids was investigated and the result was analyzed using a time-dependent ESB(entry, spreading and bridging coefficients) analysis. Of particular interest was the effect on foam stability of time-dependent processes such as calcium soaps of these fatty acids and/or calcium carbonate. |