Coalescence coupling with flocculation in diluted emulsions with the primary and/or secondary minimum

A theoretical model is presented that allows improving the understanding of the behaviour of diluted emulsions of oil droplets in an aqueous subphase. The theory distinguishes between doublets of droplets aggregated in the primary or secondary potential minimum, called primary and secondary doublets. Only the primary doubles are subjected to a possible coalescence, while the secondary doublets can either change into primary doublets or disintegrate into singlets. The conditions for the various situations are analysed and the characteristic times evaluated. Model calculations demonstrate the influence of the key parameters on the characteristics of dilute model emulsions. The background is discussed for an experimental determination of the characteristic times for emulsions for the case of coalescence coupling with flocculation in the primary minimum, and for fragmentation coupling with aggregation in the secondary minimum.