Emulsion Catastrophic Inversion from Abnormal to Normal Morphology. 1. Effect of the Water-to-Oil Ratio Rate of Change on the Dynamic Inversion Frontier

Phase inversion emulsification: Current understanding and applications

“…When water is added by larger volume, the probability to create multiple emulsions is enhanced increasing addition rate, thus permitting an inversion of the phases for lower water volume fraction added. An opposite effect has been reported by Zambrano et al [100]. In this case, the higher addition rate caused a delayed but more rapid phase inversion whereas, for lower addition rate, inversion is anticipated but takes longer time scale.…”

“…If addition is slow the phase inversion can happen in smaller or larger time scales depending on the formation of multiple emulsions. For high addition rate the phase inversion seems to be delayed but happens in short time scales without displaying multiple emulsion morphology [100]. The conditions to trigger emulsion from abnormal to normal have been investigated in general [101].…”

Hydrate formation from high water content-crude oil emulsions

“…Crude oil is gradually occluded in the water drops (forming an o/W/O emulsion). The water drops swell and may reach a critical packing fraction, causing the emulsion to invert from oil to water continuous (see Sajjadi et al, 2002 andZambrano et al, 2003, for discussion of inclusion followed by catastrophic inversion). 2.…”

“…Catastrophic inversions occur much more rapidly, commonly by increasing the dispersed phase content (e.g., the inversion experiments of Hoiland et al). Multiple emulsions such as o/W/O (oil droplets within water drops dispersed in oil) or similarly w/O/W may form near the catastrophic inversion as described by Zambrano et al (2003).…”

Influence of a surfactant or salt on phase inversion in a water–oil pipe flow

“…He presents a formulation-composition map for phase inversion, which shows how the composition of the mixture at which the dispersion inverts is changing with surfactant affinity difference (SAD). Zambrano et al (2003), Mira et al (2003), Tyrode et al (2003), Sajjadi et al (2003), Tyrode et al (2005), Rondón-Gonzaléz et al (2006a,b) show how the HLD-factor (hydrophilic-lipophilic deviation from an optimum formulation), which is a less complicated concept than SAD, influences phase inversion. When HLD < 0 the surfactant exhibits a stronger affinity to oil than to water, for HLD > 0 it is the other way around.…”