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

Piela, K.; Djojorahardjo, E.; Koper, Ger J. M.; Ooms, G.

doi:10.1016/j.cherd.2009.04.009

Cited by 8 publications

(4 citation statements)

References 24 publications

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“…On the contrary, the intermediate phase has a morphology rich of multiple droplets and "pockets" containing droplets, with an evolution towards the inverted isolated droplet morphology induced mainly by coalescence, break-up and escaping phenomena. They also stated in a later work [175] that the creation of such morphology, i.e., multiple emulsions of oil in water in oil droplets (the so called "pockets") along with a dispersion of clean oil drops in water is due to the presence of surface active substance already present in the liquids, with an affinity towards oil rather than water. During the continuous experiment they showed that the critical volume fraction of the dispersed phase (the volume fraction to achieve inversion) is not dependent on Reynolds number, Froude number, Weber number and on the dispersed phase injection velocity as long as the latter is sufficiently large (2 m/s) [147,173,175].…”

Section: Tube Flowmentioning

confidence: 94%

“…Piela et al [173] also showed that the ambivalence region is unique for a specific water-oil mixture. Their final statement is that phase inversion critical volume fraction is dependent only on the injected phase volume fraction and that the effect of surfactant [175] is only to shift the ambivalent range and does not alter the linear relationship between critical volume fraction and injected phase volume fraction. It has to be noted that the surfactant used by Piela et al was at low concentration, nearby CMC; it is not clear whether larger surfactant concentrations could have an impact on the ambivalent region.…”

Section: Tube Flowmentioning

confidence: 99%

See 1 more Smart Citation

Phase inversion emulsification: Current understanding and applications

Perazzo

Preziosi

Guido

2015

Advances in Colloid and Interface Science

209

121

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Section: Tube Flowmentioning

confidence: 94%

Section: Tube Flowmentioning

confidence: 99%

Phase inversion emulsification: Current understanding and applications

Perazzo

Preziosi

Guido

2015

Advances in Colloid and Interface Science

209

121

View full text Add to dashboard Cite

“…Although numerous studies already address the scarcity of experimental and theoretical publications over the decades, recent developments and a surge in interest have led to numerous studies exploring the effects of various properties including viscosity and operational conditions, electrolytes, and of particular interest, surfactants, and their role in influencing phase inversion.…”

Section: Current State Of Researchmentioning

confidence: 99%

Cross Linking Between the Baffling Effect and Phase Inversion During Liquid–Liquid Monomer Mixing

Cocke

Maaß

2017

Macro Reaction Engineering

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remains one of the most difficult and least understood mixing problems, in contempt of its major significance for optimization of suspension polymerization. The first step of the process, the liquid-liquid mixing and even more the medium conversion stage with increased dispersed phase viscosity and sticky polymer-monomer particles already determines the size of the final particle size distribution.Xie et al. are introducing this major challenge and give a meaningful introduction about suspension polymerization. [1] It has been widely used to produce poly-(vinyl chloride), poly-(vinylidene chloride) copolymers, polystyrene, poly-(methyl methacrylate), and high value-added polymer particulate products (e.g., chromatographic separation media, ion exchange resins, and enzyme immobilization supports). During the suspension polymerization process, a monomer (or monomers) that is immiscible or slightly soluble in water is first dispersed to form monomer droplets by stirring in the aqueous phase containing a dispersant-the liquid-liquid mixing process.Recent studies have revealed unexpected developments in drop size by only small changes in the geometrical constraints of batch vessels used for suspension polymerization. The effect of the dispersed phase fraction, surfactant concentration, as well as baffle length on the evolving drop size distribution in different low viscous liquid-liquid systems is investigated. The analysis is focused on the drop-dominated systems by hindering the coalescence by polyvinyl alcohol (PVA) concentrations up to three times higher than the critical micelle concentration. The influence of PVA on drop size in breakage-dominated systems is well reproduced with population balance equation simulations. The drops are measured using a photo-optical system with automated image analysis. The measured drop sizes increase with increasing dispersed phase fraction. As coalescence is completely hindered, all observed coalescence effects are connected to phase inversion, a catastrophic phenomenon during suspension polymerization for industrial production processes. Phase inversion can be reproduced for all studied solvents with and without the use of surfactants. In particular, the influence of the baffles can be reproduced. The system is adapted and trained to detect phase inversion as a warning system to make the suspension polymerization process more stable and robust.

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“…It is also influenced by the method and extent of energy input during emulsification and, under some circumstances, the mechanism is thought to involve the formation of multiple emulsions (oil-in-water-in oil or water-in-oil-in-water). The behavior of surfactant-containing systems prepared by standard emulsification methods is detailed in refs − ; studies of systems (with or without surfactants) in turbulent flow in pipes are described in refs − .…”

Section: Introductionmentioning

confidence: 99%

High Internal Phase Emulsions: Catastrophic Phase Inversion, Stability, and Triggered Destabilization

2011

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We have investigated the formation, drop sizes, and stability of emulsions prepared by hand shaking in a closed vessel in which the emulsion is in contact with a single type of surface during its formation. The emulsions undergo catastrophic phase inversion from oil-in-water (o/w) to water-in-oil (w/o) as the oil volume fraction is increased. We find that the oil volume fraction required for catastrophic inversion exhibits a linear correlation with the oil-water-solid surface contact angle. W/o high internal phase emulsions (HIPEs) prepared in this way contain water drops of diameters in the range 10-100 μm; emulsion drop size depends on the surfactant concentration and method of preparation. W/o HIPEs with large water drops show water separation but w/o HIPEs with small water drops are stable with respect to water separation for more than 100 days. The destabilization of the w/o HIPEs can be triggered by either evaporation of the oil continuous phase or by contact the emulsion with a solid surface of the "wrong" wettability.

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

Cited by 8 publications

References 24 publications

Phase inversion emulsification: Current understanding and applications

Phase inversion emulsification: Current understanding and applications

Cross Linking Between the Baffling Effect and Phase Inversion During Liquid–Liquid Monomer Mixing

High Internal Phase Emulsions: Catastrophic Phase Inversion, Stability, and Triggered Destabilization

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