Stability of emulsions of water in oil

Albers, Willem M.; Overbeek, J. Th. G.

doi:10.1016/0095-8522(59)90016-9

Cited by 73 publications

(51 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, the notion that a high colloid surface-potential (and consequently a large particle charge) at low colloid concentrations does not necessarily guarantee stability has been proposed for some time. Over fifty years ago, Albers and Overbeek 23,24 noted the absence of any correlation between the electrokinetic ζ-potential of water-in-benzene emulsions and their stability against coalescence. Later work by Mishchuk, Sanfeld, and Steinchen 25 suggested that a charge-stabilized water-in-oil emulsion should be unstable above a critical volume fraction, which reduced as the ion concentration fell.…”

Section: Introductionmentioning

confidence: 99%

Charge regulation of nonpolar colloids

et al. 2018

View full text Add to dashboard Cite

Individual colloids often carry a charge as a result of the dissociation (or adsorption) of weakly-ionized surface groups. The magnitude depends on the precise chemical environment surrounding a particle, which in a concentrated dispersion is a function of the colloid packing fraction η. Theoretical studies have suggested that the effective charge Z eff in regulated systems could, in general, decrease with increasing η. We test this hypothesis for nonpolar dispersions by determining Z eff (η) over a wide range of packing fractions (10 −5 ≤ η ≤ 0.3) using a combination of small-angle X-ray scattering and electrophoretic mobility measurements. All dispersions remain entirely in the fluid phase regime. We find a complex dependence of the particle charge as a function of the packing fraction, with Z eff initially decreasing at low concentrations before finally increasing at high η. We attribute the non-monotonic density dependence to a crossover from concentrationindependent screening at low η, to a high packing fraction regime in which counterions outnumber salt ions and electrostatic screening becomes η-dependent. The efficiency of charge stabilization at high concentrations may explain the unusually high stability of concentrated nanoparticle dispersions which has been reported 1 .

show abstract

Section: Introductionmentioning

confidence: 99%

Charge regulation of nonpolar colloids

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Double layer repulsions will in principle promote further redispersion and if left out of account simulate too low a van der Waals' constant. Quantitative calculations as given in parts I and II of this series (1,3) prove that the force of the double layer repulsion is only a small fraction of that of the van der Waals' attraction and could never explain that the van der Waals' constant is one to two orders of magnitude smaller than expected.…”

Section: The Van De~ Waals' Constantmentioning

confidence: 99%

“…In general W/O emulsions containing droplets with a radius ~ 1/~ will therefore be either broken or flocculated, depending on their stability against coalescence (1,3). If they are not stabilized against coalescence, they will flocculate and break.…”

Section: Charged Dropletsmentioning

confidence: 99%

See 1 more Smart Citation

Stability of emulsions of water in oil III. Flocculation and redispersion of water droplets covered by amphipolar monolayers

Albers

Overbeek

1960

Journal of Colloid Science

Self Cite

View full text Add to dashboard Cite

Theoretical calculations demonstrate that emulsions of water in oil cannot be sufficiently protected against flocculation by an adsorbed layer of amphipolar molecules with an oleophilic chain of about 20 A. It is, however, expected that such flocculated emulsions can be redispersed by moderate rates of shear. This is confirmed by viscosity measurements. Non-Newtonian behavior found at low rates of shear is a consequence of fioeculation. From the minimum rate of shear to reach the Newtonian region, i.e., to cause complete redispersion, the effective van der Waals' constant between the water droplets can be estimated. The rather low value of A = 0.4 X 10 -14 erg is found.

show abstract

“…The filter bed, through which the emulsion is filtered, may be made of an excelsior, [2], clean sand [3], fossil flour, clay or marble [4], Fe 2 O 3 or amphibole [5], porous mass of crushed Al 2 O 3 [6], a layer of silica, pyrites and other [7][8][9][10][11][12][13][14][15][16] …”

Section: Introductionmentioning

confidence: 99%

Studying breaking of inverted emulsions with thermolysis purification TD₆₀₀

Тарасова

Shevaga

Grachyova

2018

IOP Conf. Ser.: Mater. Sci. Eng.

View full text Add to dashboard Cite

Currently, emulsions are used in many branches of industry and agriculture. It explains significant attention paid to issues in production, stabilization and breaking of emulsion. Besides, producing steady emulsions is of importance in many processes; the reverse problem, that of demulsification, is important as well in oil production and treatment of oil emulsion waste water. This paper studies the breaking (demulsification) of inverted emulsions with the help of thermolysis purification TD 600 , produced by thermal modification of purification, a large-scale waste of the sugar industry.

show abstract

Stability of emulsions of water in oil

Cited by 73 publications

References 2 publications

Charge regulation of nonpolar colloids

Charge regulation of nonpolar colloids

Stability of emulsions of water in oil III. Flocculation and redispersion of water droplets covered by amphipolar monolayers

Studying breaking of inverted emulsions with thermolysis purification TD₆₀₀

Contact Info

Product

Resources

About

Stability of emulsions of water in oil

Cited by 73 publications

References 2 publications

Charge regulation of nonpolar colloids

Charge regulation of nonpolar colloids

Stability of emulsions of water in oil III. Flocculation and redispersion of water droplets covered by amphipolar monolayers

Studying breaking of inverted emulsions with thermolysis purification TD600

Contact Info

Product

Resources

About

Studying breaking of inverted emulsions with thermolysis purification TD₆₀₀