O/W emulsion stability

Y Sela, S Magdassi, N Garti. Release of markers from the inner water phase of W/O/W emulsions stabilized by silicone based polymeric surfactants. J Control Release 33(1) 1-12, 1995. 

Y. Sela, Y. Magdassi, and N. Garti Release of Markers from the Inner Water Phase of W/O/W Emulsions Stabilized by Silicone Based Polymeric Surfactants. J. Controlled Release 33, 1 (1995). 

Non-dairy creams (cream alternatives) are O/W emulsions stabilized by milk proteins. A relatively thick adsorption layer provides stability, mostly by steric stabilization and partly by electrostatic stabilization [829]. Figure 13.3 shows an example of a soybean-oil and milk-protein emulsion stabilized by fat globules and protein membranes. Stabilizers, such as hydrocolloid polysaccharides, are added to increase the continuous phase viscosity and reduce the extent of creaming. They must be stable enough to have a useful shelf-life but de-stabilize in a specific way when they are... 

FIGURE 8-2 Inversion of an O/W emulsion stabilized by an interfacial film of sodium cetyl sulfate and cholesterol to a W/O emulsion upon addition of polyvalent cations. Adsorption of the cations neutralizes the negative charge on the oil droplets, thus allowing them to coalesce. Reprinted with permission from J.H. Schulman and E. G. Cockbain, Trans. Faraday Soc. 36, 661 (1940). 

Taylor P. The effect of an anionic surfactant on the rheology and stability of high volume fraction O/W emulsion stabilized by PVA. Coll Polym Sci 1996 274 1061-1071. 

Dimensionless conductivity in an O/W emulsion stabilized with 2% UP366 (9300 g/mol)... 

P. Sherman, C. Parkinson, Mechanism of temperature induced phase inversion in O/W emulsions stabilized hy O/W and W/O emulsifier blends, Prog. Colloid Polym. Sci. 1978, 63, 10. 

P. Dokic, P. Sherman, Study on thermal induced phase inversion of concentrated O/W emulsions stabilized by various tween emulsifiers, Colloid Polym. Sci. 1980, 258, 1159. 

Techniques such as microscopy or the use of a Coulter counter are common techniques to study O/W emulsion stability, but they are applicable only to dilute systems. DSC represents a suitable technique to characterize a W/O emulsion without disturbing the system. Characterization of a water-in-crude oil emulsion has been studied in the laboratory. The degree of undercooling and the probable temperature obtained from a cooling thermogram allows the determination of the distribution size of dispersed droplets. By knowing the latent heat of solidification, it is also possible to determine the number of droplets crystallized at temperature T. ... 

At low temperature, over the Winsor I region, 0/W macroemulsions can be formed and are quite stable. On increasing the temperature, the O/W emulsion stability decreases and the macroemulsion finally resolves when the system reaches the Winsor III phase region (both O/W and W/O emulsions are unstable). At higher temperature, over the Winsor II region, W/O emulsions become stable. 

O/W emulsions stabilized with non-ionic surfactants tend to form W/O emulsions at elevated temperatures as the surfactant molecules dehydrate and become more lipophilic. The phase inversion temperature (PIT) can thus be ascertained by experiment. Arai and Shinoda [39] have found that the PIT of emulsions in which the oil phase consists of oil mixtures can be expressed as... 

Figure 8.25 Plots of percentage creaming or coalescence (O) and mean globule size ( ) in O/W emulsions stabilized by Brij 92-Brij 96 mixtures as a function of the HLB of the emulsifier mix at (a) 2.5 % and (b) 5 % surfactant. Results from the Coulter Nanosizer are shown (X). In the inset in (b) the details of the particle size change in the critical HLB region are shown. From [45] with permission.

W/O/W emulsions stabilized with soy lecithin-Span 80 mixtures have been used as the basis for the preparation of phospholipid vesicles [158]. A water-in-n-hexane emulsion was first prepared and the bulk of the hexane removed, the concentrate being dispersed in aqueous solution using a low concentration of hydrophilic surfactant which itself could then be removed leaving the phospholipid vesicles. 

Giizey, D., McClements, D. J. (2006). Influence of environmental stresses on o/w emulsions stabilized by b-lactoglobulin-pectin and b-lactoglobulin-pectin-chitosan membranes produced by the electrostatic layer-by-layer deposition technique. Food Biophysics, 1,30-40. 

Law TK, Florence AT, Whateley TL. 1984. Release from multiple W/O/W emulsions stabilized by interfacial complexation. J Pharm Pharmacol 36(suppl) 50. 

Figure 15.6 Optical micrographs of O/W emulsions stabilized with HMI stored at 50 °C for (a) 1.5 weeks and (b) 14 weeks.

Uses Emulsifier for cosmetics, pharmaceuticals, food applies. used in o/w emulsion stabilizers, thickeners fiber lubricant, softener in textiles PVC film antifog agent stabilizer, thickener Properties Liq. HLB 8.6 100% solids Canocol S-60 [Centro China]... 

Uses Primary o/w emulsifier, sec. o/w emulsion stabilizer, penetrant, emollient,... 

Uses Emulsifier, dispersant, solubilizer for aq. systems, o/w emulsions stabilizer for emulsions and dispersions In mtg. of foodstuffs (baked goods, margarine. Infant formulas, powd. mixes, release agents)... 

Uses Emulsifier, o/w emulsion stabilizer, and thickener for cosmetics, pharmaceuticals, and foods fiber lubricant and softener for textiles antifog Properties Liq. oil-sol. HLB 7.3 100% cone. 

Uses Emulsifier, surfactant for o/w emulsion stabilizers and thickeners used in cosmetic, agric., metalworking, leather, and textile industries vise, booster RegiMory RCRA nonreportable SARA 311/312 Immediate Health Hazard Canada DSL Europe EINECS Japan MITI Australia AICS Korea ECL Philippines PICCS China lECS... 

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