The self bodying action of the mixed emulsifier sodium dodecyl sulfate/cetyl alcohol

Rapid Evaluation of Water-in-Oil (w/o) Emulsion Stability by Turbidity Ratio Measurements

“…The emulsion-breaking processes have been studied extensively by many investigators and various methods of determining the emulsion stability have been proposed such as droplet size analyses (1), measuring physical properties of emulsion (2), accelerated tests (3,4), and light-scattering (5). Among these methods, the most common is droplet size analysis and microscopy, which is tedious and time-consuming.…”

“…Turbidity measurements were also used to determine emulsion stability (6), and a technique utilizing the spectral absorbance at several wavelengths was proposed to allow the determination within a relatively short period of time (7). Since the turbidity of a polydispersion is the sum of all the contributions over the various particle sizes, the turbidity (τ ) of the total distribution and the volume fraction (φ) expressed in integral form are [2] where N is the particle concentration, r is the radius of particle, λ is wavelength in the dispersing medium, α (=2πr/λ) is the dimensionless particle size, f (α) is the number fraction of particles with a size between α and α + dα, Q is the scattering coefficient, and m is the ratio of the refractive index of particles to the refractive index of medium (8). Since the volume fraction is either known only approximately or not at all, it can be eliminated by taking a ratio of turbidities at two widely separated wavelengths.…”

Rheology of systems containing cetrimide-cetostearyl alcohol: variation with temperature

“…The self bodying action of the mixed emulsifiers sodium dodecyl sulphate-cetyl alcohol and of cetrimide-cetostearyl alcohol has been studied (Barry, 1968;Barry & Saunders, 1970). In these emulsions the gel structure responsible for the self bodying phenomenon consists of frozen smectic phase with similar properties to an oil-free ternary system formed by dispersing cetrimide and cetostearyl alcohol in water.…”

Structure and rheology of emulsions stabilised by mixed emulsifiers

“…Liquid paraffin in water emulsions stabilised by the mixed emulsifier sodium dodecyl sulphate/cetyl alcohol can be examined in a similar manner (29). The flow curves are hysteresis loops but spur points are either absent or much less prominent.…”

“…For the mixed emulsifier sodium dodccyl sulphate/ cetyl alcohol, increasing the concentration from approximately 2-10% causes each viscosity to rise sharply as the gel network forms and then to level off. Compliance J1 and viscosity */1, of Voigt unit 1 versus approximate emulsifier concentration for liquid paraffin in water emulsions stabilised by the mixed emulsifier sodium dodecyl sulphate/eetyl alcohol (after Barry,29) mide/cetostearyl alcohol emulsions and at high concentrations there are further increases in the viscosity values and decreases in the compliances. Fig.…”