Viscosity oily phase

Strategems to overcome some of these basic problems include (i) the use of a high viscosity oil phase in w/o/w emulsions to prevent or decrease diffusion of individual surfactant molecules and water molecules, (ii) the polymerisation of interfacially adsorbed surfactant molecules, and (iii) the gelation of the oily or aqueous phases of the emulsions. 

Take NO.2 for example. In this formulation, stearic acid, liquid paraffin and albolene serve as oily phase as well as viscosity modifier. 

The texture of an emulsion frequently reflects that of the external phase. Thus O/W emulsions usually feel watery or creamy while W/O emulsions feel oily or greasy . This distinction becomes less evident as the emulsion viscosity increases, so that a very viscous O/W emulsion may feel oily. 

Processes for the extraction of spray particles involving pressure nozzles and fluid assist spraying devices as well as different directions of mass transfer have been introduced. In a special high pressure apparatus, liquid solvents and dispersions with C02 can be extracted under high pressure. Relevant properties for the formation of drops are the viscosity of the liquid phase as well as the interfacial tension between the drop phase and the fluid phase. Results for oily and aqueous systems show a drop size distribution that is very suitable for the mass transfer. 

Oil-in-water emulsions provide a cost-effective alternative to heated pipelines or diluents for transportation of heavy crude oil or bitumen. A typical ""transport emulsion is composed of 70% crude oily 30% aqueous phase, and 500-2000 ppm of a stabilizing surfactant formulation. The resulting emulsion has a viscosity in the 50-200-cP range at pipeline operating conditions. Nonionic surfactants have the advantage of relative insensitivity to the salt content of the aqueous phase. The ethoxylated alkylphenol family of surfactants has been used successfully for the formation of stable emulsions that resist inversion. Correlations have been developed for prediction of emulsion viscosity as a function of emulsion life and process conditions. The cost of stabilizing surfactants is estimated at 0.50 to 1.00 per barrel of crude oil for a transportation distance of200 to 400 miles. 

The particle diameters of some dilute Raffo sols have been determined as 0.1-0.5 fim [31, 32]. The densities of Raffo sols increase linearly with the sulfur content and reach a value of 1.24 g cm at 16 °C for a sulfur content of 450 g [30]. After evaporation of some of the water sulfur contents of up to 600 g have been obtained Such sols are of oily or honey-like viscosity [30]. More dilute sols are clear yellow liquids stable for several weeks and undecomposed even when heated to 100 °C, provided all salts have been carefully removed. No phase transition occurs on heating up to 150 °C [30] which indicates that the sulfur and the polythionates of the sol are in a liq-uid-like state. 

Note that, whenever possible, the final step in product manufacture should be viscosity adjustment to allow for optimum mixing and for maximum energy conservation. It may be useful or necessary to dissolve the fragrance or an oily component in a small amount of concentrated surfactant prior to adding it to the aqueous phase. 

The temperature can modify the physical properties of oil, water, interfacial fUms and the solubility of surfactants in oily and aqueous phases affecting the stability of an emulsion When increasing the temperature, it is observed a decrease in viscosity of emulsion caused primarily by a decrease in oil viscosity. The temperature increases the thermal energy of drops and, consequently, increases the frequency of drop collisions. This also reduces the interfacial viscosity and results in a rate of faster drainage of the fUtn, thus increasing the coalescence of droplets. The temperature increase leads to a gradual destabilization of interfacial films. 

If possible, the densities of the oily and of the water phases should be as close as possible. Also, the viscosity of the continuous phase generally sets the viscosity of the... 

Use of High Viscosity Oii Recently Weiss et al. (2005) investigated the possibility of using a semicrystalline oil phase in W/O/gel to control the release of encapsulated hydrophilic compounds from polysaccharide gels with multiple emulsions. Various lipid phases prevent the diffusion of water/surfactant/ active material from the inner phase and also gelation of the oily or aqueous phase. For example, MCT-oil and various vegetable fats were investigated for... 

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