Emulsifier concentrations, effect emulsion systems

Quasi-elastic light scattering is an excellent technique for studying the formation and stability of submicrometer emulsions. Improvements in the methods of quasi-elastic light scattering data acquisition and analysis that enable full particle-size distribution studies of sub-micrometer emulsion systems are discussed. Using several oil/water emulsion systems as examples, we demonstrate the ability of these techniques to determine the effect of emulsifier concentration on the particle-size distribution produced by an inversion method of emulsification. Some of the benefits of obtaining the full distribution are also discussed. 

Blends of different organosiloxanes, i.e., hydrophobic together with somewhat hydrophobic siloxanes, have also been claimed [71]. These blends can be used to produce highly concentrated antifoam emulsions that can be easily diluted. The stability of these systems can qualitatively be understood in view of the 3D-HLB system. The hydrophilic siloxane acts as an ideal emulsifying component for the hydrophobic siloxane, though synergistic effects between both components may be also observed. 

Perhaps the most interesting findings experimentally have arisen from investigating the effect of surfactant concentration on emulsion stability. Various surfactants, when present at a critical concentration above their CMC, cause emulsions to flocculate leading to rapid creaming/sedimentation. The presence therefore of free (i.e. not emulsified) surfactant is implicated in this process. The systems include 0/W emulsions stabilised by either nonionic " or ionic surfactants, " "" and flocculated by aqueous micelles, vesicles " or water-soluble... 

Whey protein concentrates (WPC), which are relatively new forms of milk protein products available for emulsification uses, have also been studied (4,28,29). WPC products prepared by gel filtration, ultrafiltration, metaphosphate precipitation and carboxymethyl cellulose precipitation all exhibited inferior emulsification properties compared to caseinate, both in model systems and in a simulated whipped topping formulation (2. However, additional work is proceeding on this topic and it is expected that WPC will be found to be capable of providing reasonable functionality in the emulsification area, especially if proper processing conditions are followed to minimize protein denaturation during their production. Such adverse effects on the functionality of WPC are undoubtedly due to their Irreversible interaction during heating processes which impair their ability to dissociate and unfold at the emulsion interface in order to function as an emulsifier (22). 

The C12-(EO)9-MA macromonomer was found to be a very effective emulsifier for BzMA in water even at a concentration less than 5 wt%, to give a stable milky emulsion [42,96]. Table 3 shows that the rate of polymerization depends on the initiator type and polarity of continuous phase. In water solution, the rates are several times higher than in heptane. The rate of polymerization increases with increasing macromonomer concentration in systems with KPS and AIBN, and it is constant with AVA. The higher the macromonomer concentration, the higher the particle concentration and rate of polymerization. These results indicate that distribution of the initiator between the phases influences in complex way the polymerization and nucleation mechanism. 

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