Water in oil droplet size

Oil in gas droplet size Oil in water droplet size Water in oil droplet size Slug volume (water slug) Inlet nozzle momentum Momentum (gas outlet) Liquid outlet velocity Operating pressure... 

A.2. An Oil-in-Water Droplet Microemulsion. Similarly, for the oil-in-water droplet-type microemulsion, the size and composition distribution of droplets is given by... 

Babick et.al. [261] compare sound spectroscopic determination of particle size distributions of sub-micron emulsions with dynamic light scattering and laser diffraction using olive oil in water droplet suspensions at volume concentrations from 1% to 60%. 

Figure 19 Double-oil diffusion experiment with nonionic surfactant, (a) Self-diffusion coefficients and (b) diffusion coefficient ratio A" as a function of temperature in a water-rich microemulsion with nonionic surfactant. A transition from oil-in-water droplets to a bicontinuous microstructure occurs with increasing temperature (decreasing spontaneous curvature of the C12E5 surfactant film). The maximum in K indicates that an attractive interaction between the micelles is operating prior to the formation of a bicontinuous structure. Kq = 1.69 is the diffusion coefficient ratio in the pure oil mixture and is indicated as a broken line in (b). Note that the initial decrease of the self-diffusion coefficients shows that the droplets grow in size before the bicontinuous transition. The phase boundary at 25.7 C is indicated as a vertical broken line. (Data from Ref 43.)...

The location of the emulsifier prior to phase inversion has been found to be of prime importance. Emulsions of smallest droplet size (less than 1 pm) is obtained when all the emulsifier is added to the alkyd before the addition of pure water. The mobility (or migration) of the surfactant during phase inversion is also decisive for the size of the oil-in-water droplets. The mobility is controlled by both the hydrophilicity (water solubility) of the surfactant and its molecular size, with a very high-molecular-weight surfactant diffusing relatively slowly... 

MoDonald P J, Ciampi E, Keddie J L, Fleidenreioh M and Kimmioh R, Magnetio resonanoe determination of the spatial dependenoe of the droplet size distribution in the oream layer of oil-in-water emulsions evidenoe for the effeots of depletion floooulation Rhys. Rev. E, submitted... 

The most important feature of o/w suspension polymerization is the formation of an oil droplet suspension of the monomer in the water and the maintenance of the individual droplets throughout the polymerization process. Droplet formation in an oil-in-water mixture is accomplished and controlled by two major factors mechanical stirring and the volume ratio of the monomer phase to water. The stirring speed is a key factor in controlling the size of oil droplets and the final size of the polymers. The stirring speed usually needs to be over... 

Photocyanations rely on photoinduced electron transfer [29]. This was demonstrated by monitoring cyanation yields as a function of the droplet size for oil-in-water emulsions. Hence increase in interfacial area is one driver for micro-channel processing. Typically, fluid systems with large specific interfacial areas tend to be difficult to separate and solutions for more facile separation are desired. 

The rates of multiphase reactions are often controlled by mass tran.sfer across the interface. An enlargement of the interfacial surface area can then speed up reactions and also affect selectivity. Formation of micelles (these are aggregates of surfactants, typically 400-800 nm in size, which can solubilize large quantities of hydrophobic substance) can lead to an enormous increase of the interfacial area, even at low concentrations. A qualitatively similar effect can be reached if microemulsions or hydrotropes are created. Microemulsions are colloidal dispersions that consist of monodisperse droplets of water-in-oil or oil-in-water, which are thermodynamically stable. Typically, droplets are 10 to 100 pm in diameter. Hydrotropes are substances like toluene/xylene/cumene sulphonic acids or their Na/K salts, glycol.s, urea, etc. These. substances are highly soluble in water and enormously increase the solubility of sparingly. soluble solutes. 

M. Heidenreich, R. Kimmich 1999, (Magnetic-resonance determination of the spatial dependence of the droplet size distribution in the cream layer of oil-in-water emulsions Evidence for the effects of depletion flocculation) Phys. Rev. E 59, 874. 

A typical characteristic of many food products is that these are multi-phase products. The arrangement of the different phases leads to a microstructure that determines the properties of the product. Mayonnaise, for example, is an emulsion of about 80% oil in water, stabilized by egg yolk protein. The size of the oil droplets determines the rheology of the mayonnaise, and hence, the mouthfeel and the consumer liking. Ice cream is a product that consists of four phases. Figure 1 shows this structure schematically. Air bubbles are dispersed in a water matrix containing sugar molecules and ice crystals. The air bubbles are stabilized by partial coalesced fat droplets. The mouthfeel of ice cream is determined by a combination of the air bubble size, the fat droplet size and the ice crystal size. 

Consider the following real life example of a process for a specific product P . This product is an oil-in-water emulsion with a droplet size of about 2pm. The emulsion is stabilized by two different emulsifiers, El and E2 . El is a so-called small emulsifier and E2 a so-called big emulsifier. The product developer specifies the levels of the oil, El and E2 and the water phase. 

Similar investigations have been carried out on water in oil microemulsions. A microemulsion is a clear, transparent, and stable system consisting of essentially monodisperse oil in water (OAV) or water in oU (W/O) droplets with diameters generally in the range of 10-200 nm. Microemulsions are transparent because of their small particle size, they are spherical aggregates of oil or water dispersed in the other liquid, and they are stabilized by an interfacial film of one or more surfactants. 

The term microemulsion is applied in a wide sense to different types of liquid liquid systems. In this chapter, it refers to a liquid-liquid dispersion of droplets in the size range of about 10-200 nm that is both thermodynamically stable and optically isotropic. Thus, despite being two phase systems, microemulsions look like single phases to the naked eye. There are two types of microemulsions oil in water (O/W) and water in oil (W/O). The simplest system consists of oil, water, and an amphiphilic component that aggregates in either phase, or in both, entrapping the other phase to form... 

J. Floury, A. Desrumaux, and J. Lardieres Effect of High-Pressure Homogenization on Droplet Size Distributions and Rheological Properties of Model Oil-in-Water Emulsions. hmovat. Food Sci. Emergi. Technol. 1, 127 (2000). 

The size of the micelles is significantly increased by the addition of monomer up to a diameter of 4.5-5 nm. However, the size of the monomer droplets is stilt very much larger than that of the micelles (diameters up to 1 pm). In emulsion polymerization, one generally uses 0.5-5 wt% of emulsifier relative to monomer. With the usual oil-in-water emulsions, the water content varies from half to four times the amount of monomer. 

The objective of this paper is to illustrate the efficacy of inferring the interdroplet forces in a concentrated protein stabilized oil-in-water emulsion from the knowledge of the equilibrium profile of continuous phase liquid holdup (or, dispersed phase faction) when the emulsion is subjected to a centrifugal force field. This is accomplished by demonstrating the sensitivity of continuous phase liquid holdup profile for concentrated oil-in-water emulsions of different interdroplet forces. A Mef discussion of the structure of concentrated oil-in-water emulsion is presented in the next section. A model for centrifugal stability of concentrated emulsion is presented in the subsequent section. This is followed by the simulation of continuous phase liquid holdup profiles for concentrated oil-in-water emulsions for different centrifugal accelerations, protein concentrations, droplet sizes, pH, ionic strengths and the nature of protein-solvent interactions. 

Centrifugal stability of protein-stabilized concentrated oil-in-water emulsions, 229-245 centrifugal acceleration, 237,238/ droplet size, 240,241/ film thickness vs. emulsion height, 237,239/240 ionic strength, 240,245/ model, 232-237 X parameters, 240,243/... 

Table 7.1 Effect of xanthan (XG) and NaCl on oil-in-water emulsions (50 vol% com oil) made at pH = 7.0 with legume seed protein isolate (LSPI) as emulsifying agent total protein adsorbed (Tt), average droplet size c/32, and amount of LSPI adsorbed per unit area of surface (Ts). Data from Makri et al. (2005) with permission.

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