Emulsification involved

The cleaning process proceeds by one of three primary mechanisms solubilization, emulsification, and roll-up [229]. In solubilization the oily phase partitions into surfactant micelles that desorb from the solid surface and diffuse into the bulk. As mentioned above, there is a body of theoretical work on solubilization [146, 147] and numerous experimental studies by a variety of spectroscopic techniques [143-145,230]. Emulsification involves the formation and removal of an emulsion at the oil-water interface the removal step may involve hydrodynamic as well as surface chemical forces. Emulsion formation is covered in Chapter XIV. In roll-up the surfactant reduces the contact angle of the liquid soil or the surface free energy of a solid particle aiding its detachment and subsequent removal by hydrodynamic forces. Adam and Stevenson s beautiful photographs illustrate roll-up of lanoline on wood fibers [231]. In order to achieve roll-up, one requires the surface free energies for soil detachment illustrated in Fig. XIII-14 to obey... 

Emulsification involves the joining of two mutually insoluble materials, such as petroleum oil and water. The surfactant, which usually has a hydrophilic or water-soluble end and a hydrophobic or oil-soluble end, holds the oil and water together in much the same manner that a fastener holds two pieces of material. Often, the emulsion which forms is unstable, subsequently breaking up and releasing the oil from the water. Break-up is actually preferred, because the oil then floats to the surface, whereas the surfactant is free to emulsify more oil. 

A comparison of the curves of Figure 7 with those of Figures 4 and 5 clearly shows that the solubility and the emulsifying capacity are not correlated. The optimal conditions for emulsification seem to be at a DH-value where the hydrolysate consists of approximately equal amounts of soluble and insoluble material. Emulsification involves both hydrophilic and hydrophobic groups in the same molecules and it is therefore important that the molecules are not too small. Also, film formation and surface de-naturation play a role, and this also implies that the molecules should not be too small. On the other hand, a certain solubility seems to be necessary for achieving the maximum emulsifying capacity. 

De-emulsiftcation one of the stumbhng blocks in the construction of a continuous liquid membrane process plant is de-emulsification and recovery of the solvent. De-emulsification involves coalescence of dispersed droplets into larger droplets with subsequent phase separation by gravity. The most popular method to augment this process is by apphcation of an electric field. This indicates that hquid membrane plants will be energy intensive. 

In this technique, a transition in the affinity is obtained by changing the water volume fraction, instead of changing the temperature. By successively adding water into oil, initially water droplets are formed in a continuous oil phase. Increasing the water volume fraction changes the spontaneous curvature of the surfactant from initially stabilizing a w/o microemulsion to an o/w microemulsion at the inversion locus. This transition is referred to as PIC. PIC method of emulsification involves... 

Aluminum salts (e.g. nitrate) have proved to be a popular source for the synthesis of alumina particles through macroemulsions, as clearly shown from the above examples. However, there are other examples where aluminum alkoxides are used for the same purpose. In one example provided by Hardy etai [177], the procedure of emulsification involved ultrasonication of the alkoxide in immiscible, non-reacti ve, polar organic liquids prior to contact with water for direct conversion of the alkoxide droplets to solid particles. Thus, aluminum secondary butoxide dispersed in acetonitrile or propylene carbonate was hydrolyzed by addition of water [ 177] to obtain generally near-spherical particles of alumina varying in size from several microns to several nanometers. These particles, amorphous without calcination, changed to y-alumina of high surface area on calcination at 6(X) C and 0-alumina at IGOO C. 

The emulsion blocking mechanism involves formation of emulsion in the pores either by self-emulsification of water-based filtrate with the crude oil, or oil filtrate from an oil-based fluid emulsifying formation water. The emulsions are viscous and can block the pores. The remedial design is to prevent emulsification either by eliminating oil from completion fluid or by the use of demulsifiers. 

Microcapsules of PCL and its copolymers may be prepared by aircoating (fluidized bed), mechanical, and, most commonly, solution methods. Typically, the solution method has involved emulsification of the polymer and drug in a two-phase solvent-nonsolvent mixture (e.g., CH2Cl2/water) in the presence of a surfactant such as polyvinyl alcohol. Residual solvent is removed from the tnicrocapsules by evaporation or by extraction (70). Alternatively, the solvent combination can be miscible provided one of the solvents is high-boiling (e.g., mineral spirits) phase separation is then achieved by evaporation of the volatile solvent (71). The products of solution methods should more accurately be called microspheres, for they... 

Different methods are used in microemulsion formation a low-energy emulsification method by dilution of an oil surfactant mixture with water and dilution of a water-surfactant mixture with oil and mixing all the components together in the final composition. These methods involve the spontaneous formation of microemulsions and the order of ingredient addition may determine the formation of the microemulsion. Such applications have been performed with lutein and lutein esters. ... 

In interfacial polymerization, monomers react at the interface of two immiscible liquid phases to produce a film that encapsulates the dispersed phase. The process involves an initial emulsification step in which an aqueous phase, containing a reactive monomer and a core material, is dispersed in a nonaqueous continuous phase. This is then followed by the addition of a second monomer to the continuous phase. Monomers in the two phases then diffuse and polymerize at the interface to form a thin film. The degree of polymerization depends on the concentration of monomers, the temperature of the system, and the composition of the liquid phases. 

The physical methods include dilution, emulsification, addition of surface active agents, etc. Chemical conversion includes those methods involving carbon rejection and those of hydrogen addition . So far, there has not been any bioconversion process that has accomplished the developmental stage however, there have been some MEOR initiatives, which could be taken as inspiration for upgrading routes. Some of them will be mentioned here as examples, but will be specifically identified as MEOR alternatives. 

In the second animal experiment, involving albino rabbits, the clinical tolerance of Oxane Hd appeared to be good with no inflammatory reaction and no retinal vascular lesion. No emulsification was noted. Optical microscopy of semi-thin layers elicited only a few retinal lesions atrophy of the retinal external layers was observed in one eye treated with the mixture and one treated with standard silicone oil. We found a few rare cells in the vitreous cavity, which contained intra-cytoplasmic vacuoles. Electron microscopy confirmed the absence of damage to the pigmentary epithelium and to the retinal internal layers and atrophy of the retinal external layers in two cases treated with the mixture and in one case treated with standard silicone oil (Fig. 2). 

No generalities seem justified regarding the relationship between concentration of emulsifier and oil deposit obtained. An increase in the concentration of certain emulsifiers has been found to increase the oil deposit, while in other cases the reverse has been true. It is clear that both the individual characteristics of the emulsifier and the concentration used affect deposit, but, in spite of the extensive literature on the role of emulsifiers in emulsification and deposition, no satisfactory method of evaluating emulsifiers for spray oils other than by actual trial imder field conditions has been found. A rather complete discussion of emulsifiers and the principles involved in emulsification is given in the work of Sutheim (21),... 

There exists, in the literature on high internal phase emulsions, a small number of publications on possible applications of HIPEs, involving a diverse range of topics. The production of petroleum gels as safety fuels is one such example [124,125] this was mentioned in the section on non-aqueous HIPEs. The main advantage over conventional fuels is the prevention of spillage, which reduces the risk of fire in an accident. Also, studies on the flash-point of emulsified fuels [127] showed a considerable increase, compared to the liquid state, for commercial multicomponent fuels. In addition, there may be an enhancement of the efficiency of combustion of the fuel on emulsification, as it is known that a small amount of water in fuel can improve its performance [19]. 

The use of albumin microparticles as a drug delivery system was first suggested by Kramer (1974) and several methods for their production were subsequently developed (Gupta and Haung 1989). Most methods involved the application of emulsification methodology and factors involved in this process have been evaluated by a number of authors. However, studies of the in vitro disintegration process of protein microspheres, induced by the presence of protease enzymes in the environment, are limited (El-Samaligy and Rohdewald 1983). 

The top-down approach involves size reduction by the application of three main types of force — compression, impact and shear. In the case of colloids, the small entities produced are subsequently kinetically stabilized against coalescence with the assistance of ingredients such as emulsifiers and stabilizers (Dickinson, 2003a). In this approach the ultimate particle size is dependent on factors such as the number of passes through the device (microfluidization), the time of emulsification (ultrasonics), the energy dissipation rate (homogenization pressure or shear-rate), the type and pore size of any membranes, the concentrations of emulsifiers and stabilizers, the dispersed phase volume fraction, the charge on the particles, and so on. To date, the top-down approach is the one that has been mainly involved in commercial scale production of nanomaterials. For example, the approach has been used to produce submicron liposomes for the delivery of ferrous sulfate, ascorbic acid, and other poorly absorbed hydrophilic compounds (Vuillemard, 1991 ... 

Emulsion Capacity is the property of the protein product solution or suspension to emulsify oil. The measurement is of the maximum amount of oil that the mixture will emulsify without losing its emulsion characteristics. The steps involved in this test are 1) Hydration - formation of the aqueous mixture. 2) Oil addition - with agitation the cause of emulsification. 3) Stress - a result of the heat generated during emulsification. 

Several detailed discussions have described the complex theories of emulsion technology (1, 2, > 1 ) To summarize these theories, emulsifiers are essential for emulsion formation and stabilization to occur these surface-active compounds reduce the surface and interfacial tensions between two immiscible liquids, but this property accounts for only part of the mechanisms at work in emulsification. Three separate mechanisms that appear to be involved in formation of a stable emulsion include ... 

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