Surfactant and Water

S. S. Ashrawi. Hot water, surfactant, and polymer flooding process for heavy oil. Patent US 5083612,1992. 

Throughout the process, water, surfactant, and NAPL are recovered (as much as possible) for reuse and/or recycling. Many of the aboveground leaching facilities are essentially closed-loop systems. In most cases, the resulting clean soil can be used for backfill, landscaping, or similar purposes. 

In this experiment we will use various experimental techniques to attempt to identify the structures formed by a range of oil, water, surfactant and co-surfactant mixtures. The clues to this identification will come from ... 

In the preparation of a polymer latex, the initial relationship of water, surfactant, and monomer concentration determines the number of particles present in the reaction vessel. Once the process is underway, further addition of monomer does not change the number of latex particles. If such additional... 

Liquid crystal As the name implies, this is an ordered yet fluid phase in which water, surfactant, and solubilizate combine to form anisotropic, organized structures. These are called lyotropic mesomorphic phases, as opposed to thermotropic mesomorphs, which form when certain organic crystals are heated. 

These compounds differ from other surfactants in the pronounced sensitivity of their association structural organization to temperature. This characteristic feature was noted very early by Shinoda (3) with regard to their micellar association and solubilization. A corresponding sensitivity may also be observed in the strong dependence of the liquid crystalline regions in phase diagrams of the system water, surfactant, and hydrocarbon (4). 

The formation of microemulsions usually involves a combination of oil, water, surfactant, and cosurfactant. The tendency toward a w/o (oil-in-water) or an o/w (water-in-oil) microemulsion is... 

There is a considerable patent art concerning preparation of transparent mixtures of water with low molecular weight silicone oils using polymeric silicone surfactants. Some representative early references are Keil [47], Gee [48, 49], Gum [50] and Terae [51]. These compositions are called micro emulsions in the patents in the sense of being transparent mixtures of water, surfactant and oil - but note that they are transparent because of small particle size or because of index of refraction matching. 

Microemulsions are thermodynamically stable, clear fluids, composed of oil, water, surfactant, and sometimes co-surfactant that have been widely investigated during recent years because of their numerous practical applications. The chemical structure of surfactants may have a low molecular weight as well as being polymeric, with nonionic or ionic components [138-141]. For a water/oil-continuous (W/O) microemulsion, at low concentration of the dispersed phase, the structure consists of spherical water droplets surrounded by a monomolecular layer of surfactant molecules whose hydrophobic tails are oriented toward the continuous oil phase (see Fig. 6). When the volume fractions of oil and water are high and comparable, random bicontinuous structures are expected to form. 

The inverse micellar solubility areas in systems of water, surfactants and a third amphiphilic substance frequently are of a shape according to Fig. l. iZ/ Such shapes are also found in W/0 microemulsions —when water solubility is plotted against cosurfactant/surfactant fraction. 

Figure 2. Starting with the conditions of the three basic components—water, surfactant, and co-surfactant—the microemulsions are easily shown to be a part of the inverse micellar area...

This is best illustrated by what happens when the amount of salt is increased, for fixed amounts of oil, water, surfactant and cosurfactant (18-20). For relatively low amounts of salt, an oil in water microenulsion coexists with excess oil phase at sufficiently high salt content, a water in oil microemulsion is in equilibrium with excess water phase, while at intermediate salinities, a (middle phase) microemulsion coexists with both water and oil excess phases. 

After the reactor has been charged with water, surfactant, and any optional paraffin antifoulant, it is brought to temperature and then pressurized with VDF and optional comonomer(s). The reaction pressure is maintained during polymerization course by adding monomer(s) to the reactor. 

As mentioned previously, the requirements to prepare an emulsion include oil, water, surfactant, and energy, and this can be considered from the energy required to expand the interface, AAy (where AA is the increase in interfacial area when the... 

Unlike the experiments carried out below the cloud point temperature, appreciable solubilisation of oil was observed in the time frame of the study, as indicated by upward movement of the oil-microemulsion interface. Similar phenomena were observed with both tetradecane and hexadecane as the oil phases. When the temperature of the system was raised to just below the PITs of the hydrocarbons with C12E5 (45°C for tetradecane and 50°C for hexadecane), two intermediate phases formed when the initial dispersion of Li drops in the water contacted the oil. One was the lamellar liquid crystalline phase La (probably containing some dispersed water). Above it was a middle-phase microemulsion. In contrast to the studies below the cloud point temperature, there was appreciable solubilisation of hydrocarbon into the two intermediate phases. A similar progression of phases was found at 35°C using n-decane as the hydrocarbon. At this temperature, which is near the PIT of the water/decane/C Es system, the existence of a two-phase dispersion of La and water below the middle-phase microemulsion was clearly evident. These results can be utilised to optimise surfactant systems in cleaners, and in particular to improve the removal of oily soils. The formation of microemulsions is also described in the context of the pre-treatment of oil-stained textiles with a mixture of water, surfactants and co-surfactants. 

In summary, the use of micro emulsions offers several advantages for the combustion process. Besides the thermodynamic stability of the aqueous fuel (which automatically means that the energy input for the production is minimal), water, surfactants and freezing point-decreasing components that are homogeneously distributed on a nano-scale can be optimally used for the reduction of soot and NOx emissions. 

A relatively stable emulsion formulation may be prepared from a simple four component mixture oil, water, surfactant and fatty amphiphile. In practice, however, things are never this straightforward. In addition to the four principle components, a pharmaceutical emulsion... 

A microemulsion is a multicomponent (3-4 components) system, e.g., water in hydrocarbon (water/oil) or hydrocarbon in water (oil/water), surfactant, and cosurfactant, and generally it exists only in small concentration ranges. Nevertheless, the capacity for reactants and variability of solubilization properties are high and of practical interest [76]. On the basis of microemulsions Menger and co-workers developed a method for an economical environmental cleanup of chemical warfare contamination [77]. As an example of organometallic catalysis in a microemulsion, Beletskaya [78] performed palladium-catalyzed C—C coupling reactions in aqueous medium with a very high content of surfactant. 

Latex-based polymer materials can be either nature-made, as natural rubber [Stern, 1967 White, 1995], or synthetically made. The synthetically made latexes are commonly based on recipes of monomer, water, surfactant, and free radical initiator to induce chain polymerization [Lovell and El-Aasser, 1997 Wickson, 1993], However, recipes based on step polymerization are also well known, often resulting in crossUnked films [Walker and Shaffer, 1996], The resulting latex material consists of small particles, usually spherical, of 50-500 nm in diameter, dispersed in water. Alternately, polymers are sometimes emulsified after polymerization (direct emulsification, the product sometimes called artificial latexes) via agitation of a melt in the presence of water and surfactant (emulsifier), and sometimes organic solvent or plasticizer [Piirma, 1989]. 

In the pioneering work of Krieger and co-workers, monodisperse latices were prepared with mixtures of anionic and nonionic surfactants in the aqueous phase. Their mixtures of styrene (or vinyltoluene), water, surfactants, and initiator were stirred in a resin flask using a very large, specially designed stainless steel paddle. Stirring was at a very modest rate [76]. 

The physical picture of emulsion polymerization is based originally on the qualitative picture of Harkins [18] and the quantitative treatment of Smith and Ewart [19], followed by other contributions. Gilbert shaped the qualitative and quantitative picture of the emulsion polymerization process as it is now generally accepted [16]. The main components of an emulsion polymerization recipe are the monomer(s), dispersing medium (usually water), surfactant and initiator. 

In the colloidal system of water, surfactant, and volatile oil, only the surfactant will not evaporate. Hence, the relative amounts of the remaining two components in the vapor leaving at each point of the trajectory are directly obtained by the points at which the tangents to the evaporation curves intersect the water/oil axis [36]. 

Methyl(hydroxypropyl)cellulose sodium dodecyl sulfate and water surfactants and water 2010KA1 2010SAR... 

What are the factors that might control the water pool size It has been found by many workers that the most important controlling factor is the molar ratio w = [water] /[surfactant] and the nature of the continuous phase may not play a very significant role. Kotlarchyk etal. [148] studied the system NaA0T/n-decane/D20 by small-angle neutron scattering and proposed a relationship ... 

B.M. Coursey. No. We have not used gel scintillators because the scintillation yields are too low for these systems. It is certainly true that gel systems can incorporate more iron, and this is an advantage for low-level and biological assays of Fe. However, to obtain the maximum counting efficiency, concentrations of all quenching agents, including water, surfactant, and Fe, must be as low as possible. 

A microemulsion is water/hydrocarbon dispersion stabilized by an ionic surfactant such as a soap, alkyl sulphate or sul-phonate and most often also contains a cosurfactant in the form of a medium chain length alcohol (pentanol). Of these four components water, surfactant and cosurfactant are called the structure forming elements since they form colloidal association structures similar to the microemulsions with no hydrocarbon present. The formulation and preparation of microemulsions is greatly enhanced by a knowledge of these composition dependent structures, hence an introductory description of them will be given. 

In order to form a microemulsion hydrocarbon must be added and the triangular diagreun now becomes a tetrahedron. Figure 4. The amount of hydrocarbon is now represented by the perpendicular distance from the base plate. The result is (Friberg, 1976) that the water solubilization counted on the three structure forming elements water, surfactant and cosurfactant) remains constant. This means that point B representing 75 percent water in the base plane with zero hydrocarbon as point B" in the plane with 50% hydrocarbon represents 37.5 percent water. The total composition of point B" will be water 37.5%, hydrocarbon 50%, surfactant 3.125% and cosurfactant 9.375%. 

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