Emulsifier surface active agents

Lipids are insoluble in water and an interfacial tension therefore exists between the phases when lipids are dispersed (emulsified) in water (or vice versa). This tension in toto is very large, considering the very large interfacial area in a typical emulsion (section 3.7). Owing to the interfacial tension, the oil and water phases would quickly coalesce and separate. However, coalescence (but not creaming) is prevented by the use of emulsifiers (surface active agents) which form a film around each fat globule (or each water... 

Surfactants play an important role in the processing of metals. They are used in many treatment steps as emulsifiers, surface-active agents, lubricants, cleaning agents and corrosion inhibitors. 

Emulsifiers (surface active agents) assist to stabilize the pH of the dispersion and to decrease its surface tension to obtain improved wettability. The emulsifiers are always oriented on the interface between polymer particles and the aqueous phase. Small amounts must be added to avoid loss in bonding characteristics. 

Suspensions of oil in water (32), such as lanolin in wool (qv) scouring effluents, are stabilized with emulsifiers to prevent the oil phase from adsorbing onto the membrane. Polymer latices and electrophoretic paint dispersions are stabilized using surface-active agents to reduce particle agglomeration in the gel-polarization layer. 

Emulsification is essential for the development of all types of skin- and hair-care preparations and a variety of makeup products. Emulsions (qv) are fine dispersions of one Hquid or semisoHd ia a second Hquid (the contiauous phase) with which the first substance is not miscible. Generally, one of the phases is water and the other phase is an oily substance oil-ia-water emulsions are identified as o/w water-ia-oil emulsions as w/o. When oil and water are mixed by shaking or stirring ia the absence of a surface-active agent, the two phases separate rapidly to minimize the iaterfacial energy. Maintenance of the dispersion of small droplets of the internal phase, a requirement for emulsification, is practical only by including at least one surface-active emulsifier ia the oil-and-water blend. 

Poly(vinyl alcohol) will function as a non-ionic surface active agent and is used in suspension polymerisation as a protective colloid. In many applications it serves as a binder and thickener is addition to an emulsifying agent. The polymer is also employed in adhesives, binders, paper sizing, paper coatings, textile sizing, ceramics, cosmetics and as a steel quenchant. 

Two-component waterborne urethane dispersions are similar to the one-component PUD s in that a polyurethane dispersion comprises one of the two components. The second component is usually a crosslinker from the following classes of materials (a) polyisocyanates, (b) aziridines, (c) polycarbodiimides, and (d) epoxies. Many of the crosslinkers are not inherently water-soluble or water-dispersible. Therefore, they must be modified with surface active agents themselves, so as to become emulsifiable in water. 

Orimulsion is a relatively new fuel that is available for the gasification process. Orimulsion is an emulsified fuel, a mixture of natural bitumen (referred to as Orinoco-oil), water (about 30%), and a small quantity of surface active agents. Abundant Orinoco-oil resei ves he under the ground in the northern part of Venezuela. 

Surface active agent. Any of a wide range of detergents, emulsifiers, dispersants, defoamers, etc., that tend to reduce the surface tension of water and improve its wetting power. 

Thus, in the relatively simple case of oil in water emulsions, where a surface active agent such as a soap is used as the emulsifying agent, it is known that the soap adsorbed on the surface of the oil particles decreases the interfacial tension, thus stabilizing the emulsion. The adsorbed soap ions also give a net electrostatic charge to the dispersed oil droplets, serving to repel other oil droplets, with the net effect that flocculation is hindered (and stability is increased). It is even possible to measure the amount of adsorbed soap ions and to calculate the values of the surface potential. 

Emulsifier/plasticizer, dispersing agent, surface active agent, surfactant, wetting agent Emulsifying salt/melding salt, sequestrant... 

The stabilizing of aqueous latexes succeeded by using emulsifiers (anionic, nonionic) and/or their mixture, steric stabilizators (polyvinyl alcohol (PVOH), hydroxyethyl cellulose, polyethylene glycol, new protective colloids etc.), and polymerizable surfaces active agents, in general. Vinyl acetate (VAc) emulsion homopolymers and copolymers (latexes) are widely used as binders in water-based interior and exterior architectural paints, coatings, and adhesives, since they have higher mechanical and water resistance properties than the homopolymers of both monomers [2, 4, 7]. 

HLB values decrease as the solubility of the surface-active agent decreases in water. Solubility of cetyl alcohol in water (at 25°C) is less than a milligram per liter. It is thus obvious that, in any emulsion, cetyl alcohol will be present mainly in the oil phase, while SDS will be mainly found in the water phase. Empirical HLB values are found to have significant use in emulsion technology applications. It was shown that HLB is related, in general, to the distribution coefficient, KD, of the emulsifier in the oil and water phases ... 

Other paint stripper ingredients include surface-active agents (surfactants), emulsifiers, thickeners, sealants, and corrosion inhibitors. Thickeners such as methyl cellulose derivatives are used to thicken the stripper so that it can be brushed onto vertical surfaces. Sealants snch as crude or refined paraffin act to retard evaporation of the CH2CI2 so that the stripper remains effective over a long period of time. 

Duponol. Trademark of duPont Co for a line of surface-active agents of the alcohol-sulfate type. They have detergent emulsifying, dispersing, and wetting properties used in the textiles, paper, leather, electroplating, etc industries... 

The emulsifier is a surface-active agent which alters the characteristics of the water-oil interface. 

Strangely enough, demulsifiers are similar in nature to emulsifiers. They are surface-active agents with certain built-in properties which make them effective in disrupting the effect of the emulsifier. The action is all at the water-oil interface so the demulsifier must get there to do its job The faster It gets there, the better job... 

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