Emulsifier, removal

Emulsifiers. Removing the remover is just as important as removing the finish. For water rinse removers, a detergent that is compatible with the remover formula must be selected. Many organic solvents used in removers are not water soluble, so emulsifiers are often added (see Emulsions). Anionic types such as alkyl aryl sulfonates or tolyl fatty acid salts are used. In other appHcations, nonionic surfactants are preferred and hydrophilic—lipophilic balance is an important consideration. 

Emulsifier Removal by Other Methods One approach to reduce the emulsifier content of fluoropolymer dispersions is based on the thermal degradation of the emulsifiers at sufficiently high temperatures [43]. To avoid adverse effects for the dispersion, a nonionic stabilizer is added. The stabilized dispersion is heated... 

From this work, it is concluded that 1. the ion exchange of latex to remove adsorbed emulsifier and solute electrolyte may cause flocculation of the latex particles, particularly those of small particle size 2. all three mechanisms proposed for the flocculation are probably operative, but the destabilization because of emulsifier removal and the flocculation by polyelectrolytes leached from the ion-exchange resin account for most of the flocculation ... 

The presence of high concentrations of waxes and mucilagenous materials in the oil makes winterization of some oils difficult, hi such cases filtration of the oil is hindered by the high viscosity of the cold oil, the lack of uniformity in crystal formation of the waxes, and the presence of mucilaginous materials which coat the wax crystals (Morrison and Robertson, 1975). Washing crude oil with emulsifiers removes waxes and the majority of PLs and helps with the subsequent winterization process. Solvent winterization from acetone or an 85/15 acetone-hexane mixture is shown to be effective in peanut and sunflower oil winterization by reducing viscosity. In addition, small amounts of diatomaceous earth addition increased the filtration rate of cold sunflower seed oil by a factor of four. 

A cyUndrical or, preferably, a pear-shaped separatory funnel (Fig. II, 1, 5, e and d) of 10-15 ml. capacity is usually employed for the separation of immiscible liquids. For separations on a smaller scale, a dropper pipette may be used the upper layer is best removed with a bent pipette as in Fig. XII, 1,3. For liquids which tend to emulsify, centrifugation (a hand centrifuge is satisfactory) will usually produce a clean line of demarcation between two immiscible liquids. 

Wash with water to remove any salts made from other contaminants and to crash out any partially dissolved Safrole (it might emulsify from the shaking, if so, add common table salt to help it crash). 

A significant fraction of the body s cholesterol is used to form bile acids Oxidation m the liver removes a portion of the CsHi7 side chain and additional hydroxyl groups are intro duced at various positions on the steroid nucleus Cholic acid is the most abundant of the bile acids In the form of certain amide derivatives called bile salts, of which sodium tau rocholate is one example bile acids act as emulsifying agents to aid the digestion of fats... 

The second generation includes latices made with functional monomers like methacrylic acid, 2-hydroxyethyl acrylate [818-61 -17, acrylamide/75 -(9ti-/7, 2-dimethylaminoethylmethacrylate [2867-47-2] and sodiumT -vinyl-benzenesulfonate [98-70-4] that create in polymeric emulsifier. The initiator decomposition products, like the sulfate groups arising from persulfate decomposition, can also act as chemically bound surfactants. These surfactants are difficult to remove from the latex particle. 

Solvent Evaporation. This encapsulation technology involves removing a volatile solvent from either an oil-in-water, oil-in-oil, or water-in-oH-in-water emulsion (19,20). In most cases, the shell material is dissolved in a volatile solvent such as methylene chloride or ethyl acetate. The active agent to be encapsulated is either dissolved, dispersed, or emulsified into this solution. Water-soluble core materials like hormonal polypeptides are dissolved in water that contains a thickening agent before dispersion in the volatile solvent phase that contains the shell material. This dispersed aqueous phase is gelled thermally to entrap the polypeptide in the dispersed aqueous phase before solvent evaporation occurs (21). 

Over time, finish components tend to separate and migrate within the fiber and throughout the yam package. With nylon, the ionic emulsifiers and antistats tend toward the core of the fiber whereas the hydrocarbon lubricants remain on the surface. It is, therefore, essential to scour yams and fabrics at neutral to basic pH to reemulsify the lubricant and remove the finish emulsifier prior to dyeiag. In formulating any new finish, environmental issues such as biodegradabihty, water and air pollution must be considered (137). 

Liquid soil can be removed by dkect emulsification and solubiLkation as well as by roU-up. Oils that are more readily emulsified or solubilked are removed more rapidly and more completely. 

Acidic Hydrolysis. Hydrolysis of esters by use of water and a mineral acid leads to an equiUbrium mixture of ester, alcohol, and free carboxyHc acid. Complete reaction can only be achieved by removal of alcohol or acid from the equiUbrium. Because esters have poor solubiUty in water, the reaction rate in dilute acids is fairly low. Therefore, emulsifiers such as sulfonated oleic acid or sulfonated aromatic compounds (TwitcheU reagent) are added to facihtate the reaction. 

Metalworking fluids contain mineral oils (refer to p. 80) or synthetic lubricants they are used neat or in admixture with water. They may contain small amounts of biocides, stabilizers, emulsifiers, coiTosion inhibitors, fragrances and extreme pressure additives. The formulations render them suitable for application to metal being worked, generally from a recirculatory system, to provide lubrication, corrosion protection, swarf removal and cooling of the tool and machined surface. 

When the primary target is oil removal, we should distinguish between the forms of oil. There are two forms of oil that we find in wastewater. Free oil is oil that will separate naturally and float to the surface. Emulsified oil is oil that is held in suspension by a chemical substance (Detergents - Surfactants) or electrical energy. When making an evaluation, free oil will normally separate by gravity and float to the surface in approximately 30 minutes. Emulsified oil is held in a molecular... 

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