Surfactants greases

Uses Surfactant, grease emulsifier for hand dishwash, laundry, neutral and acidic hard surf, cleaners, personal care prods., all-puqx)se cleaners surf. lens, reducer Features Stable even in hot alkaline systems compal. with alkali, acid, and build-6rs... 

Although most greases offer some inherent protection against msting, additives, eg, amine salts, sodium sulfonate, cycloparaffin (naphthenate) salts, esters, and nonionic surfactants (qv), are often used to provide added protection against water and salt-spray corrosion. A dispersion of sodium nitrite has been particularly effective in some multipurpose greases. 

Sulfosahcyhc acid is prepared by heating 10 parts of sahcyhc acid with 50 parts of concentrated sulfuric acid, by chlorosulfonation of sahcyhc acid and subsequent hydrolysis of the acid chloride, or by sulfonation with hquid sulfur trioxide in tetrachloroethylene. It is used as an intermediate in the production of dyestuffs, grease additives, catalysts, and surfactants. It is also useful as a colorimetric reagent for ferric iron and as a reagent for albumin. Table 9 shows the physical properties of sahcyhc acid derivatives. 

Filter Cleaners. Grease and oils from bathers can affect filtration. Degreasers are employed to clean diatomaceous earth (DE) and sand filters. They can be surfactant or enzyme based. 

Surfactants are probably the materials which most affect the performance of alkali cleaners. Surfactants are complex chemicals which modify the solubility of various materials in, and their surface affinity for, oil and water. The diverse composite which makes up the surface of a metal object must be fully wetted out if the cleaner is to perform properly. Surfactants lower the surface tension to allow wetting out to occur. Oils and greases must either be dissolved off the surface or lifted from it surfactants assist in both areas. 

The removal of dirt and stubborn grease generally requires the use of aqueous-based, heavy-duty industrial cleaners. These cleaners may or may not contain traditional ingredients like caustic or phosphate (which can be replaced by silicates or organic surfactants). 

To remove fats, oils, and grease from our clothes, our hair, our bodies, and our dishes, we use products known as surfactants. These contain ingredients that make oil and water mix, forming tiny droplets out of oil slicks, so the droplets can be washed away in the rinse water. 

Surfactants have a hydrophilic side of the molecule that attaches to water, and a hydrophobic side of the molecule that avoids water. In the absence of oils, the hydrophobic side sticks out of the surface of the water drop. There is no longer any water at the surface to form a strong surface tension, so the water no longer beads up, but spreads. The hydrophobic end of the molecule is also free to attach to grease, fat, or oil on the surface, which aids in the spreading. 

Approximately 70,000 tons of silicone polymers are produced each year In the United States. Silicones are used as greases, caulking, gaskets, biomedical devices, cosmetics, surfactants, antifoaming agents, hydraulic fluids, and water repellents. 

Each micelle has a polar periphery and an oil-like core. When molecules of monomer collide with the solid surface of, say, a dirty plate, the non-polar ( hydrophobic ) end adsorbs to the non-polar grease. Conversely, the polar ( hydrophilic ) end readily solvates with water. Soon, each particle of oil or grease is surrounded with a protective coating of surfactant monomer, according to Figure 10.13. 

Having disguised each particle of oil or grease, it can readily enter solution while sheathed in its water-attracting overcoat of surfactant. And if the oil particles enter the solution, then the oil is removed from the plate, and is cleaned. 

This step is essential in the manufacture of detergent active ingredients as it converts the sulfonic acids or sulfuric acid esters (products produced by processes I-M) into neutral surfactants. It is a potential source of some oil and grease, but occasional leaks and spills around the pump and valves are the only expected source of wastewater contamination. A process flow diagram is shown in Figure 14. 

Fig. 24.2 summarizes the cleaning action of surfactants. The surfactant lines up at the interface and also forms micelles, or circular clusters of molecules. In both cases the hydrophobic end of the molecule gets away from water molecules and the hydrophilic end stays next to the water molecules (like dissolves like). When grease or dirt come along (primarily hydrophobic in nature) the surfactants surround it until it is dislodged from the substrate. The grease molecules are suspended in the emulsion by the surfactant until they can be washed away with freshwater. 

Casting waste—quench water solids, oil and grease, metals Textile dyeing wastewater solids, color, COD/BOD loading Oily emulsions without surfactants... 

In the detergency process, fatty materials (i.e. dirt, often from human skin) are removed from surfaces, such as cloth fibres, and dispersed in water. It is the surfactants in a detergent which produce this effect. Adsorption of the surfactant both on the fibre (or surface) and on the grease itself increases the contact angle of the latter as illustrated in Figure 4.7. The grease or oil droplet is then easily detached by mechanical action and the surfactant adsorbed around the surface of the droplet stabilises it in solution. 

The basic common denominator for all these applications is qualitatively well understood surfactants and their aggregates permit mixing, or at least close interaction, between phases or substances that are per se immiscible with each other -mostly oil and water. This is how grease is washed off from our hands when we use soap, the removal being mediated by micelles. In turn, micelles and vesicles permit the formation of an extraordinarily efficient interfacial system. Figure 9.3 gives a dramatic demonstration of this, showing that the total surface of a concentrated soap solution in your sink may well correspond to the surface of a stadium ... 

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