Soaps, Detergents, and Shampoos

In strongly basic solutions, fats and oils undergo hydrolysis to produce glycerol and salts of fatty acids. Such reactions are called saponification reactions, and the sodium or potassium salts of the fatty acids formed are soaps. 

Principal fats and oils for soap making are tallow from beef and mutton, coconut oil, palm oil, olive oil, bone grease, and cottonseed oil. 

Pioneers prepared their soap by boiling animal fat with an alkaline solution obtained from tbe ashes of hardwood. The resulting lye soap could be salted out by adding sodium chloride, because soap is less soluble in a salt solution than in water. The crude soap made this way contained considerable caustic material (sodium hydroxide or potassium hydroxide) in addition to the soap molecules, but it did its job of cleaning quite well. 

The cleaning action of soap is explained by its molecular structure. When present in an oil—water system, the fatty acid anion in the soap moves to the interface between the oil and the water. 

One undesirable property of soaps is their tendency to form precipitates with Ga, Mg, and Fe + ions found in hard water. The resulting fatty-acid salts of these doubly positive ions are not as soluble in water as the Na+ ion salts. These less-soluble molecules appear as a scum that sticks to laundry and bathtubs, often containing trapped dirt, which makes it appear even worse. 

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Finally, saponins have commercial-industrial importance as they are used in the preparation of soaps, detergents, and shampoos. 

The largest end-use for KOH is the production of soaps and detergents. The cost handicap, again, does not prevent the use of KOH in specialty products, primarily liquid soaps, detergents, and shampoos. KOH is also used in glassmaking, in petroleum refineries for the removal of sulfides and mercaptans, in fertilizers, and in many other products. 

In 1969, autoradiography was used to study the localization of a series of radioactive germicides, dissolved in soap and nonsoap detergents and shampoo, across guinea pig skin [14]. It was shown that for all of the germicides in each of the vehicles studied, radioactivity was concentrated predominantly in the SC. The time of application (i.e., 10 min) was not, however, varied in these experiments. Therefore, it was not possible for the... 

Uses Humectant, moisturizer for personal care prods., sunscreens, soap bars, dry skin creams, shampoos, liq. soaps emollient in aq. and hydroalcoholic prods. foam modifier in detergent and shampoo systems humectant, solvent, and solubilizer for topical pharmaceuticals freezing pt. depressant Properties Pale yel. thin syrup pract. odorless sol. in water, alcohol, hydroalcoholic systems acid no. 1.0 max. iodine no. 1 max. sapon. no. 1.0 max. hyd. no. 205-225 100% cone. 

Alkyl Sulfates (AS) R-O-SO3 X R=C12-C18 Laundry detergents Wool-washing agents, soap bars and liquid bath soaps, hair shampoos, and toothpastes - STPs effluents C12-15 AS between 1.2 and 12 pg L 1 [15] Fast biodegradation under aerobic and anaerobic conditions. Effective removal in WWTPs [18]... 

Consumer products entail formulated products, such as soaps, detergents, bleaches, paints, solvents, glues, toothpaste, shampoos, cosmetics, skin care products, perfumes, and colognes intended for direct consumer use. 

Surfactants and Detergents Uses. Perhaps tire largest use of sulfonic acids is the manufacture of surfactants and surfactant formulations. In almost till cases, the parent sulfonic acid is an intermediate which is converted to a sulfonate prior to use. The largest volume uses for sulfonic acid intermediates arc the manufacture of heavy-duty liquid and powder detergents, light-duty liquid detergents, hand soaps (see Soaps), and shampoos. 

Substantivity refers to the ability of a perfume or a perfume material, applied in a diluted dispersion in water, to attach itself to a solid surface such as the skin (in the case of toilet soap and bath and shower products), the hair (in shampoos and conditioners), or textile fibers (in detergents and fabric softeners). It may refer also to their ability to stay on the surface when this is moistened (as in deodorants or water-proof sun protection products). 

As noted above, soaps form precipitates when used in hard water. In the 1930s, chemists developed synthetic detergents as a substitute for soap to avoid this problem. Synthetic detergents can be used in hard water without forming precipitates. Today, almost all laundry products and shampoos contain synthetic detergents. 

Noble metal nanoparticles such as gold, silver, and platinum nanoparticles are widely applied to human-contacting areas such as shampoo, soap, detergent, shoes,... 

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