Stearates are Fatty Acid Esters that are Widely Used as Additives Because of Their Lubricating Properties

Stearates

Stearates are stearic acid salts or esters. Stearic acid have both hydrophilic and hydrophobic regions, allowing them to act as surfactants. They are frequently produced during saponification processes, which involve treating fats with strong bases to produce soap. The most common base is sodium hydroxide or potassium hydroxide, which results in the formation of sodium or potassium stearic acid. Many deodorants, rubbers, paints, and inks contain sodium stearate. In pharmaceutical manufacturing, magnesium and calcium stearic acid are frequently used as anti-adherent agents. Zinc stearic acid, also known as "zinc soap," has a wide range of industrial applications.

The simplest amphiphile molecules are sodium or potassium Stearates CH3-(CH2)14-COO- molecules, which are found in ordinary soap. In water, these molecules take the shape of micelles, which are roughly spheres with hydrophilic parts made of carboxylate ions with loosely bound cations all at the outer part of the sphere, forming H-bonds with the surrounding H2O molecules. Depicts hydrophobic parts confined within the interior of the sphere, which can accommodate smaller hydrophobic molecules. As a result, such amphiphile molecules act as detergents, allowing strongly hydrophobic molecules to be indirectly solvated into water, or incorporated into water but stearic acid without direct contact with H2O molecules. Soaps are detergents primarily composed of K+ stearic acid.

Cleaning agents in general are often composed of other amphiphiles, such as polyoxyethylene glycols, CH3-(CH2)n-(CH2-O-CH2)m-OH, which, unlike the preceding detergents, are not ionic. By the end of 2019, the Global Stearates Market is expected to be worth US$ 4,747.0 Mn in terms of value and volume of 1,604.3 Kilo Tons. As a result, they are less sensitive to the presence of other salts in water than stearic acid or dodecylsulfates. Another interesting detergent is sodium hexadecylbenzenesulfonate (CH3-(CH2)5)2-C=C6H4-SO3, which is used to extract oil from porous rocks. When dissolved in a liquid composed entirely of hydrophobic molecules, these amphiphile molecules may form a "reverse micelle," as depicted in the lower portion. All hydrophilic groups in this reverse micelle are directed towards the centre of the structure, where they can form H-bonds with H2O molecules of a nanodroplet of water (42), which can thus be indirectly solvated in oil.