What are surfactants
Surfactants
Surfactants are a large group of organic compounds that are highly characterized by their properties, extremely flexible and wide range of applications, and great practical value.
Surfactants have been used as emulsifiers, detergents, wetting agents, penetrating agents, foaming agents, solubilizers, dispersants, suspending agents, cement water reducing agents, fabric softeners, leveling agents, color-fixing agents, biocides, catalysts, water repellents, antifouling agents, lubricants, antacid fogging agents, dust-proofing agents, anticorrosive agents, spreading agents, thickening agents, permeable agents, flotation agents, leveling agents, oil-repellents, anticaking agents, deodorizers, antistatics, surface modifiers, and so on. It can be used in daily life and many industrial and agricultural production fields as dozens of functional reagents, such as surface modifiers.
They are used as auxiliaries or additives in traditional industries such as food, paper, glass, petroleum, chemical fiber, textile, printing and dyeing, paint, medicine, pesticide, metal processing, new materials, construction, etc., as well as in the field of high and new technology.
Although they are often not the main body of the industrial product, but can play a key role in the production of a variety of products as a finishing touch. Its dosage is not large, but it can play a key role in increasing product variety, reducing consumption, saving energy and improving quality.
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An in-depth look at surfactants
A surfactant is a substance that significantly reduces the surface tension of a target solution. It has fixed hydrophilic and lipophilic groups that are oriented on the surface of the solution. The molecular structure of surfactant is amphoteric: hydrophilic group at one end, hydrophobic group at the other end; hydrophilic groups are often polar groups, such as carboxylic acid, sulfonic acid, sulfuric acid, amino or amine groups and their salts, hydroxyl, amide, ether bonds, etc., can be used as polar hydrophilic groups; and hydrophobic groups are often nonpolar hydrocarbon chains, such as more than 8 carbon atoms hydrocarbon chain. Surfactants are divided into ionic surfactants (including cationic surfactants and anionic surfactants), nonionic surfactants, amphoteric surfactants, complex surfactants, and other surfactants.
Introduction
Surfactant is a substance that can make the interfacial state of the solution system change significantly by adding a small amount of it. It has fixed hydrophilic and lipophilic groups, which can be arranged directionally on the surface of the solution. The molecular structure of surfactant has amphiphilic: one end is hydrophilic group, the other end is hydrophobic group; hydrophilic groups are often polar groups, such as carboxylic acid, sulfonic acid, sulfuric acid, amino or amine groups and their salts, hydroxyl, amide, ether bonds, etc. can also be used as polar hydrophilic groups; and hydrophobic groups are often nonpolar hydrocarbon chains, such as more than 8 carbon atoms hydrocarbon chain. Surfactants are divided into ionic surfactants (including cationic surfactants and anionic surfactants), nonionic surfactants, amphoteric surfactants, complex surfactants, and other surfactants.
History of origin
(1) 2500 B.C.E. – 1850 Sheep’s Oil and Grass Ash for Soap Manufacturing
Goat oil – tricarboxylic acid ester referred to as triglyceride, hydrolyzed by alkali → carboxylate + monoglyceride + diglyceride + glycerol
In the middle of the 19th century
On the one hand, soap began to achieve industrialized mass production, on the other hand, there is also the emergence of chemically synthesized surfactants.
②The appearance of Turkish red oil:
Turkey red oil that castor oil and sulfuric acid reaction products, castor oil for ricinoleic acid triglyceride, deeply sulfonated, acid and hard water resistant
(iii) In the early 19th century, detergents were prepared from mineral raw materials.
The development of the petroleum industry → petroleum sulfuric acid (green oil). Sulfonated mixture of wax and tea, dissolved in acid, greenish-black, neutralized with alkali to produce. Petroleum sulfonic soap has good water solubility and is called sodium green (first detergent made from mineral raw materials). During World War I, grease appeared, coal production → coal chemical industry developed → short-chain alkyl, nesulfonate surfactants, such as propyl nesulfonate, butyl nesulfonate
1920-1930 fatty alcohol sulfation → alkyl sulfates. 1930s, long chain alkyl, phenyl appeared in the United States. After World War I, Germany developed ethylene glycol derivatives, such as polyethylene glycol Derivatives of products, polyethylene glycol and a variety of organic compounds (including alcohols, acids, esters, amines, amides), such as the combination of a variety of excellent performance of nonionic surfactants.
Surfactants and synthetic detergents to form an industry can be traced back to the 1930s, to petrochemical raw materials derived from synthetic surfactants and detergents to break the dominant situation of soap. After more than 60 years of development, in 1995 the world’s total output of detergents reached 43 million tons, of which 9 million tons of soap. According to experts’ prediction, the world’s population will double from 2000 to 2050, and the total amount of detergents will increase from 50 million tons to 120 million tons, a net increase of 1.4 times, which is an encouraging figure.
China’s surfactant and synthetic detergent industry began in the 1950s, and although it started late, it has developed rapidly. in 1995, the total amount of detergents had reached 3.1 million tons, second only to the United States, ranking second in the world. The production of synthetic detergents rose from 400,000 tons in 1980 to 2.3 million tons in 1995, a net increase of 4.7 times, and an average annual growth rate of more than 10% of the rate of growth. According to the forecast of Chinese authorities, the total amount of detergents will reach 3.6 million tons in 2000, of which synthetic detergents will reach 655,000 tons. Among them, the surfactant varieties with an output of more than 10,000 tons include: sodium straight-chain alkylbenzene sulfonate (LAS), sodium aliphatic alcohol polyoxyethylene ether sulfate (AES), ammonium aliphatic alcohol polyoxyethylene ether sulfate (AESA), sodium lauryl sulfate (SDS), lauryl glutamate, nonylphenol polyoxyethylene ether (TX-10), ping pinga O, mono ester of stearic acid glyceryl ester, lignin sulfonate, heavy alkylbenzene sulfonate, Alkyl sulfonates (petroleum sulfonates), Diffuser NNO, Diffuser MF, Alkyl polyethers (PO-EO copolymers), Fatty alcohol ethoxylates (AEO-3), etc.
Definition
Any substance that can significantly reduce the surface energy of water when dissolved in water is called a surface active agent (SAA) or surface active substance.
Traditionally, surfactants have been regarded as a class of substances that can significantly reduce surface (boundary) tension even at very low concentrations. With the deepening of the research on surfactants, it is generally believed that any substance that can significantly change the surface (boundary) properties or the properties related to or derived from them at a low concentration can be categorized as a surfactant.
Surfactants are natural, such as phospholipids, choline, proteins, etc., but more synthetic, such as sodium octadecyl sulfate C18H37SO4Na, sodium stearate C17H35COONa, etc. . The range of surfactants is very broad (cationic, anionic, nonionic and amphoteric), providing a variety of functions for specific applications, including foaming effect, surface modification, cleansing, emulsions, rheology, environmental and health protection.
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