Wang Wanxu Tai Xiumei
Surfactant is a substance that can significantly change the interface state of the solution system by adding a small amount of surfactant. Human understanding of surfactants begins with detergents. As early as 2500 BC, the Sumerians of the Euphrates already knew how to make soap from sheep oil and plant ash, and soap that can still be used today was found during the excavation of the Roman site of Pompeii. Until the middle of the 19th century, soap was the only surfactant that people used. With the advance of the second Industrial Revolution, Turkish red oil (sulfonated castor oil) appeared, which is the first detergent made from vegetable oil, which has good water solubility and solves the problem that soap is not resistant to hard water and acid. With the development of the petroleum industry, petroleum sulfuric acid (green oil) has become the first detergent made from mineral oil. During the first World War, Germany developed a short-chain alkylnaphthalene sulfonate surfactant, Nekal, from coal tar derivatives. In the 1930s, long-chain alkylbenzene sulfonates began to enter the market and dominate the detergent industry as the main raw material of detergents. After World War II, Germany began the research on ethylene glycol derivatives and developed many Nonionic surfactants with excellent properties, which greatly promoted the development of liquid detergents. After the 1950s, with the progress of chemical technology, the number of surfactants in China has been increasing, and there are more than 4000 kinds of surfactants.
The Chinese nation, which has a brilliant civilization, used plant ash to wash clothes as early as the Zhou Dynasty. "Crown dirt, and ash request gargle; clothes dirt, and ash request" are recorded in the Book of Rites. During the Wei and Jin dynasties, it was found that soap horn and bath beans had the effect of removing stains. The fruit of Zaojiao tree-Zaojiao, soaked in water can produce foam, has a certain decontamination effect, and pure natural does not hurt hands. Bath bean is to clean the pig pancreas, then grind the excess fat of the pancreas into a paste, add bean powder and spices to it, mix it evenly, and dry it naturally. These two detergents have been in China for more than a thousand years and have witnessed the rise and fall of Chinese history. It was not until the early days of the Republic of China that Western soap-making was introduced, and China began to switch to soap, which was called "foreign pancreas". Since the 1950s, China began to vigorously develop the industry of surfactants and synthetic detergents. Through the unremitting efforts of researchers, the development of Chinese surfactants comes from behind and is in the forefront of the world.
Foaming agents in surfactants can form rich foams on the surface of the water.
Soap began to be used in large quantities in the middle of the 19th century
The ancients used burned plant ash and sheep oil to make soap.
Soap horn with decontamination effect
Surfactant molecules are generally composed of two parts, one is hydrophilic head group, the other is hydrophobic tail chain. According to the type of hydrophilic head group, surfactants can be divided into ionic surfactants and Nonionic surfactants. The head group of ionic surfactants can be dissociated in water. according to the types of hydrophilic ions, ionic surfactants can be divided into cationic, anionic and zwitterionic surfactants. Nonionic surfactants do not dissociate in aqueous solution and no ions are formed.
Anionic surfactant has good emulsification, dispersion, solubilization, foaming and decontamination ability. it is the most widely used surfactant, mainly used as detergent, and the most commonly used is linear alkylbenzene sulfonate. Cationic surfactants have positive charge and strong adsorption capacity. Quaternary ammonium salt cationic surfactants are added to daily contact with hand sanitizers, detergents, band-aids and other products to play a role in sterilization. Amphoteric surfactants have good biodegradability, resistance to hard water and electrolytes, low toxicity and low stimulation, and have good compounding properties with other surfactants. They can be used as high-grade detergents, softeners, antistatic agents, emulsifiers and fungicides. Nonionic surfactant has strong wetting, emulsifying and decontamination ability, and has good compounding performance with other surfactants. Nonionic surfactants from natural plants, such as alkyl glycosides (APG), can be used in infant skin care products and sensitive skin care products.
Surfactant has the reputation of "industrial monosodium glutamate" and special molecular structure, which makes it widely used in various industries. With the further study of surfactant, people have a deeper understanding of its properties and functions. At present, surfactants are not only limited to the field of detergents, but also widely used as dispersants, softeners, catalysts, waterproofing agents, antifouling agents, lubricants, antidust agents, preservatives, spreading agents, thickeners, antistatic agents, antideposition agents, surface modifiers and other functional reagents. It plays an important role in cosmetics, food, pesticides, paints, petrochemicals, mining, medicine, construction and other fields.
Schematic diagram of molecular structure of surfactant (for pictures / Taixiumei)
Schematic diagram of detergent decontamination process (for pictures / Taixiumei)
Nonionic surfactant from natural plants-alkyl glycosides (pictured / Taixiumei)
Surfactants with a long history are not out of date with the progress of the times, on the contrary, they are constantly integrated into various emerging fields and play a finishing role in a variety of products. In the future, surfactants will keep pace with the times and develop in the direction of green, environmental protection and functionalization, and strive to ensure the green and ecological safety of products while focusing on functionality, so as to reduce the impact on the environment and harm to the human body.
Main functions and applications of Surfactants (Picture / Taiwan Xiumei)
