What are the basic characteristics of Surfactant

1.Surface activity and Surfactant.

Add a soluble substance, such as ethanol or soap, to water. The surface tension of aqueous solutions will be reduced to varying degrees, this phenomenon is generally called surface activity. For soap, when its concentration is very low, the surface tension of the soap with the increase in the concentration of a sharp decline. Therefore, it can be concluded that soap has the basic properties of Surfactant. Further studies have shown that when Surfactant is added to water, H is enriched on the surface of the solution and adsorbed under J. Therefore, Surfactant is a substance that, when added to water in small amounts, can significantly reduce the surface tension (or interfacial tension) of the water or solvent on the one hand, and, on the other hand, a series of unique functions such as wetting/anti-wetting, emulsifying/demulsifying, foaming/defoaming etc. .

2.Structural characteristics of Surfactant

Although Surfactant are diverse and have different functions, their molecular structures share a common feature that they are all composed of hydrophilic and lipophilic groups (or hydrophobic groups) , hydrophilic groups can bind to water molecules to make Surfactant soluble in water. It can also be said that the water solubility of Surfactant depends mainly on the number, strength and connection position of hydrophilic groups in the molecular structure, it also depends on the proportion of hydrophilic and lipophilic groups in the molecular structure. For Surfactant molecules, the common hydrophilic groups include carboxylic acid group, sulfonic acid group, sulfate group, hydroxyl group, ether group, amino group, polyoxyethylene group, etc. . The lipophilic group can make the deactivation agent dissolve in the oil, the common lipophilic groups include straight-chain or branched aliphatic alkyl groups (such as dodecyl, octadecyl) , aryl groups (such as phenyl, naphthalene) and alkyl aryl groups (such as butylnaphthalene, dodecyl benzene) .

It is because of the amphiphilic (hydrophilic and hydrophilic) structure of the surfactant, so it can change the surface (or interface) activity, and thus produce this practical characteristics. For example, Surfactant can be dissolved in water and oil at the same time, or by its “Bridging” function to mix oil and water, thus providing emulsification, decontamination and wetting. In addition, the Surfactant can promote the separation and crushing of solid particles and make them evenly dispersed in the liquid, and can disperse air in the liquid to form foam and maintain stability without bursting.

3.The personality traits of a Surfactant

The personality traits of Surfactant include anionic, cationic, non-ionic and hermaphrodite Surfactant. The anionic Surfactant include carboxylate, sulfonate, sulfate, phosphate, Surfactant; Cationic Surfactant include fatty amine salts and alkyl ring nitrogen-containing heterocyclic salts, non-ionic Surfactant include Polyethylene glycol and fatty acid polyol esters non-ionic Surfactant; Amphoteric Surfactant can be divided into betaine, amino acids, lecithin and imidazoline derivatives according to the structure of their cationic Surfactant According to the structure of anion part, it can be divided into carboxylate, sulfate, sulfonate and phosphate. They are characterized by their ability to react with cations or anions under different conditions. These Surfactant have good detergency, foaming and emulsifying power, and are resistant to acid, alkali and hard water, and anti-static and bactericidal effect, some varieties also have good slow dyeing and color and other special functions.