What are the commonly used alkyl glycoside surfactants?

2023-03-31 17:03:51

Commonly used alkyl glycoside surfactants are mainly coupling agents, higher fatty acids and their salts, unsaturated organic acids and silicones. The coupling agent is a commonly used mineral surfactant.

Crystal agglomeration refers to the phenomenon that crystals change from loose state to lumps. Agglomeration makes the fluidity of crystal particles worse, which directly affects the performance of the product. Adding a small amount of surfactant to the solution during the crystallization process of the product can effectively prevent the agglomeration of the product. Its mechanism of action is as follows: ①surfactant enters the crystallization system and forms a wrapping film on the surface of the crystal, which creates a mechanical isolation effect between the crystal grains; ②adsorbs on the surface of the crystal to form a hydrophobic layer, which prevents the moisture exchange between the crystal and the atmosphere; ③reduces The surface tension of the solution changes the interface contact angle between solid and liquid, reducing the capillary adsorption force of the crystal to the solution; ④ participates in the crystal production process, changes the relative growth rate of each crystal plane, improves the crystallization habit of particles, and reduces the crystal interface energy. thereby changing the crystal form. For example, alkyl sulfonate and its intermediate alkyl sulfonyl chloride, alkylbenzene sulfonate, sodium p-toluene sulfonate, sodium fatty acid, etc. can be used as anti-caking agents for crystal products.

Surface chemical modification is to partially coat the surface of the particle by means of chemical reaction or chemical adsorption between the surface active agent and the surface of the inorganic powder to make the surface of the particle organic, so as to complete the surface modification.

The SiC ultrafine particles were treated with the surfactant polyethylene glycol, and the molecular chains of polyethylene glycol were modified on the surface of the SiC particles, which acted as a steric barrier and prevented the re-agglomeration of the solid SiC particles. After the irregular shape or agglomerated SiC powder is treated with surfactant, the long molecular chain of surfactant is adsorbed on the particle surface defects and dangling bonds, which accelerates the disintegration of large particles or agglomerated particles, which is beneficial to improve the dispersion of SiC particles.

Using adipic acid and stearic acid to modify the surface of nano-zirconia powder, the results show that the carboxyl group (—COOH) in adipic acid and stearic acid and the hydroxyl group (—OH) on the surface of nano-zirconia particles The esterification reaction similar to acid and alcohol occurred, and a monomolecular film was formed on the surface, and the surface-modified nano-zirconia powder changed from polar to non-polar. At the same time, since the monomolecular film is adsorbed on the surface of the powder, the interaction force between the powders (including the intermolecular force and mechanical hinge force) is reduced, that is, the frictional resistance when the powder flows is reduced, thereby improving the fluidity of the powder. .