Roles and Principles of the Surfactant

1. Emulsification of the surfactant

Due to the large surface tension of oil in water, when oil is dropped into the water and stirred vigorously, the oil is crushed into fine beads and mixed with each other to form an emulsion, but the stirring stops and the layers are re-stratified. If you add a surfactant and stir vigorously, it will not be easy to layer for a long time after stopping, which is the emulsification effect. The reason is that the hydrophobicity of the oil is surrounded by the hydrophilic group of the active agent, forming a directional attraction, reducing the work required to disperse the oil in water, and making the oil well emulsified.

2. The wetting effect of the surfactant

Parts are often coated with a layer of wax, grease or scaly substances that are hydrophobic. Due to the pollution of these substances, the surface of the parts is not easily wetted by water. When surfactants are added to the aqueous solution, the water droplets on the parts are easily dispersed, which greatly reduces the surface tension of the parts and achieves the purpose of wetting.

3. Solubilization of the surfactant

The oil can only be "dissolved" after adding a surfactant to the oil, but this dissolution can only occur when the concentration of the surfactant reaches the critical concentration of the colloid, and the solubility is determined according to the solubilization object and properties. In terms of solubilization, long hydrophobic gene hydrocarbon chains are stronger than short hydrocarbon chains, saturated hydrocarbon chains are stronger than unsaturated hydrocarbon chains, and the solubilization effect of nonionic surfactants is generally more significant.

4. The dispersion of the surfactant

Solid particles such as dust and dirt particles are relatively easy to aggregate together, and are prone to sedimentation in water. The molecules of surfactants can divide the solid particle aggregates into fine particles, so that they can be dispersed and suspended in the solution, which can promote the uniformity of solid particles. dispersion effect.

5. Foaming effect of the surfactant

The formation of foam is mainly due to the directional adsorption of the active agent, which is caused by the reduction of the surface tension between the gas and liquid phases. Generally, low molecular weight active agents are easy to foam, high molecular weight active agents have less foam, yellow myristate has the highest foamability, sodium stearate has the worst foamability, and anionic surfactants have better foamability and foam stability than non-ionic surfactants, such as sodium alkyl benzene sulfonate has strong foaming. Commonly used foam stabilizers include fatty alcohol amides, carboxymethyl cellulose, etc., and foam inhibitors include fatty acids, fatty acid esters, polyethers, etc. and other nonionic surfactants.

WEIHENG produces different types of surfactants for sale, including cationic, nonionic, and amphoteric surfactants. Feel free to contact us if you need any of related products.