What are the functions of emulsions prepared from surfactants?

2022-10-17 11:30:32

Surfactant is used as the cleaning agent in the cleaning solution to reduce the interfacial tension between the cleaning solution and the dirt. The cleaning solution can first wet the dirt surface to make the dirt swell, and then penetrate into the dirt to disperse the dirt. If the dirt belongs to oil, the grease will first form a ball and gather on the metal surface, and the surfactant will squeeze in to separate the dirt from the metal surface and move it to the cleaning solution. The originally insoluble oil particles are surrounded in the surfactant micelle and "solubilized" in the cleaning solution, and will not be adsorbed on the metal surface again. When washing, if there is mechanical force, it will help the dirt to separate from the metal surface and improve the cleaning effect. In addition to the cleaning effect of the above cleaning agent, the emulsion prepared from the surfactant also has the similar solvent dissolution principle. The existence of the internal oil phase will greatly enhance its dissolution and cleaning effect on oil contamination. 

The ideal cleaning emulsion generally has the following four characteristics:

(1) The emulsion is stable, and the oil has strong solubility relative to oil contamination;

(2) The viscosity of oil phase is low, and it is easy to clean with water;

(3) Good oil phase, non volatile, non-toxic, and no pollution during cleaning;

(4) It is easy to demulsify and recycle.

Although the alkaline surfactant solution has the properties of wetting, emulsifying, dispersing and solubilizing, it has a great ability to remove light and heavy oil scales, but it has a poor ability to remove tar scales containing more coke tar pitch. At this time, organic solvents should be added. One is amphiphilic alcohols, such as isopropanol, which will increase the micelles and help non-polar organic substances insert into the micelle "fence", so that the ability to remove tar scales will be greatly enhanced.