Dispersant is a chemical substance whose main function is to evenly disperse solid particles (especially small solid particles) in a solution, preventing them from gathering and settling. The principle of action of dispersants mainly includes the following aspects:
Obstruction of particle aggregation: Dispersants can interact with the surface of particles to form an adsorption layer or charge layer, causing particles to carry the same or opposite name charges, repelling each other, hindering the attraction between particles, and avoiding particle aggregation and precipitation.
Reducing surface tension: Dispersants can reduce the surface tension of liquids, making it easier for particles in the solution to be dispersed. The decrease in surface tension also helps to reduce the repulsive force between particles, further promoting dispersion.
Stable colloidal particles: Dispersants can form an adsorption layer or charge layer on the surface of particles, forming a stable colloidal particle system. This adsorption layer or charge layer can provide a certain charge barrier, prevent particle aggregation, and maintain the dispersed state of colloidal particles.
Promoting wetting and dispersion: Dispersants can improve the interaction between solution and solid particles, reduce the wetting angle of particles, and improve the dispersibility of particles in solution.
In short, dispersants form an adsorption layer or charge layer in the solution through the action of surfactants or adsorbents, hindering the aggregation and precipitation of particles, thereby achieving uniform dispersion of solid particles. This dispersion effect is very important for applications in many fields, such as industrial production of pigments, coatings, textiles, ceramics, etc. The particle dispersion and stability are inseparable from the role of dispersants.