Chemical modification and dispersion is to use the surface groups of nanoparticles to form chemical bonds with reactive organic compounds. The nanoparticles are soluble in organic media due to the branched chains or groups of organic compounds on the surface. dispersion in. There are usually two ways of chemical modification: one is to use the end groups of macromolecules to chemically react with the surface groups of nanoparticles to graft polymers onto the surface of nanoparticles. The second is to use the polymerization reaction of polymerizable organic small molecules on the active points of the nanoparticle surface to form a polymer layer on the nanoparticle surface.

In addition, the dispersion of nanoparticles is often carried out by combining physical dispersion and chemical dispersion. For example, in the process of ultrasonic dispersion, adding an appropriate amount of dispersant will significantly improve the dispersion effect. This is because the cavitation effect of ultrasound alone is difficult to prevent the reagglomeration of nanoparticles after ultrasound. After adding the dispersant, the particles can be prevented from agglomerating again, and at the same time, the ultrasonic effect is beneficial to the coating of the dispersant on the surface of the nanoparticles.

The dispersion behavior of nano-powder is similar to that of micro-powder with the same composition. However, due to the high activity of nano-powders, the surface morphology and adsorption properties have changed, and the dispersion of nano-powders has its own characteristics.

The control of the dispersion stability of nano-powder in the medium is the key to the wide application of nano-powder. There are generally two agglomeration states among nano-powder particles: soft agglomeration and hard agglomeration. Soft agglomeration is mainly caused by the van der Waals force and Coulomb force between particles. Because the force is weak, it can be eliminated by general chemical action or mechanical operation. In addition to the van der Waals force and Coulomb force, the reason for the formation of hard agglomeration is also related to the powder preparation process and process control. The force is strong and must be controlled by some special methods. For more dispersion methods of nano-powders, please contact us to discuss further with SAT NANO staff.