3. Mechanochemical/chemical coating composite modification process
Surface modifier is added in the process of mechanical force or fine grinding and ultrafine grinding, and the surface chemical coating of particles is modified at the same time as the particle size decreases. This kind of composite surface modification process can simplify the process, some surface modifiers also have a certain degree of grinding aid, can improve the grinding efficiency to a certain extent.
The disadvantage is that the temperature is not easy to control; In addition, due to the continuous crushing of particles in the process of modification, new surfaces are produced, and the coating of particles is difficult to be uniform, so it is necessary to design the addition method of surface modifier to ensure uniform coating and high coating rate. In addition, if the heat dissipation of the grinding equipment is not good, the local excessively high temperature rise in the process of strong mechanical force may cause the decomposition of part of the surface modifier or the destruction of molecular structure.
4. Inorganic precipitation reaction/chemical coating composite modification process
Surface chemical coating modification after precipitation reaction modification is essentially an inorganic/organic composite modification process. This composite modification process has been widely used in the surface modification of composite titanium dioxide, that is, on the basis of coating SiO2 or Al2O3 film with precipitation, then using titanate, silane and other organic surface modifier TiO2/SiO2 or Al2O3 composite particles surface organic coating modification.
5, physical coating/chemical coating composite modification process
A process in which particles are physically coated, such as metal coated or coated, followed by surface organic chemical modification.