The reason why nano copper oxide can excel in many fields is due to its unique properties. It has a small particle size and high activity, and exhibits excellent performance in magnetism, light absorption, thermal resistance, catalysts, and other aspects, laying a solid foundation for its application in multiple fields. Now, let's delve into its outstanding performance in different fields!
The difference in cohesive force between different powders is due to the type and strength of interparticle forces (van der Waals forces, capillary forces, electrostatic forces, etc.), and its core influencing factors include particle size, surface roughness, moisture content, and material properties, resulting in cohesive force that can span multiple orders of magnitude (from 10 ⁻⁶ N to 10 ⁻¹ N). This difference can be quantitatively described through the aggregation feature index, surface tension, and roughness correction model.
Ceramic particles have a wide range of applications in materials science, electronics, chemical engineering, medical and other fields, but due to their high surface energy and easy aggregation characteristics, dispersion has always been a key challenge in preparing high-performance ceramic materials. This article will introduce common types of ceramic particles and recommend suitable dispersants for different ceramic materials to improve dispersion stability and processing performance.
A particle refers to the smallest independent and discrete unit formed by the nucleation and growth of substances in a specific reaction system (such as combustion, precipitation, gas-phase synthesis, etc.), with regular or irregular geometric shapes. It can be understood as the most fundamental individual that is "innate" in the process of material formation.
Hydroxyl groups (- OH) can exhibit acidity or alkalinity on the surface of metal oxides in the form of proton reception or supply. By adjusting the quantity and distribution of hydroxyl groups, precise control of surface acidity and alkalinity can be achieved, thereby affecting the activation pathway and selectivity of catalytic reactions.
On unsaturated metal sites of metal oxides or semiconductor oxides (such as Ti4+, Fe3+), water molecules first adsorb in molecular form, followed by O-H bond cleavage, resulting in bridge or terminal hydroxyl groups (M-OH) and surface hydrogen atoms. The thermodynamic driving force of this process comes from the strong Lewis acidity of metal ions, making water molecules easy to dissociate. Both experiments and DFT calculations indicate that surfaces covered with low oxygen tend to dissociate and adsorb, while surfaces covered with high oxygen tend to adsorb molecules.
