Views: 0 Author: Site Editor Publish Time: 2023-01-12 Origin: Site
Melting point: 1083℃
Boiling point: about 2500℃.
Copper powder can be dissolved in nitric acid and hot concentrated sulfuric acid, slightly soluble in hydrochloric acid. Copper heated in oxygen can react with oxygen to produce copper oxide, but not combustion, exactly redox reaction. Pure copper is rose-red, metallic luster, but oxidation formed after the formation of oxide film, the appearance of purple, so usually called purple copper.
Copper powder has good electrical conductivity, thermal conductivity, widely used in conductive materials and heat transfer materials toughness and wear resistance.
1). Electrical pastes
Traditional MLCC (Multilayer Ceramic Capacitor) inner and outer electrodes are made with precious metals. With the rising price of precious metals and decreasing profit of MLCC, multilayer ceramic capacitors with base metal electrodes have become a more economical alternative to traditional precious metal electrode designs. Nano copper powder with copper electronic paste can be sintered to produce electrodes only 1 micron thick, which can optimize the microelectronic process, meet the miniaturization requirements of MLCC devices, replace the precious metal electronic paste such as silver power, and significantly reduce the price cost. Micro and nano metal powders (palladium, silver, nickel, copper, etc.) account for more than 5% of the structural cost of MLCCs (5% in low-capacity MLCCs and 5%-10% in high-capacity MLCCs). In order to meet the trend of cost reduction and lightweight development direction of MLCC in recent years, the market scale and development potential of monodisperse micro-nano copper powder as an important alternative material to the aforementioned micro-nano metal powders (palladium, silver, nickel) is huge, but also the specifications of the micro-nano copper powder used are further enhanced. MLCC with an inner electrode thickness of 2-3 µm requires metal crystals with a spherical or nearly spherical shape, particle size control below the micron level, preferably 0.2-0.7 µm, and uniform distribution.
In addition, metal materials due to small particle size, low sintering temperature and other excellent characteristics, and made of conductive ink is easy and widely used in the field of printed electronics. The ideal state of metallic conductive inks should be easy to make, store and inkjet, and the conductivity and price should be fully considered. Considering all factors, copper nanoparticles are the most promising metals for the preparation of conductive inks for popular applications. Copper nanoconductive inks are mainly used in two fields: printed circuits and display products.
2). Solid lubricants
The use of copper nanopowders as solid lubricants is one of the examples of nanomaterial applications. Ultra-fine copper powder dispersed in a suitable manner in various lubricants can form a stable suspension, which contains millions of ultra-fine metal powder particles per liter, which combine with the solid surface to form a smooth protective layer while filling micro-scratches, thus significantly reducing friction and wear, especially under heavy load, low speed and high temperature vibration conditions.
3). Highly efficient catalysts
Micro- and nano-scale copper powder has relatively large specific surface area and high surface activity, which can be used as catalysts in metallurgical and petrochemical fields to catalyze many organic reactions and exhibit high catalytic activity. For example, micro-nano copper powder can also catalyze acetylene polymerization in the process of making conductive fibers, and partially replace precious metals platinum and ruthenium in the process of automobile exhaust treatment to complete the conversion of polluting CO to CO2 in exhaust gas.
4). High performance engineering materials
Nano copper powder is the basic raw material for the preparation of nano-crystalline copper materials. Compared with general coarse crystalline copper, nano-copper powder has higher hardness, tensile strength and thermal conductivity. High density and high purity nano-copper has good superplastic ductility and can be widely used in the field of engineering materials.
5). Antibacterial materials
In terms of antimicrobial properties, researchers have compared the antimicrobial properties of copper nanoparticles and silver nanoparticles against different strains of bacteria and found that they have different strengths and weaknesses for different strains of bacteria.
Overall, metallic copper showed strong antimicrobial properties with high chemical stability and environmental safety and relatively low price, so the antimicrobial properties of copper nanoparticles can be effectively utilized.