The Process Of Electroless Copper Plating On CaCO₃/SiO₂ Powder And Study On Attenuation Effect

Composites are potential components for a wide range of applications including component for the automotive and aerospace industries, electromagnetic interference shielding, cutting tools, reinforced electrodes and coatings. In this paper, Cu@SiC>2 andCu@CaCO3 in application of smoke agent is studied.First, the calcium carbonate are surface modificated with sodium stearate, then adhere on a layer of silver on the CaCO3 surface to have the activation center, then copper-coated CaCO3 powder composites are prepared. The structures of the composites are characterized by XRD and SEM. The result shows sodium stearate can be used to modify calcium carbonate, the best condition are:sodium stearate amount is 3%, modification temperature is 95℃, modification time is 50 min. The technology of electroless copper plating on CaCO3 surface was optimized.Second, a new approach for fabricating copper coated silica by a silane-terminated coating and subsequent electroless plating is reported. Silane covalently binds to the particle surface via hydrolysis and condensation reactions, and plated copper by chemical method. Characterized by XRD and SEM, proved that metal coated nanoparticles synthesized with this procedure show a uniform and conformal coating. Silane coupling agent to the particle surface via hydrolysis and condensation reactions, while the amino group promotes a selective metal deposition during the electroless plating process due to its high affinity towards metal ions. Moreover, no further activation and sensitization steps with palladium-based solutions are required, thus overcoming the high costs and complexity of the state of the art metallization procedures. Metal coated nanoparticles synthesized with this procedure show a uniform and conformal coating and are particularly well suited for the production of metal matrix composites.Smoke agent is prepared using two methods above composite as additive. Extinction performance are texted by FTIR. The preparation and capacity of the smokescreen materials against infrared are studied in the dissertation. The result shows that the duration is long of the composite powder sreen compares with before. The copper-coated CaCO3 powder has execellent attenuation performance.