Research Of Carbon Nanotubes With Electroless Plating Of Cobalt

The discovery of carbon nanotubes has given rise to many scientists widely attention around the world,which exhibit excellent mechanical properties,electrical properties,the unique micro-structure,high aspect ratio and high specific surface area,,carbon nanotubes(CNT) have many potential applications in various fields.However,carbon nanotubes which have many defects and relatively poor dispersion,in particular,the structure of carbon nanotubes on the surface tend to affect the electrical/mechanical and optical performance and so on.As a result,improve the surface structure of carbon nanotubes,strengthen the humid of carbon nanotubes and medium,how to disperse the carbon nanotubes in medium and so on,this researchs have given rise to people' s interest.This study used Electroless plating process coating cobalt metal layer on the surface of carbon nanotube,the carbon nanotubes with cobalt metal layer can improve the structure and properties of carbon nanotubes, to enhance the carbon nanotubes and metal,ceramics,polymers,such as the medium material bonding interface,which is the main methods to expansion of carbon nanotube' s Application and use of carbon nanotube' s excellent capability.This study prepared multi-walled carbon nanotubes as a target plating which produced by CVD,a series of purify treatment brfore the Electroless plating, microwave,NaOH,nitric acid,and then used the purification' s carbon nanotubes in the SnCl₂ solution to carry out sensitization,in the PdCl₂ solution to carry out activation.the next to Electroless plating.A series of cobalt deposits was coated On the surface of carbon nanotubes.And use of infrared spectroscopy(IR).transmission electron microscopy(TEM).spectroscopy(EDS).X-ray diffraction(XRD) analysis and other modern means to studied the micro-structure of carbon nanotubes coated.The results showed:Microwave processing of carbon nanotubes can elimination of amorphous carbon nanotubes to improve the crystallinity;and then used NaOH solution to proceed further purification,except the main components of impurities,such as SiO₂ which bring by prepared carbon nanotubes by CVD process used in the catalyst support,and then treated with carbon nanotubes concentrated by HNO₃,further purification and improve it' s performance on the surface,graft functional groups,infrared spectroscopy showed that after dealing with concentrated nitric acid,a large number of functional groups graft ed on the surface of carbon nanotubes:carbonyl(>C=O),hydroxyl(-OH),carboxyl(-COOH),and so on.And then with the purification of carbon nanotubes carry out sensitization in the SnCl₂ solution and carry out activation in PdCl₂ solution using ultrasound method.So that the surface of carbon nanotubes can be activated,As much as possible' s activated will be beneficial that cobalt metal coats carbon nanotubes on the surface,and can obtain a row of cobalt metal coating,to improve the quality of electroless plating. Electroless plating was operated under the constant temperature and mixing,and adjust many factors:compound,temperature,pH valve,time and so on,and obtained a complete,uniform,dense coating of cobalt metal on the surface of carbon nanotubes.Through TEM.EDS and XRD analysis showed that orthogonal program 7, plating conditions are as follows:at the temperature is 45℃and pH is 10,with the (COSO₄·7H₂O 25g)as the main salt and(NaH₂PO₂·7H₂O 30g) as the reducer, (Pb(NO₃)₂ 4.5×10^-2g) as the stabilizer and((NH₄)₃C₆H₅O₇24g) as the complexing agent.With this program,A series of cobalt metal coated on the carbon nanotube' s surface,and obtained uniform.continuous coating.