Nanocomposite Made By Carbon Nanotubes Paper And Cu Nanoparticles And Application Of Cu₂O Nanoparticles

Carbon -metal nancomposites has been widely applied in anti-abrasive material, absorbing, electronic packaging, super capacitor, lithium battery and heat dissipation material due to its large rigidity, high strength, light weight, small expansion coefficient, high heat radiation. Its strength and wear resistance increase is to 86 MPa and 1.5 ×10-4 g/m, respectively. The strength and abrasion resistance of CNTs reinforced Al composites generally be improved with the increase of amount of CNTs. If we can disperse the CNTs evenly and get a CNTs reinforced metal matrix composites with high CNTs proportion, the mechanical properties and thermal properties of the metal would be enhanced greatly. Agglomeration of CNTs will happen if the compound quantity of CNTs is too much in the CNTs reinforced metal composites. Usually, the metal and CNTs are mixed adequately by powder metallurgy. When the amount of CNTs is up to 5vol.%(reported in literature), uniform dispersion of CNTs is difficult due to the considerable density difference between CNTs and metal particles, which will lead to the reduction of the mechanical properties of CNTs/metal composite. So how to get a CNTs/metal composite with high CNTs proportion is a technical difficulty.Carbon nanotubes paper (CNP) is a kind of paper material which is made from the uniform dispersed CNTs and Carbon nanofibers. The CNP unfolds 3D porous network, whose electronic conductivity, thermal conductivity and gap generally with 100 nm to 2μm is adjustable. The CNP has been used in lithium ion batteries and fuel cells. Besides, CNP/organic polymer composite is adopted in electromagnetic shielding, heat conduction membrane, shockproof device and body armor. The porosity of CNP provides effective interspace for the infilling of other substances. If we can fill the gap of CNP with functional metal materials, a new type of super light metal composite with high thermal conductivity would be prepared.In addition, the uniform dispersion of CNTs is not a problem upon the compounding with metal. However, the problem of effective combination between metal and CNP must be solved,In this work, we fill Cu nanoparticles into the gap of CNP that was made from CNFs and followed by post-sintering, forming Cu-CNP composite. We further optimize the performance of CNP-metal composite by changing the size of Cu nanoparticles and realizing the functionalization of CNFs. In order to prepare CNP-Cu composite with high thermal conductivity, Cu nanoparticles (average size is 11 nm) synthesized by chemical reduction method were filled into the gap of a new type of modified CNP. We conducted the following three parts:(1) We prepared small sized Cu nanoparticles by chemical reduction. Then, the optical properties and energy band of Cu nanoparticles are analyzed. It is concluded that the prepared Cu nanoparticles have shown the semiconductor properties owing to quantum size effect; (2) The relationship between different electroplating conditions and morphologies of electro-plated Cu nanoparticles are discussed. When the electroplating current density is 3.73 mA/cm2, Cu particle deposited on concentrated acid treated CNP was small and evenly dispersed; (3) A layered structured cooling fin was fabricated using modify CNP as a substrate and Cu nanoparticle as filler by powder metallurgy method. The radiator consisted of two layers:one layer of pure copper as thermal and electric conductive layer; another layer of CNP-copper composite as cooling fin. The conductivity of CNP/Cu cooling fin layer is five orders of magnitude higher than that of pure CNP; It shows that copper-CNP composite cooling fin exhibits better heat dissipation performance compared to pure copper layer.In addition, we discuss the preparation of Cu2O nanoparticles by direct oxidation of Cu nanoparticles. As the expansion content, these Cu2O nanoparticles are utilized as active electrode materials in lithium-ion batteries. The optical performance and energy band of Cu2O nanoparticles were also analyzed. The results indicate that the energy band of Cu2O nanoparticles is slightly higher than that of bulky Cu2O due to the quantum confined effect. When used as anode active materials in LIBs, the specific capacity of nanostructured Cu2O maintained at 236.7 mAh g-1 after 50 cycles.