Preparation And Characterization Of Nano-composites Based On Carbon Nanotubes

Carbon nanotubes have demonstrated a wealth of exceptional structure, mechanical and electronic properties, which have made them potentially useful for application in nano-composites. The hybrid materials based on carbon nanotubes have become an area of significant interest in recent years. In the presented paper, organic material and inorganic particles were respectively combined with multi-wall carbon nanotube to form novel nano-composites by various methods. The obtained composites were characterized using HRTEM, HRSEM, AFM and fluorescence spectrum.The soluble multi-wall carbon nanotube(MWNT) was prepared by acid-treatment. The acid-treated MWNT could be dispersed into water to form very stable aqueous colloids with the help of ultrasonication. The concentration of the obtained colloid solution could reach 0.5 mg/mL. The results revealed that the carboxylic acid groups were presented on the MWNT, which allowed the layer-by-layer self-assembly of polyelectrolyte/MWNT multilayer films. MWNT/[AlcianBlue8GX,AB] and MWNT/[Poly(ethyleneimine),PEI] multilayer composites were assembled onto substrates. Within MWNT/AB composites, AB molecules aggregated and charge-transfer might exist between AB molecules and the MWNT. For MWNT/PEI composites, MWNT uniformly covered the entire surface of the substrate. And the film thickness could reach 1 μm. The multilayer films could be peeled off from the substrates to form the free-standing MWNT/PEI membranes, which could serve as components for some optoelectrical devices.Nickel/phosphorus-layer was deposited on the chemically treated MWNT by an electroless plating. By acid treatment some functional groups were obtained on the surface of carbon nanotubes, and activated sites were formed on the surface of carbon nanotubes after sensitized and activated respectively in Sn and Pd solution subsequently. The results showed that Ni/P coatings could be dopoisted and formed on the surface of carbon nanotubes. The surface modification of the MWNT, activated sites and the plating time were the key to obtain continous layer. The Ni/P layerbecame crystalline from amorphous after heatreatment, and the heatment had influence on the magnetic properties of the coated MWNT.A method to surface coverage MWNT with titania nanoparticles in non-aqueous solution was proposed. The results indicated titania nanoparticles covalently attached onto MWNT in a reliable and robust manner. Both acid-treated MWNT and the coated MWNT exhibited luminescence and the luminescence from the composite was stronger than that from pure MWNT.