Study On The Synthesis Of Hydroxylation Carbon Nanotubes/Polysilanes Composite Materials

With its unique structure, carbon nanotubes have special properties in mechanics, electrology and optics, therefore, it has been used in the field of medicines, materials, devices and biology extensively. Depending on the ? delocalization and diversified structures, the conductivity of carbon nanotubes varied between the insulator and the metal. Polysilanes are formed by ? bond which can extensively delocalize along the main chain, and form a large conjugated system which is similar to ? conjugation. In this paper, hydroxylated carbon nanotubes combine with polysilanes by organic methods. It not only gets a new kind of composite materia, but also improves the conductive properties of the polysilanes.This paper uses the method of Grafting-From to graft the polysilanes onto carbon nanotubes. Firstly, carbon nanotubes are purified by means of calcination treatment, nitric acid treatment and hydrochloric acid treatment. Secondly, hydroxylation carbon nanotubes are obtained through nitric acidification method, potassium permanganate oxidation and Fenton reagent oxidation method. Finally, the hydroxylation carbon nanotubes react with three kinds of silane monomers, and get the carbon nanotubes grafted with silane monomers. Then the products graft with silane monomer via Wutrz reaction to get polysilanes/carbon nanotubes complexes. Through amount of experiments and analysis of scanning electron microscopy, infrared spectroscopy, thermal gravimetry analysis, transmission electron microscopy and energy spectrum, it gets the optimal experimental program.The results show that the best method of hydroxylating carbon nanotubes is Fenton reagent oxidation:according to the molar-ratio of M(H2O2):M(Fe2+)=40, reaction lasts 6 hours at room temperature. The silane monomer could be grafted to the hydroxylation carbon nanotubes when using DMF as solvent and pyridine as catalyst; the composite materials of hydroxylation carbon nanotubes/ polysilanes can be synthesized via Wurtz reaction, the reaction is executed under the conditions of N2 gas protection, anhydrous circumstance and no light. The conductivity experiments prove that the conductivity of the polysilanes which modified by carbon nanotubes are improved better.