Research On Modification Of Carbon Nanotubes And Grafting Of Ploysilanes

Carbon nanotubes is discovered by Japanese scientist Iijima in 1991 for the first time.Because of the unique electrical,optical,mechanics,and mechanical property,it has became a hot topic in the field of nanomaterials.Depending onπ delocalization,it will be an ideal one-dimensional quantum wire which behaves metal or semiconductor type.Depending on a delocalization,the polysilanes has better stability.With the combination of polysilane and carbon nanotubes,having the purpose of configuring π-π delocalized structure,it will make an important contribution to the development of new conductive polymer materials,and also have very important research value.In this paper,the polysilanes will be grafted onto modified carbon nanotubes with the method of Grafting-From.At first,strong acid oxidizes carbon nanotubes and produce carboxyl groups.Then graft with a functional group of πelectron system by the method of chloride and dehydration condensation,in order to get the amidated carbon nanotubes.Finally,three types monomer of dichlorosilane can be grafted onto the amidated carbon nanotubes,and then synthesize the polysilanes/carbon nanotube complexes.The products have been characterized through the infrared spectroscopy(IR),thermal gravimetry analysis(TGA),scanning electron microscopy(SEM)and transmission electron microscopy(TEM).The results show that:concentration of 7.5mol/L.dilute nitric acid oxidation of the carbon nanotubes best,the carbontube is preferably in the degree of dispersion in water and precipitation time,less damage to the structure of the carbon nanotube itself,and also produce more carboxyl group.During the reaction of grafting aminophenol,the acid chloride method will graft the amino group and hydroxyl group onto carbon nanotubes at the same time,while the method of dehydration condensation will graft the amino group onto carbon nanotubes directly.Under the condition of nitrogen,DMF as the solvent of silane monomer,a small amount of pyridine as the catalyst of reaction,different kinds of silane monomer can be grafted onto the amidated carbon nanotubes.Finally,the sodium as a condensing agent,with the condition of toluene boiling,reversing drop the silane monomer,the polysilane/carbon nanotube complexes can be produced by Wurtz reaction.