Modification Of Carbon Nanotubes And Study The Functional Materials

Carbon nanotubes(CNTs) have attracted great attention because of their unique structural,electronic,mechanical and thermal properties.CNTs consist of graphitic sheets,which have been rolled up into a cylindrical shape.The length of CNTs is in the size of micrometers with diameters up to 100 nm.Because of their extraordinary properties,CNTs can be considered as attractive candidates in diverse nanotechnological applications,such as fillers in polymer matrixes,electronics,,and many others.However,the lack of solubility and the difficult manipulation in any solvents have imposed great limitations to the use of CNTs,which form bundles, which are entangled together in the solid state,giving rise to a highly complex network.To address this problem,current work is in progress on modification of CNTs with two ways:(a) the covalent attachment of chemical groups through reactions onto theÏ€-conjugated skeleton of CNTs;(b) the noncovalent adsorption or wrapping of various Functional molecules.This paper reports a method of preparing amino-functionalized muti-walled carbn nanotubes(MWCNTs).First,the amorphous carbon is eliminated with high temperature to purify the MWCNTs,then the purified carbon nanotubes is oxidized with mixture of H₂SO₄(98%)/HNO₃(68%)(3:1 v/v),carboxylated MWNTs is treated with thionyl chloride.In the end,the acylated MWCNTs without drying reacts respectively with 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, 4",4"'-(Hexafluoroisopropylidene)-bis(4-phenoxyaniline),and 4,4'-diaminodiphenyl sulphone.Many literatures reported just enhance the dispersion of carbon nanotubes in complex,while the functionalized carbon nanotubes were only blended in the complex.However,amino-functionalized carbon nanotubes papers published concerned about the amines with low molecular weight,which have higher reactivity and could attach to the carbon nanotubes easier.In this paper,the study was focused on the functionalization of carbon nanotubes covalently bonded with reactant,which can be used as curing agent and end-blocking agent in polymer such as polyimide. Being more sterically hindered and with more complex structure,it's difficult to bond the amines to the carbon nanotubes.And we also prepared the composites of silicone reinforced with amino-functionalized multi-walled carbon nanotubes.FT-IR,Raman, EDX,XRD,SEM,and TGA were employed to investigate and determine the chemical structure and texture of the amino-functionalized MWNTs.TGA,DSC and universal tester were used to estimate the thermo-physical properties of the composites.We also prepared the thermal conductive materials too,and the property of the thermal conductive materials was studied.