Abstract
Catalytic chemical vapor deposition is one of the most promising synthetic route for production of large quantities of carbon nanotubes economically. The first part of this thesis is to produce carbon nanotubes by floating catalyst method. The precursor is vaporized at 150 oC, and then catalystically decomposed at 900 oC to produce carbon nanotubes. This method can produce carbon nanotubes of higher purity and yields than other traditional methods. The second part of this thesis is to rapidly surface-functionalized multi-walled carbon nanotubes in an one pot process by using microwave induced radical polymerization reaction. Both hydrophobic (e.g., polystyrene, polyglycidyl methacrylate, polyethylene glycol methacrylate phosphate, polyvinyl acetate, poly-4-vinyl phenylboronic acid, etc), and hydrophilic (e.g., poly-2-acryl amido-2-methylpropanesulfonic acid, etc), polymer chains can be chemically grafted onto the surface of MWNT by the same process within 10 min. The surface grafted polymers were identified by various spectroscopic methods, such as, FTIR, NMR, TGA, TEM, Raman spectra and EELS spectra. The solubilities of the surface derivatized MWNTs are in the range of 900~2400 mg/L in solution. The third part of this thesis is to investigate the influence of surface functionlization of carbon nanotubes on the interfacial interactions between the polymer matrix and carbon nanotubes. The enhanced storage modulus of epoxy resin filled with 2% CNT-PAA-DETA is two times that of epoxy resin filled with 2%CNT-COOH -DETA. The enhanced storage modulus of epoxy resin with 2%CNT-PAA-DETA at 100 oC is 2.4 times higher than that observed at 30oC. The enhanced load transfer efficiency at high temperature is attributed to formation of convalent bonds between CNTs and the epoxy resin matrix.