摘要
The microstructural evolution and oxidation resistance of multi-walled carbon nanotubes （MWCNTs） by di- rectly heating silicon powder and MWCNTs in a coke bed from 1000 to 1500 ~C are investigated with the aid of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM） and thermogravimetry-differential scanning calorimetry （TG-DSC）. The results showed that the morphology and microstructure of MWCNTs did not change much after being treated from 1000 ~C to 1200 ~C. An obvious SiC coating was formed on the surface of MWCNTs from 1300 to 1400 ~C. Up to 1500 ~C, nearly all the MWCNTs transformed into SiC nanowires. The oxidation resistance of the treated MWCNTs was improved compared with as-received ones. Non-isothermal kinetics showed that the oxidation activation energy of the treated MWCNTs reached 208 kJ/mol, much higher than 264 k J/tool of as-received ones.
The microstructural evolution and oxidation resistance of multi-walled carbon nanotubes （MWCNTs） by di- rectly heating silicon powder and MWCNTs in a coke bed from 1000 to 1500 ~C are investigated with the aid of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, high resolution transmission electron microscopy （HRTEM） and thermogravimetry-differential scanning calorimetry （TG-DSC）. The results showed that the morphology and microstructure of MWCNTs did not change much after being treated from 1000 ~C to 1200 ~C. An obvious SiC coating was formed on the surface of MWCNTs from 1300 to 1400 ~C. Up to 1500 ~C, nearly all the MWCNTs transformed into SiC nanowires. The oxidation resistance of the treated MWCNTs was improved compared with as-received ones. Non-isothermal kinetics showed that the oxidation activation energy of the treated MWCNTs reached 208 kJ/mol, much higher than 264 k J/tool of as-received ones.
基金
supported by the Natural Science Foundation of Hubei Province (No.2009CDA050)
the New Century Excellent Talents in University (No. NCET-10-0137)
the National Natural Science Foundation of China (No. 51072143)
