Thermal Oxidation Kinetic of Carbon Nanotubes (CNTs)

Aligned multi-wall carbon nanotubes (CNTs) were synthesized by a catalytic cracking chemical vapor deposition (CC-CVD) method. The effects of hydrogen flow rates and hydrocarbon amounts were studied to selectively synthesize carbon nanomaterials at high yield, high purity, and high quantity. Iron nanoparticles that were produced from the thermal decomposition of iron oxide on the surface of aluminum oxide powder were used as a catalyst for the synthesis of the carbon structures. The effects of different hydrogen flow rates (10-700 ml/min) and the amount of ethylene gas (50-700 ml/min) on the morphology, quality and quantity of the product were investigated. The thermal oxidation kinetics of CNTs was investigated by dynamic thermogravimetry, in an air atmosphere, over the temperature range 25-800 °C and at constant nominal heating rate 10 °C/min. The corresponding activation energies, frequency factors, and reaction orders were determined.