Montmorillonite–carbon nanotube nanofillers by acetylene decomposition using catalytic CVD

Abstract Montmorillonite–carbon nanotube nanofillers (a binary hybrid material) were successfully synthesised for polymer reinforcing applications. Montmorillonite (Mt) supported iron oxide (20 and 25 wt.%) catalysts were prepared using the conventional wet impregnation method and calcined at 450 °C. In situ reduction of the catalysts and synthesis of CNT was carried out in a horizontal furnace at 750 °C using acetylene along with nitrogen and hydrogen. The influence of gas composition on the carbon nanotube growth characteristics of montmorillonite supported iron oxide catalysts was studied. Growth experiments with two different gas compositions containing 5 and 8 vol.% of acetylene were used to evaluate the effect of the concentration of acetylene gas on the yield, morphology and purity of the carbon nanotubes over each catalyst. Highly selective, crystalline and defect free carbon nanotubes were obtained at low acetylene concentration in the total gas flow.