Experimental Research On Synfnesis Of Aligned Carbon Nanotubes Arrays In Flame Pyrolysis

Carbon nanotubes (CNTs) have been showing an attractive prospects ofapplication, such as:hydrogen storage, field emission and nano-scale electronic devices,due to their outstanding electrical, chemical and physical properties.Aligned CNTs(ACNTs) arrays is a kind of orientationform of carbon nanorubes,which feature a much more concentrated growth density and neatly array, thus the ACNTs are of higher valuethan the mussy and circumvolute CNTs, specifically ACNTs areappiled as field emission cathode materials because of their unique property.Post-treatment methods were initially applied to prepare CNT arrays, but now it is the mainstream to producealigned CNTs via direct synthesis approachesas the technology develops.The mature ways to synthesize aligned CNT array requires the complicated reaction facilities and the relatively high cost. ACNTs have been previously been synthesized via V-shaped flame method under the influence of electrostatic field andthe outcome arrays are wellaligned and relatively good in morphology. This has thrown light upon new methods to continuously produce ACNTs at low cost easily. Additionally, flame pyrolysis method is found to be an effective and easy approach to produce CNTs. The quality of its production is even better than that of V-shaped flame method. This is mainly owing to the oxygen-free atmosphere where the CNTs grows in and the catalysis pattern of Fe/Mo/Al2O3carrier catalysts.Based on the approaches previously developed, the flame pyrolysis method is improved in this paper, in order to find out how to synthesize ACNTs in the pyrolysis chamber of the V-shaped experimental apparatus. The experiment put emphasis on improving the method to measure temperatureof pyrolysis flame and the ways to coat catalyst. These improvements contribute to the successful outcome which is better than what was produced by V-shaped flame synthesis with electrostatic field. Based on the flame pyrolysis synthesis, the approach was advanced with the introduction of electrostatic field and this results in outcomes of better quality. The amount of the bias voltage and the type of equipment to carry outcome were examined in the flame pyrolysis process with electrostatic field. Self-oriental CNTs grows along the electric field bystrong guiding effect of electrostatic field. The choice of equipment to carry outcome can leads to different result of synthesis. In the paper the growing mechanisms of ACNTs with and without electrostatics field is discussed respectively.