Liquefied petroleum gas (LPG), a cheap industrial material, is used as carbon source to produce carbon nanotube (CNT) arrays on ceramic spherical surface on a large scale in the floating catalyst process. The ceramic ...Liquefied petroleum gas (LPG), a cheap industrial material, is used as carbon source to produce carbon nanotube (CNT) arrays on ceramic spherical surface on a large scale in the floating catalyst process. The ceramic spheres provide huge surface area and good mobility, leading to the mass production of CNT arrays continuously. The arrays obtained from the surface are of good alignment, and the purity is as high as 97.5%. With the decrease of the growth temperature, CNTs in the array form with small-diameter of about 13 nm can be obtained. Therefore, with the industrial fuel as carbon source and the ceramic sphere as substrate, CNT arrays can easily be produced on large scale at low cost.展开更多
Electric discharge has been carried out in LPG using DC high voltage (0.4 - 3 KV) at gas pressure in the range of 1 to 25 torr. The electric and spectroscopic characteristics of the discharge were studied at different...Electric discharge has been carried out in LPG using DC high voltage (0.4 - 3 KV) at gas pressure in the range of 1 to 25 torr. The electric and spectroscopic characteristics of the discharge were studied at different discharge conditions. Deviations from Paschen’s law were observed as a result of the change of the distance between the two the electrodes. Two discharge modes, namely glow discharge and spark discharge modes, has been observed in the discharge current waveforms. The discharge current waveforms indicate a repetitive pulsed behaviour with frequencies of 5 kHz to 5 MHz depending upon the applied voltage and the gas pressure. The emitted spectra from the discharge are also studied near both the cathode and the anode using different electrode materials. Hα line and C2 Swan band system are observed, which confirms the conversion of LPG to hydrogen and carbon clusters.展开更多
基金Supported by the Foundation for the Authors of National Excellent Doctoral Disser-tations of China (Grant No. 200548)the National Natural Science Foundation of China (Grant No. 20606020)+1 种基金the National Basic Research Program of China (Grant No. 2006CB0N0702)the Key Project of the Ministry of Education of China (Grant No. 106011)
文摘Liquefied petroleum gas (LPG), a cheap industrial material, is used as carbon source to produce carbon nanotube (CNT) arrays on ceramic spherical surface on a large scale in the floating catalyst process. The ceramic spheres provide huge surface area and good mobility, leading to the mass production of CNT arrays continuously. The arrays obtained from the surface are of good alignment, and the purity is as high as 97.5%. With the decrease of the growth temperature, CNTs in the array form with small-diameter of about 13 nm can be obtained. Therefore, with the industrial fuel as carbon source and the ceramic sphere as substrate, CNT arrays can easily be produced on large scale at low cost.
文摘Electric discharge has been carried out in LPG using DC high voltage (0.4 - 3 KV) at gas pressure in the range of 1 to 25 torr. The electric and spectroscopic characteristics of the discharge were studied at different discharge conditions. Deviations from Paschen’s law were observed as a result of the change of the distance between the two the electrodes. Two discharge modes, namely glow discharge and spark discharge modes, has been observed in the discharge current waveforms. The discharge current waveforms indicate a repetitive pulsed behaviour with frequencies of 5 kHz to 5 MHz depending upon the applied voltage and the gas pressure. The emitted spectra from the discharge are also studied near both the cathode and the anode using different electrode materials. Hα line and C2 Swan band system are observed, which confirms the conversion of LPG to hydrogen and carbon clusters.
