Modification Of Carbon Nanotubes And Adsorption Properties

As one of the perfect one-dimensional nano-materials, carbon nanotube has porous microstructure with high area and energy, which makes it a promising gas sensing material. Some report suggested that CNT could enhance electro-transfer of adsorption biology molecule greatly, so it can become a kind of potential material for biology sensor. This paper studies the chemical and optic influence of chemically treated of carbon nanotube films in experiment, and emphasizes the electric mechanism and Raman spectrum effects of the CNTs after glycine and cholesterol adsorbed treatment.Carbon nanotubes , synthesized by pyrolysis of xylene., studied by SEM, TEM and Raman spectroscopy. Based on the above studies, The chemical modification of carbon nanotubes was carried out using the mixture of oil of vitriol and nitric acid treatment methods. These modified carbon nanotubes were characterized by TEM image,FTIR spectra and Raman spectroscopy. The result find the end of Cabon nanotubes was unclosed and become carboxyl-treated Carbon nanotubes because of engaging the carboxyl. Multi-wall carbon nanotubes by using screen print was spread on the interdigitated Ag electrodes, which was splashed by magnetron sputtering. Through the V-I curves experiment and the four-probe experiment, we tested The electrical conductivity of the dried carbon nanotubes films. Film resistances both treated and untreated carbon nanotubes were studied,respectively. The results showed that film resistances of treated carbon nanotubes largen. Deposited time of treated carbon nanotubes effects on resistance were explored as well. Film resistances increased rapidly at the beginning stage, and slowly increased before reduction, moved toward stability with the passage of time.The electrical conductivity of the dried carbon nanotubes film increased when the electrode was exposed to glycin, and the increasing amplitude of conductivity is associated with the glycin concentration. The mechanism that the conductivity of carbon nanotube films changes when glycin is absorbed is discussed preliminary. Raman Spectral analyses present a contrast between carbon nanotube films which the electrode was exposed to glycin and untreated ones. The result show that the I_D/I_G is 0.6804 and 0.8958 of carbon nanotubes before and after glycine adsorption, respectively.Moreover, both D band and G band have undergone varying degrees of frequency shift.This Experimental result indicates that multi-wall cabon nanotubes is a promising sensing material for glycin detection at room temperature.The electrical conductivity of the dried carbon nanotubes film decreased when the electrode was exposed to cholesterol, and the decreasing amplitude of conductivity is concerned with the cholesterol concentration. Electronic properties about carbon nanotube films after cholesterol adsorbed treatment were theoretically analyzed. Raman Spectral analyses present a contrast between carbon nanotube films which the electrode was exposed to cholesterol and untreated ones. Structural defects and Cholesterol absorption of defects because of Structural defects Make changes Raman spectroscopy of carbon nanotubes.