Color Synergistic Mechanism Of Carbon Nanotubes Applications

Studies on carbon nanotubes(CNTs) become a hot topic in the world due to the unique one-dimensional tubular structure and subtle physical and chemical properties.In this paper,a novel application of carbon nanotubes(CNTs) in the field of chromogenic reaction is described.The sensitization of CNTs as a new additive was studied in the chromogenic reaction of manganese with fluorone.The main achievements obtained in this research include:1.A new chromogenic system for the determination of manganese with fluorone in the present of CNTs has been developed and the mechanism was discussed.The paper studied the chromogenic reaction of the manganese with phenyl fluorone(PF) by the addition of CNTs and carboxylic CNT(c-CNTs),respectively. Comparative experiments proved that the absorption of the complex raised 45.3% in the presence of CNTs,higher than that of c-CNTs(26.8%).When CNTs were oxidized by the acids,the conjugated systems on the tops or the bending points were broken,so the electrons could not flow freely as before,and when noncovalented with fluorone,the conjugative systems could not be enlarged effectively.As a result,c-CNTs increased the absorption less than that of CNTs.Furthermore,the paper studied the chromogenic system of the manganese with 2,3,7-trihydroxy-9-(3,5-dibromo-4-hydroxyphenyl) fluorone(DBH-PF) and 2,3,7-trihydroxy-9-(3,5-dibromo-2-nitrylphenyl) fluorone(DBON-PF) by the addition of CNTs,and studied the influence of steric effect.The existence of CNTs could increase the absorbency of fluorones complex systems all,but the increasing percentages were different from each other.The order was,PF-Mn-CNTs＞DBH-PF-Mn-CNTs＞DBON-PF-Mn-CNTs.Comparing with PF,as the auxochrome,two bromines and one hydroxyl group exist on DBH-PF,while two bromines and one nitryl on DBON-PF.But they were the steric hindrance when CNTs were added in the system.While there were no such groups on PF and that allowed the PF to become closer to CNTs and made the delocalization much adequate as well,so the absorbency of Mn-PF-CTMAB-CNTs complex system raised mostly. 2.The recognition and selective determination were taken for aminophenol isomers in the CNTs analytical system.The paper studied the chromogenic reaction of the PAP by the addition of CNTs.The sensitivity and stability of the complex were discussed.PAP was the only absorbency system among the three aminophenol isomers(PAP,OAP,MAP), so the selective determination of PAP was obtained in the chromogenic reaction.The recognition and electrocatalysis of aminophenol isomers were studied on the carbon nanotubes modified electrode(CNTs/GE).The result shows that the current increased significantly and the oxidation peaks could be separated completely for PAP from the mixed aminophenol isomers(PAP,OAP,MAP) on CNTs/GE.So the selective determination of PAP was obtained at CNTs/GE successfully.