Voltage Gated Carbon Nanotube Membranes

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• 作者：Mainak Majumder ; Xin Zhan ; Rodney Andrews ; Bruce J. Hinds
• 刊名：Langmuir
• 出版年：2007
• 出版时间：July 31, 2007
• 年：2007
• 卷：23
• 期：16
• 页码：8624 - 8631
• 全文大小：321K
• 年卷期：v.23,no.16(July 31, 2007)
• ISSN：1520-5827

文摘

Membranes composed of an array of aligned carbon nanotubes, functionalized with charged molecular tethers, showvoltage gated control of ionic transport through the cores of carbon nanotubes. The functional density of tethered chargemolecules is substantially increased by the use of electrochemical grafting of diazonium salts. Functionality can beforced to occur at the CNT tip entrances by fast fluid flow of an inert solvent through the core during electrochemicalfunctionalization. The selectivity between Ru(bi-pyridine)₃²⁺ and methyl viologen²⁺ flux is found to be as high as23 with -130 mV bias applied to the membrane as the working electrode. Changes in the flux and selectivity supporta model where charged tethered molecules at the tips are drawn into the CNT core at positive bias. For moleculesgrafted along the CNT core, negative bias extends the tethered molecules into the core. Electrostatically actuatedtethers induce steric hindrance in the CNT core to mimic voltage gated ion channels in a robust large area platform.