Origin of Giant Ionic Currents in Carbon Nanotube Channels

Journal Article · Sat Jan 01 04:00:00 EST 2011 · ACS Nano

DOI:https://doi.org/10.1021/nn202115s· OSTI ID:1036599

Pang, Pei ^[1]; Park, Jae Hyun nmn ^[2]; Krstic, Predrag S ^[2]; Lindsay, Stuart ^[1]; He, Jin ^[1]

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1. Arizona State University
2. ORNL

Fluid flow inside carbon nanotubes is remarkable: transport of water and gases is nearly frictionless, and the small channel size results in selective transport of ions. Very recently, devices have been fabricated in which one narrow single-walled carbon nanotube spans a barrier separating electrolyte reservoirs. Ion current through these devices is about 2 orders of magnitude larger than predicted from the bulk resistivity of the electrolyte. Electroosmosis can drive these large excess currents if the tube both is charged and transports anions or cations preferentially. By building a nanofluidic field-effect transistor with a gate electrode embedded in the fluid barrier, we show that the tube carries a negative charge and the excess current is carried by cations. The magnitude of the excess current and its control by a gate electrode are correctly predicted by the Poisson-Nernst-Planck-Stokes equations.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: DOE Office of Science; USDOE
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1036599
• Journal Information: ACS Nano, Journal Name: ACS Nano Journal Issue: 9 Vol. 5; ISSN 1936-0851
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ANIONS
CARBON
CATIONS
ELECTRODES
ELECTROLYTES
FIELD EFFECT TRANSISTORS
FLUID FLOW
GASES
NANOTUBES
ORIGIN
TRANSPORT
WATER