Single carbon nanotube membranes: A well-defined model for studying mass transport through nanoporous materials

This work represents the first study of mass transport phenomena within a nanotube and thus holds promise as; a means of probing the properties of nanotube interiors. Multiwall carbon nanotubes are used as templates to fabricate single-pore membranes. These membranes are better experimental models for testing specific predictions of mass transport theories than arrays of nanopores because they require fewer adjustable parameters and they have well-defined geometry and chemical structures. Using polystyrene particles as probes, we demonstrate that quantitative information about fundamental modes of transport, such as hydrodynamic and electrophoretic flow, can be obtained using these single-pore membranes. Furthermore, time-resolved mass transport measurements can be achieved when the method of Coulter counting is used.