Transport properties of template-synthesized gold and carbon nanotube membranes

摘要

We discuss the fabrication of gold and carbon nanotubes prepared by the template method. The gold nanotubes are prepared via electroless deposition of Au onto the pore walls of a nanoporous polycarbonate filtration membrane. Carbon nanotube membranes (CNMs) are prepared by doing chemical vapor deposition of carbon within the pores of a microporous alumina template. The pores in these filtration membranes act as templates for the nanotubes. We have shown that by controlling the Au deposition time, Au nanotubes that have effective inside diameters of molecular dimensions (< 1 nm) can be prepared. These membranes are a new class of molecular sieves and can be used to separate molecules based on size. Furthermore, we describe fundamental investigations of electroosmotic flow (EOF) in carbon nanotube membranes. In addition, an electrochemical derivatization method was used to attach carboxylate groups to the nanotube walls; this enhances the anionic surface charge density, resulting in a corresponding increase in the EOF rate in the CNM.