Synthesis of Nanorods within Porous Membranes

The first procedure reported for the production of metal nanorods is called template synthesis.This method entails the preparation or deposition of the desired material within the cylindrical and monodisperse pores of a nanopore membrane. Martin and coworkers used polycarbonate filters, prepared by the track-etch method, and nanopore aluminas prepared electrochemically from Al foil, as template materials. This method allows the preparation of cylindrical nanostructures with monodisperse diameters and lengths, and depending on the nature of the membrane and the synthetic method used, these may be solid nanowires or hollow nanotubes. 

A sequential electrodeposition within a porous template can be used to prepare striped nanowires with tailorable dimensions and composition. Variation in composition along the length of the wire can be used to incorporate electrical functionalities, optical contrast, and the desired surface chemistry.  

Although very uniform thickness and controlled length were achieved, the amounts that could be made following this procedure were always very small, but still considerable basic work on the optical properties and alignment of these rods could be achieved.  

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