Core−Shell and Segmented Polymer−Metal Composite Nanostructures

Composite nanostructures (∼200 nm wide and several micrometers long) of metal and polyaniline (PANI) in two new variations of core−shell (PANI−Au) and segmented (Au−PANI and Ni−Au−PANI) architectures were fabricated electrochemically within anodized aluminum oxide (AAO) membranes. Control over the structure of these composites (including the length of the gold shells in the core−shell structures) was accomplished by adjusting the time and rate of electrodeposition and the pH of the solution from which the materials were grown. Exposure of the core−shell structures to oxygen plasma removed the PANI and yielded aligned gold nanotubes. In the segmented structures, a self-assembled monolayer (SAM) of thioaniline nucleated the growth of PANI on top of metal nanorods and acted as an adhesion layer between the metal and PANI components.