Polyaniline nanostructure electrode: morphological control by a hybrid template

Abstract

We report here a novel approach to the templateassisted electrochemical synthesis of vertically aligned polyaniline (PANI) nanostructure surface arrays. When PANI is obtained by electropolymerization inside a custommade anodic aluminum oxide (AAO) template, with an Au layer sputtered onto one side of the AAO acting as an anode, PANI nanotubes are obtained. In contrast, when the surface of this gold layer is modified with 4-aminothiophenol (4-ATP) as a self-assembled monolayer (SAM) film anchored to the gold layer via the thiol groups and on the opposite end having NH 2 functionalities, we obtain a surface array of PANI nanowires. Cyclic voltammetry and SEM analysis show that the amino functionalities of Au/SAMs act as a nucleation site in the internal base of the AAO pore and determine both the morphology and structure of polyaniline and its electronic properties as well.

Advances in Polyaniline for Biomedical Applications

“…In both cases the polymer growths on the surface of the template that at the end of the reaction is removed or destroyed. Among the templates, metal oxides [110][111][112] and organic polymers are the most employed [113]. This approach is cheap, easy and the templates commonly employed are inexpensive.…”

Vertically Aligned and Ordered One-Dimensional Mesoscale Polyaniline

“…The most regular PANI nanowire arrays are produced by the template route using either hard templates, such as particle track-etched membranes , or anodized aluminum oxide membranes, , or soft templates, such as block copolymer assemblies or self-assembled surfactant phases, , associated with electroless polymerization or electrochemical growth. Template synthesis provides a route of reproducibly and predictably controlling the morphology (diameter, length) and geometry (e.g., vertical alignment) of conjugated polymer films as they are endowed by the template itself.…”

“…23,24 Such 1D PANI nanostructures or nanocomposites are attractive for applications in various fields, including energy, 17,19,23,25−28 sensors and biosensors, 9,29,30 photovoltaics, 31 nanophotonics, nanoelectronics, among others. 16 The most regular PANI nanowire arrays are produced by the template route using either hard templates, such as particle track-etched membranes 32,33 or anodized aluminum oxide membranes, 34,35 or soft templates, such as block copolymer assemblies or self-assembled surfactant phases, 36,37 geometry (e.g., vertical alignment) of conjugated polymer films as they are endowed by the template itself. The lower limit of wire diameters remains however restricted to typically tens of nanometers.…”