ABSTRACT
Although known for over 150 years, research on polyaniline (PANI) really took off in the 1980s after the discovery of conducting polymers as (Figure 586). Research has mainly focused on understanding the chemical structure and electronic conduction mechanisms, designing polymerization techniques, and developing chemical or physical modication methods that enables PANI processable. With the emergence of nanoscience and nanotechnology, synthesizing PANI nano-bers, has garnered attention in recent years (Figure 586). This is due to their novel properties and wide potential application in nanoscale engineering. Recently, many research groups have reported that the inherent anisotropic geometry of conducting polymer nanostructures provides signicant advantages over their bulky counterparts. Accordingly, the nanostructured PANI has offered unique opportunities for creating innovative applications in the areas of hydrogen storage,1,2 sensors,3-5 solar cells,6,7 electrochemical capacitors,8,9 electronic devices,10,11 batteries,12 and catalysis,13-15 which are attributed to the benecial characteristics at the nanometer scale. The most important feature is that the properties
of these conducting polymers become dependent on their size and shape when their dimensions are decreased to the nanoscale. To understand the size/shape-property relationship, it is necessary to develop reliable synthetic methods that can preciously tailor the nanostructured PANI.16,17 Extensive research in the synthesis and characterization of nanostructured PANI has the main aim to design nanomaterials having unique physicochemical properties and wide range applicability. However, in contrast to inorganic nanomaterials, it is intrinsically difcult to control the morphology of organic polymer nanomaterials whose dimensional stability drops dramatically at the nanoscale because of the low viscosity of conducting polymers dissolved in organic solvent.18 The objective of this review is to provide insight into the recent developments on synthesis, characterization and processing, and application of pure PANI nanostructures.
