Pivotal role of oligoanilines as regulator of polyaniline chain growth, helicity and overall morphology

Polyaniline (PANI) has received significant attention as conductive polymer owing to its simple and cost effective method of synthesis, light weight, environmentally benign nature etc. Furthermore, it offers many attractive features such as high conductivity, availability in different oxidation states, doping-dedoping using simple acid/base chemistry etc. Nanostructured PANI has been found to be even more impactful as single material or as component in composites. The mechanism behind oxidative polymerization of aniline is well researched and it has been found that supramolecular organization of the oligoanilines produced during aniline polymerization, dictates the fate of the final PANI chains. Thus, by judicious control over the structure as well as number of the oligomers, via manipulation of the polymerization parameters or by externally added oligomers, a significant degree of control over the PANI chain lengths, helicity or their morphology may be exercised. Besides generating potential polymeric chains of various utility, the oligomers themselves have been reported to be pretty effective in various similar applications. There are numerous reports and many reviews which explore the synthesis and applications of PANI chains and the role of oligoanilines. The present report revisits the recent progress in the field and further highlight the key role of the oligoanilines in design, synthesis and applications of PANI either as bulk material or composite component.