Origin of Bulk Nanoscale Morphology in Conducting Polymers

The direct one-step chemical transformation of a liquid monomer to bulk conducting polymer nanofibers has opened new opportunities in the field of energy storage and chemical/ biological sensors.1 The conducting polymer polyaniline has evolved as a prototype system in the study of this transformation, and there are now several empirical methods to convert aniline directly to bulk conducting polyaniline nanofibers.2-13 The key to broadening this phenomenon to other conducting and classical polymers would be in uncovering the mechanism of nanofiber formation. Here we report that surfaces such as the walls of the reaction vessel and/or intentionally added surfaces play a dramatic role in the evolution of nanofibrillar morphology.14 Nucleation sites on surfaces promote the accumulation of aniline dimer that reacts further to yield aniline tetramer, which (surprisingly) is entirely in form of nanofibers and whose