A Journey into the Determination of Polyaniline Molecular Weight

Over the last decades, the construction and design of conducting polymer-based materials have received a huge attention due to their special physico-chemical characteristics making them very useful and alternative materials in various fields. Among intrinsically conducting polymers, polyaniline (PANI) has been widely used and a pool of scientific research has been done to improve its properties and/or to combine it with other materials to get multifunction materials with enhanced efficiency. However, the scarce information is available to date on its molecular weight (Mw) limits obtaining structural information. In fact, owing to the poor solubility of the material the most part of the results concerns dimeric and oligomeric species, whereas a complete characterization of the longest chains is still far away. Since the synthetic strategies used to produce PANI critically affect its properties and chemical-physical characteristics, included Mw, the present work summarizes the most common methods applied for PANI synthesis and the different analytical approaches used to determine the Mw of the polymer and of its oligomers, in order to stimulate further investigation that can contribute to widen the information on this unique polymer.