Investigation of polyaniline processibility using GPC/UV–vis analysis

In this work, we characterized the molecular weight and UV–vis spectra of polyaniline (PANI) simultaneously using a gel permeation chromatography (GPC) system equipped with a photodiode array (PDA) detector. Therefore, we constructed correlations between weight average molecular weight (Mw) values and UV–vis spectral features such as the ratio of quinoid units/benzenoid units (Q/B ratio), and the B peak positions for the continuum of discrete chromatographic fractions of PANI emeraldine base (EB). The correlation is further verified by electrochemical techniques. Using this correlation, we analyzed newly synthesized PANIs and investigated how the synthesis and post-treatment conditions impact the quality, uniformity, and processibility of the PANIs. The study also reveals that the portions with low molecular weights of PANI are more sensitive to the process conditions than those with high molecular weights.