Lacking any excess polyelectrolyte to act as a buffer (such as in the case of PEDOT:PSS), the ion composition of pg2T-TT was found to be dependent on electrolyte concentration and pH (Figure ). At neutral pH, anion concentration in the polymer was positively correlated with electrolyte concentration at all states (exposed/doped/dedoped). The observed dependence of anion concentration in the polymer upon electrolyte concentration was larger than would be expected from a shift in doping state due to a Nernst-like shift in electrochemical potential (59 mV shift per decade of electrolyte concentration). Instead, a ~55% drop in dopant anion concentration was observed when decreasing electrolyte concentration from 100 to 10 mM, and a further ~40% drop from 10 to 1 mM (Figure ). The persistent (trapped) anion concentration within the rigorously dedoped film was also dependent on electrolyte concentration. The trapped anions were in an apparent equilibrium with the contacting aqueous electrolyte, undergoing a 30-40% decrease with each ten-fold decrease in electrolyte concentration (Figure ).