“…Furthermore, no conductivity enhancement was observed when a compound of high dielectric constant, such as nitromethane (e = 39), methanol (e = 38), or acetonitrile (e = 38) was added to an aqueous solution of PEDOT:PSS. Our experiments also indicate that the additive does not act simply as a plasticizer, as proposed by Inganäs and co-workers [6,7] If the additive simply acted as a plasticizer, other liquid additives, like heptanol, which is liquid at room temperature and has a boiling point close to that of EG, should also enhance the conductivity. However, no conductivity enhancement was observed.…”