Enhanced conductivity in sorbitol-treated PEDOT–PSS. Observation of an in situ cyclodehydration reaction

Films of sorbitol-treated PEDOT–PSS or sorbitol-treated PEDOT (oxidized form) undergo a cyclodehydration reaction in the presence of the polymer to form 1,6-anhydrosorbitol. We offer evidence that both sorbitol and 1,6-anhydrosorbitol remain in the film and contribute to the enhanced conductivity. This reaction offers a new explanation for the observed “loss” of sorbitol upon annealing, and should be considered in any explanation of the role of sorbitol as an additive for PEDOT–PSS.