Electric field processing to control the structure of titanium oxide/sulfonated poly (ether ether ketone) hybrid proton exchange membranes

With the aim to improve the conductivity of proton exchange membranes (PEMs), an external AC electric field is applied to a sulfonated poly (ether ether ketone) (SPEEK)-titanium (IV) oxide (TiO2) hybrid casting solution during solvent evaporation. Present technique gives a potentially useful method to fabricate PEMs with oriented proton channels, and resulting in increased conductivity by 75% in the trans-plane direction versus normal methods. In addition, reciprocation of TiO2 under the AC electric field prevents the nanoparticles from aggregating and improves mechanical strength of the PEMs. Factors affect the proton channels' alignment degree such as the applied field magnitude and frequency are also investigated. (C) 2013 Elsevier B.V. All rights reserved.