Layer by layer self-assembly fabrication of high temperature proton exchange membrane based on ionic liquids and polymers

The multicomponent membranes based on the polymer of sulfonated polyetheretherketone (SPEEK) as polyanion, the polymer of polyurethane (PU) and ionic liquid (IL) cation of 1-butyl-3-methylimidazolium (bmim(+)) as polycations were fabricated with layer by layer (LBL) self-assembly technique. After 100 layers deposition, the (SPEEK/PU/SPEEK/bmim)(100) membranes were obtained and they showed the potential as membrane electrolytes working in proton exchange membrane fuel cell (PEMFC). Phosphoric acid (PA) molecules were doped in (SPEEK/PU/SPEEK/bmim)(100) membranes and uctivity of (SPEEK/PU/SPEEK/bmim)(100)/60%PA membranes could reach 1.03 x 10(-1) S/cm at 160 degrees C, which was higher than the value of 6.27 x 10(-2) S/cm for the comparative (SPEEK/PU)(210)/60%PA membranes under anhydrous conditions. Moreover, (SPEEK/PU/SPEEK/bmim)(100)/PA membranes exhibited the satisfactory mechanical property. The tensile stress was 2.38 MPa for (SPEEK/PU/SPEEK/bmim)100/PA membranes at room temperature. This research indicated that the properties of multicomponent LBL self-assembly membrane electrolyte could be optimized through adjusting the components. (C) 2018 Elsevier B.V. All rights reserved.