Self-assembled lamellar nanochannels in polyoxometalate-polymer nanocomposites for proton conduction

Nanocomposite electrolytes with lamellar proton-conducting channels were prepared through the electrostatic self-assembly of a polyoxometalate (H3PW12O40) and a comb copolymer poly(4-methlstyrene)-graft-poly(N-vinyl pyrrolidone). [Display omitted] The construction of nanostructured ion-transport channels is highly desirable in the design of advanced electrolyte materials, as it can enhance ion conductivity by offering short ion-transport pathways. In this work, we present a supramolecular strategy to fabricate a nanocomposite electrolyte containing highly ordered lamellar proton-conducting nanochannels, by the electrostatic self-assembly of a polyoxometalate H3PW12O40 (PW) and a comb copolymer poly(4-methlstyrene)-graft-poly(N-vinyl pyrrolidone). PW can effectively regulate the self-assembling order of polymer moieties to form a large-range lamellar structure, meanwhile, introducing protons into the nanoscale lamellar domains to build proton transport channels. Moreover, the rigid PW clusters contribute a remarkable mechanical reinforcement to the nanocomposites. The lamellar nanocomposite exhibits a conductivity of 4.3 × 10−4 S/cm and a storage modulus of 1.1 × 107 Pa at room temperature. This study provides a new strategy to construct nanostructured ion-conductive pathways in electrolyte materials.