Reports: AC10
46784-AC10 Synthesis and Characterization of Novel Hybrid Organic-Inorganic Proton Conducting Membranes
We prepared sintered self-assembled nanoporous silica colloidal crystals modified with poly(3-sulfopropyl-methacrylate) and poly(stryrenesulfonic acid) brushes covalently attached to the nanopore surface. The resulting robust membranes possess temperature and humidity-dependent proton conductivity of ~2 × 10-2 S cm-1 at 30 °C and 94% R.H., ~1 × 10-2 S cm-1 at 85 °C and 60% R.H., and water uptake of ca. 20 wt% at room temperature. We also prepared proton conductive membranes by self-assembly of silica nanospheres modified with poly(3-sulfopropylmethacrylate) and poly(stryrenesulfonic acid) brushes of different thickness.
We demonstrated that sintered self-assembled nanoporous silica colloidal crystals modified with poly(3-sulfopropyl-methacrylate) and poly(stryrenesulfonic acid) brushes covalently attached to the nanopore surface possess high proton conductivity and water uptake. Combined with the extensive set of other potential advantages including a continuous network of ordered nanopores with tunable sizes providing mechanical stability and water retention, the ability to optimize the surface-bound polyelectrolyte brush structure, and the mechanical stability of the inorganic matrix, we believe that we provided a proof-of-principle for a novel promising colloid-based proton conductive material. Work is under way to examine the long term stability and methanol permeability of the novel membranes, and to construct fuel cells using these membranes in order to study their electrochemical performance and to confirm their utility for fuel cell applications. We also prepared proton conductive membranes by self-assembly of silica nanospheres modified with poly(3-sulfo-propylmethacrylate) and poly(stryrenesulfonic acid) brushes of different thickness. These membranes showed a slightly higher conductivity and water uptake but poor mechanical properties.
