Abstract: An electrolyte membrane (1) includes a base material layer (1) containing a hydrocarbon-based electrolyte as a main component, and a surface layer (5) laminated with the base material layer (1). The surface layer (5) is a layer containing, as a main component, a polymeric material having a hydroxyl group and a proton conductive group. The polymeric material that constitutes the surface layer (5) contains, for example, a first polymer having a hydroxyl group, and a second polymer having a proton conductive group. A matrix is formed by cross-linking the first polymer, and the second polymer can be held in the matrix.

Abstract: A method of manufacturing a proton-conductive polymer electrolyte membrane using polyvinyl alcohol (PVA) as a base material and having excellent proton conductivity and methanol blocking properties is provided. The method includes: heat-treating a precursor membrane including PVA and a water-soluble polymer electrolyte having a proton conductive group to proceed crystallization of the PVA; and chemically crosslinking the heat-treated precursor membrane with a crosslinking agent reactive with the PVA, to form a polymer electrolyte membrane in which a crosslinked PVA is a base material and protons are conducted through the electrolyte retained in the base material. The content of a water-soluble polymer except the PVA and the water-soluble polymer electrolyte in the precursor membrane is in a weight ratio of less than 0.1 with respect to the PVA.

Abstract: An electrolyte membrane (1) includes a base material layer (1) containing a hydrocarbon-based electrolyte as a main component, and a surface layer (5) laminated with the base material layer (1). The surface layer (5) is a layer containing, as a main component, a polymeric material having a hydroxyl group and a proton conductive group. The polymeric material that constitutes the surface layer (5) contains, for example, a first polymer having a hydroxyl group, and a second polymer having a proton conductive group. A matrix is formed by cross-linking the first polymer, and the second polymer can be held in the matrix.

Abstract: A method of manufacturing a proton-conductive polymer electrolyte membrane using polyvinyl alcohol (PVA) as a base material and having excellent proton conductivity and methanol blocking properties is provided. The method includes: heat-treating a precursor membrane including PVA and a water-soluble polymer electrolyte having a proton conductive group to proceed crystallization of the PVA; and chemically crosslinking the heat-treated precursor membrane with a crosslinking agent reactive with the PVA, to form a polymer electrolyte membrane in which a crosslinked PVA is a base material and protons are conducted through the electrolyte retained in the base material. The content of a water-soluble polymer except the PVA and the water-soluble polymer electrolyte in the precursor membrane is in a weight ratio of less than 0.1 with respect to the PVA.