Rymsha K. Synthesis and properties of organic-inorganic proton conductive materials

The dissertation is devoted to the development of new polymer and organic-inorganic materials with proton conductive properties for the use in fuel cells. The synthesis strategy was proposed in which a polymer matrix of the composite was formed by UV-initiated copolymerization of acrylic monomers, and a silica network of the hybrid materials was formed in situ due to simultaneous sol-gel process of the precursor – tetraethoxysilane. The polyacrylic and polymeric-silica materials of varied compositions based on poly(acrylamide-co-acrylonitrile-co-3-sulfopropylacrylate potassium salt) and poly(acrylic acid-co-acrylonitrile-co-3-sulfopropylacrylate potassium salt-co-ethylene glycol dimethylacrylate) have been synthesized. The effect of the polymer matrix composition, inorganic component content, sulfoсomponent nature on the internal morphology and properties: thermal stability, water uptake, swelling in methanol, free surface energy, proton conductivity of the obtained materials was established. The proton conductivity of the membranes based on poly(acrylic acid-co-acrylonitrile-co-3-sulfopropylacrylate potassium salt-co-ethylene glycol dimethylacrylate) with added sol-gel system (1 - 7 mass %) reaches the values up to 1,12•10-2 Sm/cm. The proton transfer activation energy was calculated from the temperature dependence of proton conductivity using the Arrhenius equation (0.12 – 0.14 eV). According to the Rice and Roth model, the transport parameters of the membranes; proton diffusion coefficients were calculated using the Nernst-Einstein equation.