The review is devoted to key problems in the development of modern proton‐conducting membranes for hydrogen power assuming its progress for using in fuel cells working at enhanced temperatures without catalysts poisoning and providing stable high proton conductivity and improved mechanical properties. Modern trends in the synthesis approaches such as application of emulsion polymerization and novel efforts for the modification of polymer membranes by chemically stable nanoparticles, carrying protons, are discussed as compared to commercially used membrane materials such as Nafion and Aquivion. The crucial role of advanced structural methods to recognize subtle features of molecular ordering and formation of conducting channels in membranes is considered, focusing on neutron scattering as the most powerful instrument for the analysis of ionomers and other nanoscale structures by means of selective isotopic contrasting structural elements in membrane materials. The integration of novel methods of emulsion polymerization and use of nanodiamonds and other nanoparticles embedded into polymer matrices is prospective in the creation of new generations of membrane materials with higher functional properties.

Compositional proton-conducting membranes based on perfluorinated Aquivion®-type copolymers modified by detonation nanodiamonds (DND) with positively charged surfaces were prepared to improve the performance of hydrogen fuel cells. Small-angle neutron scattering (SANS) experiments demonstrated the fine structure in such membranes filled with DND (0–5 wt.%), where the conducting channels typical for Aquivion® membranes are mostly preserved while DND particles (4–5 nm in size) decorated the polymer domains on a submicron scale, according to scanning electron microscopy (SEM) data. With the increase in DND content (0, 0.5, and 2.6 wt.%) the thermogravimetric analysis, potentiometry, potentiodynamic, and potentiotatic curves showed a stabilizing effect of the DNDs on the operational characteristics of the membranes. Membrane–electrode assemblies (MEA), working in the O2/H2 system with the membranes of different compositions, demonstrated improved functional properties of the modified membranes, such as larger operational stability, lower proton resistance, and higher current densities at elevated temperatures in the extended temperature range (22–120 °C) compared to pure membranes without additives.

No abstract

Stretching of membranes with low molecular weight makes structure rearrangement according to neutron scattering data on D2O-filled membranes.