Polymer nanofilms with enhanced microporosity by interfacial polymerization

Highly permeable and selective membranes are desirable for energy-efficient gas and liquid separations. Microporous organic polymers have attracted significant attention in this respect owing to their high porosity, permeability, and molecular selectivity. However, it remains challenging to fabricate selective polymer membranes with controlled microporosity which are stable in solvents. Here we report a new approach to designing crosslinked, rigid polymer nanofilms with enhanced microporosity by manipulating the molecular structure. Ultra-thin polyarylate nanofilms with thickness down to 20 nm were formed in-situ by interfacial polymerisation. Enhanced microporosity and higher interconnectivity of intermolecular network voids, as rationalised by molecular simulations, are achieved by utilising contorted monomers for the interfacial polymerisation. Composite membranes comprising polyarylate nanofilms with enhanced microporosity fabricated in-situ on crosslinked polyimide ultrafiltration membranes show outstanding separation performance in organic solvents, with up to two orders of magnitude higher solvent permeance than membranes fabricated with nanofilms made from noncontorted planar monomers

Proton conducting composite membranes from polyether ether ketone and heteropolyacids for fuel cell applications

A series of composite membranes based on sulfonated polyether ether ketone with embedded powdered heteropolycompounds was prepared and their electrochemical and thermal properties were studied. An increase in degree of sulfonation as well as introduction of these fillers resulted in increased Tg and enhanced membrane hydrophilicity, bringing about a substantial gain in proton conductivity. The conductivity of the composite membranes exceeded 10 122 S/cm at room temperature and reached values of about 10 121 S/cm above 100C.Peer reviewed: YesNRC publication: Ye

[P1.037] Sorption of CO2/CH4 mixtures in PIM-1 and PTMSP membranes

Sorption of pure methane, carbon dioxide and their binary mixtures in two glassy polymers, poly(1-trimethylsilyl-1-propyne) (PTMSP), and the first polymer of intrinsic microporosity (PIM-1), has been studied experimentally and theoretically, at 35.0 \ubaC. Measurements were obtained on a newly designed pressure decay sorption apparatus which allowed to measure sorption isotherms at constant partial pressure of one component of the gas mixture. Results indicate the presence of a competition for available polymer matrix sites, which is not surprising due to the nature of physical sorption in glassy matrices

Designing the next generation of proton-exchange membrane fuel cells.

With the rapid growth and development of proton-exchange membrane fuel cell (PEMFC) technology, there has been increasing demand for clean and sustainable global energy applications. Of the many device-level and infrastructure challenges that need to be overcome before wide commercialization can be realized, one of the most critical ones is increasing the PEMFC power density, and ambitious goals have been proposed globally. For example, the short- and long-term power density goals of Japan's New Energy and Industrial Technology Development Organization are 6 kilowatts per litre by 2030 and 9 kilowatts per litre by 2040, respectively. To this end, here we propose technical development directions for next-generation high-power-density PEMFCs. We present the latest ideas for improvements in the membrane electrode assembly and its components with regard to water and thermal management and materials. These concepts are expected to be implemented in next-generation PEMFCs to achieve high power density

A solution-processable and ultra-permeable conjugated microporous thermoset for selective hydrogen separation

10.1038/s41467-020-15503-6Nature Communications111163