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Polysulfone (PSU) –based Proton Exchange Membranes (PEMs) were synthesized from different pre-sulfonated monomers and evaluated for use in a vanadium redox flow battery (VRFB). Two types of sulfonated monomers, containing either an allyl sulfonate or styrene sulfonate group, were synthesized by a Mizoroki-Heck reaction from a 4,4′-difluorodiphenyl sulfone derivative. These monomers were polymerized with 4,4′-(hexafluoroisopropylidene)diphenol to give partially fluorinated PSUs with controlled placement and content of sulfuric acid moieties. PEMs were then fabricated by solution casting and characterized against the membranes made from traditional backbone sulfonated PSU. The new PEMs revealed desirable physical properties and performance in a VRFB cell competitive with the Nafion membrane. Furthermore, each PEM with a different acid side-chain structure exhibited varying properties and performance depending on its acid content, providing a path to optimization.

We previously reported that a branched quaterthiophene donor chromophore functionalized with a phthalhydrazide hydrogen bonding (H-bonding) unit (MeBQPH) gives twofold more efficient bulk heterojunction organic solar cells (with C60 acceptors) compared to a nearly identical donor incapable of H-bonding (MeBQPME). Here, scanning tunneling microscopy (STM) studies confirm the formation of MeBQPH trimer rosettes on Au(1 1 1) through phthalhydrazide H-bonding interactions that are sufficiently strong to compete with adsorbate/substrate interactions. The MeBQPME comparator molecule void of hydrogen bonding functionality does not similarly assemble on the metal surface. Complementary density functional theory (DFT) calculations facilitate a structural understanding of the MeBQPH donor assemblies and their strong stabilization through formation of six hydrogen bonds. STM studies also reveal the templated growth of C60 on ordered MeBQPH monolayers with C60 molecules preferentially occupying the threefold interstitial sites of the MeBQPH monolayer. This work supports the idea that H-bonding interactions can be used to control the morphology of organic donor–acceptor blends to potentially create efficient and stable bulk heterojunction photovoltaic devices.

Specifically angled, conjugated spiroindolinonaphthooxazine dimers (SNOD) have been synthesized. The photochromic reactions of two types of SNOD were studied under continuous UV irradiation in solvents of different polarity. Comparison of these results with the single unit provides the examination of the specific effect of substituents on their photochromic properties and relaxation kinetics. The photomerocyanine isomers showed positive solvatochromism, supporting the premise for a less polar quinoidal structure. The thermal closing rate at 25 °C ranged from 0.2 to 1.6 s−1 depending on the compound and solvent. Photochromism of these new compounds showed little dependency on solvent polarity and stable cyclability.