Anion exchange membranes (AEM) are solid polymer electrolytes that facilitate ion transport in fuel cells. In this study, a polystyrene-b-poly(vinylbenzyl trimethylammonium) diblock copolymer was evaluated as potential AEM and compared with the equivalent homopolymer blend. The diblock had a 92% conversion of reactive sites with an IEC of 1.72 6 0.05 mmol g 21 , while the blend had a 43% conversion for an IEC of 0.80 6 0.03 mmol g 21 . At 50 C and 95% relative humidity, the chloride conductivity of the diblock was higher, 24-33 mS cm 21 , compared with the blend, 1-6 mS cm 21 . The diblock displayed phase separation on the length scale of 100 nm, while the blend displayed microphase separation ($10 lm). Mechanical characterization of films from 40 to 90 microns thick found that elasticity and elongation decreased with the addition of cations to the films. At humidified conditions, water acted as a plasticizer to increase film elasticity and elongation. While the polystyrene-based diblock displayed sufficient ionic conductivity, the films' mechanical properties require improvement, i.e., greater elasticity and strength, before use in fuel cells.

PurposeWe investigated the autofluorescence (AF) signature of the microscopic features of retina with age-related macular degeneration (AMD) using 488 nm excitation.MethodsThe globes of four donors with AMD and four age-matched controls were embedded in paraffin and sectioned through the macula. Sections were excited using a 488 nm argon laser, and the AF emission was captured using a laser scanning confocal microscope (496–610 nm, 6 nm resolution). The data cubes were then analyzed to compare peak emission spectra between the AMD and the controls. Microscopic features, including individual lipofuscin and melanolipofuscin granules, Bruch’s Membrane, as well macroscopic features, were considered.ResultsOverall, the AMD eyes showed a trend of blue-shifted emission peaks compared with the controls. These differences were statistically significant when considering the emission of the combined RPE/Bruch’s Membrane across all the tissue cross-sections (p = 0.02).ConclusionsThe AF signatures of ex vivo AMD RPE/BrM show blue-shifted emission spectra (488 nm excitation) compared with the control tissue. The magnitude of these differences is small (~4 nm) and highlights the potential challenges of detecting these subtle spectral differences in vivo.