We report on the fabrication and optical characterization of dense and ordered arrays of metal nanoparticles. The metal arrays are produced by reducing metal salts in block copolymer (BCP) templates made by solvent annealing of poly(styrene-b-4-vinylpyridine) (PS-b-P4VP) or poly(styrene-b-ethylene oxide) (PS-b-PEO) diblock copolymer thin films in mixed solvents. The gold and gold/silver composite nanoparticle arrays show characteristic surface plasmon resonances in the visible wavelength range. The patterning can be applied over large areas onto various substrates. We demonstrate that these metal nanoparticle arrays on metal thin films interact with surface plasmon polaritons (SPPs) that propagate at the film/nanoparticle interface and, therefore, modify the dispersion relation of the SPPs.
We demonstrate a method to fabricate high-quality patterned micelle arrays using poly(styrene-b-4-vinylpyridine) (PS-b-P4VP) block copolymer. Long-range order of the PS-b-P4VP micelle in hexagonal arrays was induced by topographic grating patterns during solvent annealing. The size and row spacing of block copolymer micelle arrays created in this way were uniform. By controlling the thickness of the polymer on the crests and in the troughs of the grating patterns, we prepared PS-b-P4VP micelle arrays having different sizes.
Proton-conducting, thermally and electrochemically stable, heterocycle-grafted polysiloxanes have
been synthesized via hydrosilylation of vinyl or allyl functionalized weakly basic heterocyclic motifs with a
polymethylhydrosiloxane precursor. The basicity of the amphoteric heterocycles was tuned by introducing electron-withdrawing groups, whose presence also produced a decrease in the polymers' glass transition temperature. The
proton conductivity depended strongly on the T
g of the polymer matrix and the volume fraction of proton carriers,
while the effect of reducing the pK
a of the heterocycle was less pronounced. The resulting polymers showed the
highest reported proton conductivities of up to 0.1 mS/cm at temperatures below 80 °C and up to 5 mS/cm at 180
°C when doped with trifluoroacetic acid.
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