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We detect short-range surface plasmon-polariton (SR-SPP) resonances setup in individual silver nanoantenna structures at high-spatial resolution with a scanning, subnanometer electron probe. Both even and odd multipolar resonant modes are resolved up to sixth order, and we measure their spatial distribution in relation to nanoantenna structures at energies down to 0.55 eV. Fabry-Perot type SR-SPP reflection phase shifts are calculated from direct measurements of antinode spacings in high-resolution plasmonic field maps. We observe resonant SR-SPP antinode bunching at nanoantenna terminals in high-order resonant modes, and antinode shifts in nonhomogeneous local environments. Finally, we achieve good agreement of our experimental SR-SPP maps with numerical calculations of photon excited near fields, using a novel integrated photon excitation geometry.

Atomically thick graphene layers produced from graphite reveal unique electro-thermal, and mechanical properties, [1][2][3][4][5][6][7] and are considered to have a wide range of applications in nanoelectronics, catalysis and biosensing. [1,3,[8][9][10] Graphene monolayers exhibiting exceptional electron/hole carrier mobility have been prepared by mechanical exfoliation of highly ordered pyrolytic graphite, [1,3] by epitaxial growth using chemical vapour deposition of hydrocarbons onto silicon carbide, [11] or via thermal fusion of polycyclic aromatic hydrocarbons.[12] These methods are constrained by low yields and processing limitations, and more practical approaches based on the chemical [6,12,13] or thermal [15,16] reduction of exfoliated sheets of oxidised graphite (graphene oxide, GO) have been developed. High yields of GO monolayers, 0.78 nm in thickness, can be readily prepared by treatment of graphite under strongly acidic and oxidising conditions. [17][18][19] The GO single sheets can be readily dispersed in water and mounted onto substrates using spin-, dip-and spray-coating techniques, and reduced in situ to produce isolated graphene monolayers or transparent 2D films [20][21][22][23][24] with conductivities ranging from as low as 2 S cm À1 , [20] or 23 S cm À1, [15] to a value of 550 S cm À1 for a 10 nm-thick film, [20] comparable with polycrystalline graphite (1250 S cm À1).[25] Alternatively, aqueous dispersions of GO oxide can be chemically reduced directly to produce aggregated sols of graphene sheets that can be assembled into graphene thin films with a typical conductivity of 72 S cm À1. [26] Moreover, by undertaking the reduction step in the presence of poly(sodium 4-styrenesulfonate), [13] or pyrene butyrate, [14] or exploiting electrostatic repulsions between adjacent sheets in an alkaline medium, [26] stable aqueous dispersions of coated graphene monolayers have been produced. Similar approaches have been used to prepare stable graphene dispersions in polar organic solvents by chemical reduction of GO sheets functionalized with hydrophobic residues such as alkylamines, [27] phenyl isocyanate [6] or anhydrous hydrazine. [28] Alternatively, Coleman and coworkers [29] have recently prepared graphene dispersions by ultrasonicating graphite powders in various solvents, for example, N-methylpyrrolidinone, followed by subsequent fractionation using low-speed centrifugation to produce sols comprising single and multilayered graphene sheets. Interestingly, thin films produced from the above dispersions showed conductivity values of $65 S cm À1, comparable to that of chemically reduced graphene oxide paper.Recent studies have demonstrated that hydrophobic carbon nanotubes (CNTs) can be successfully functionalized using single-stranded (ss) DNA to produce novel nanocomposites with potential applications in nanoelectronics and bionanotechnology. [30,31] Adsorption of the biomolecules onto the surface of the CNTs is facilitated by non-covalent p-p stacking interactions involving both purine and pyrimidi...

The resemblance between colloidal and molecular polymerization reactions has been recognized as a powerful tool for the fundamental studies of polymerization reactions, as well as a platform for the development of new nanoscale systems with desired properties. Future applications of colloidal polymers will require nanoparticle (NP) ensembles with a high degree of complexity that can be realized by hetero-assembly of NPs with different dimensions, shapes and compositions. In the present work, we have developed a method to apply strategies from molecular copolymerization to the co-assembly of gold nanorods with different dimensions into random and block copolymer structures (plasmonic copolymers). The approach was extended to the co-assembly of random copolymers of gold and palladium nanorods. A kinetic model validated and further expanded the kinetic theories developed for molecular copolymerization reactions.

In this paper we focus on the synthesis and use of superacids, in particular 1,1,2,2tetrafluoroethanesulfonic acid (TFESA), and describe how these can be optimized for reactions of key industrial importance. One area of considerable interest is the field of superacid catalysis and, specifically, the development of safer and more cost-effective acid catalysts. We report a new simplified route for preparation of these acids, making these more readily available and opening up a large number of opportunities. Partially fluorinated superacids offer several advantages over the acids commonly used in catalysis (sulfuric, hydrofluoric acid and aluminium chloride): lower loadings, lower reaction temperatures (leading to increased selectivity), fewer by-products, shorter reaction times and higher throughput. TFESA and its longer chain analogs are much less volatile than triflic acid (CF 3 SO 3 H). We tested these superacids in several processes (aromatic alkylation, acylation of arenes, isomerization, oligomerization and the Fries rearrangement). These materials are excellent acid catalysts, comparable to triflic acid, and yet easier to handle. We have also prepared supported versions of these catalysts and introduced the ability to recycle.