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411.
Sara Shariki Soon Yee Liew Wim Thielemans Darren A. Walsh Charles Y. Cummings Liza Rassaei Matthew J. Wasbrough Karen J. Edler Michael J. Bonn�� Frank Marken 《Journal of Solid State Electrochemistry》2011,15(11-12):2675-2681
Polyaniline of low molecular weight (ca. 10?kDa) is combined with cellulose nanofibrils (sisal, 4?C5?nm average cross-sectional edge length, with surface sulphate ester groups) in an electrostatic layer-by-layer deposition process to form thin nano-composite films on tin-doped indium oxide (ITO) substrates. AFM analysis suggests a growth in thickness of ca. 4?nm per layer. Stable and strongly adhering films are formed with thickness-dependent coloration. Electrochemical measurements in aqueous H2SO4 confirm the presence of two prominent redox waves consistent with polaron and bipolaron formation processes in the polyaniline?Cnanocellulose composite. Measurements with a polyaniline?Cnanocellulose film applied across an ITO junction (a 700?nm gap produced by ion beam milling) suggest a jump in electrical conductivity at ca. 0.2?V vs. SCE and a propagation rate (or percolation speed) two orders of magnitude slower compared to that observed in pure polyaniline This effect allows tuning of the propagation rate based on the nanostructure architecture. Film thickness-dependent electrocatalysis is observed for the oxidation of hydroquinone. 相似文献
412.
We present confocal microscopy experiments on the wetting of phase-separated colloid-polymer mixtures. We observe that an unusually thick wetting layer of the colloid-rich phase forms at the walls of the glass container that holds the mixture. Because of the ultralow interfacial tension between the colloid-rich and the polymer-rich phases, the thermally activated roughness of the interfaces becomes very big and measurable. We observe that close to the critical point the roughness of the interface between the wetting layer and the polymer-rich phase decreases with decreasing layer thickness: large excursions of the interface are confined in the wetting layer. The measured relationship between the roughness and the thickness of the wetting layer is in qualitative agreement with the predictions of renormalization group theory for short-range forces and complete wetting. 相似文献
413.
Olivier de Bonn Anton Hammerl Thomas M. Klaptke Peter Mayer Holger Piotrowski Helmut Zewen 《无机化学与普通化学杂志》2001,627(8):2011-2015
The predominant species in the plume residues resulting from the incomplete combustion of methylhydrazine (MMH)/N,N‐dimethylhydrazine (UDMH) and N2O4 (NTO) in rocket engines are methylhydrazinium and N,N‐dimethylhydrazinium nitrate. Both compounds were synthesized, characterized and their crystal structures were determined. The thermal, shock and friction sensitivity of these compounds was investigated. For both compounds the products formed in their thermal decompositions were determined. 相似文献
414.
Dr. Chaolei Hu Pit van Bonn Prof. Dr. Dan E. Demco Prof. Dr. Carsten Bolm Prof. Dr. Andrij Pich 《Angewandte Chemie (International ed. in English)》2023,62(34):e202305783
Mechanochemical approaches are widely used for the efficient, solvent-free synthesis of organic molecules, however their applicability to the synthesis of functional polymers has remained underexplored. Herein, we demonstrate for the first time that mechanochemically triggered free-radical polymerization allows solvent- and initiator-free syntheses of structurally and morphologically well-defined complex functional macromolecular architectures, namely stimuliresponsive microgels. The developed mechanochemical polymerization approach is applicable to a variety of monomers and allows synthesizing microgels with tunable chemical structure, variable size, controlled number of crosslinks and reactive functional end-groups. 相似文献
415.
Dr. Giulia Giubertoni Gijs Rombouts Dr. Federico Caporaletti Dr. Antoine Deblais Rianne van Diest Prof. Dr. Joost N. H. Reek Prof. Dr. Daniel Bonn Prof. Dr. Sander Woutersen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202213424
Inspired by ideas from NMR, we have developed Infrared Diffusion-Ordered Spectroscopy (IR-DOSY), which simultaneously characterizes molecular structure and size. We rely on the fact that the diffusion coefficient of a molecule is determined by its size through the Stokes–Einstein relation, and achieve sensitivity to the diffusion coefficient by creating a concentration gradient and tracking its equilibration in an IR-frequency resolved manner. Analogous to NMR-DOSY, a two-dimensional IR-DOSY spectrum has IR frequency along one axis and diffusion coefficient (or equivalently, size) along the other, so the chemical structure and the size of a compound are characterized simultaneously. In an IR-DOSY spectrum of a mixture, molecules with different sizes are nicely separated into distinct sets of IR peaks. Extending this idea to higher dimensions, we also perform 3D-IR-DOSY, in which we combine the conformation sensitivity of femtosecond multi-dimensional IR spectroscopy with size sensitivity. 相似文献
416.
The European Physical Journal E - This work aims at finding optimal navigation policies for thin, deformable microswimmers that progress in a viscous fluid by propagating a sinusoidal undulation... 相似文献