Search results for "Note"
showing 10 items of 10709 documents
Photocleavable microcapsules built from photoreactive nanospheres.
2005
We show how photo-cross-linking of nanoparticles within the micrometer-sized thin oil shell of water-oil-water emulsion droplets leads to a new species of optically addressable microcontainers. The inner water droplet of these emulsions may contain drugs, dyes, or other water-soluble components, leading to filled containers. The thickness, mechanical stability, and light resistance of the container walls can be controlled in a simple way by the amount and adjustable photoreactivity of the nanoparticles. Importantly, the chemical bonds between the nanoparticles constituting the microcapsule shell can be cleaved photochemically by irradiation with UV light. This optically controlled destructi…
Alignment of Tellurium Nanorods via a Magnetization−Alignment− Demagnetization (“MAD”) Process Assisted by an External Magnetic Field
2009
Tellurium (Te) nanorods have been successfully aligned on a solid substrate via a magnetization-alignment-demagnetization ("MAD") process in the presence of an external magnetic field. Te nanorods carrying a poly(tert-butyl methacrylate) shell were first converted into magnetic nanocylinders by assembling magnetite nanoparticles on their surface via a hydrophobic interaction in THF. We demonstrate that, below a critical concentration of the nanoparticles, this assembly process is able to quantitatively tune the magnetite nanoparticles' density on the nanorods in terms of their stoichiometric ratio. Due to the polymer and surfactant on their surface, the formed magnetic nanocylinders are sol…
Enlarged pore size in nanoparticulated bimodal porous silicas: Improving accessibility
2016
Abstract Mass-transfer kinetics seems to be highly favored in siliceous materials constructed from the aggregation of mesoporous nanoparticles. Besides intra-particle mesopores, over the course of the aggregation process an inter-particle (textural) large pore system is generated. Diffusion constrains through the resulting hierarchically structured pore systems mainly depend on the characteristics of the intra-particle mesopores. By using alkanes as swelling agents, we have been able to significantly increase the intra-particle mesopore size in previously well characterized UVM-7 materials. The Winsor-III-like behavior associated with the presence of alkanes in the hydro-alcoholic reaction …
Coherent Electronic Coupling versus Localization in Individual Molecular Dimers
2004
International audience; The electronic excitation transfer and coherent electronic coupling strength were investigated in molecular dimers by spectrally resolved confocal fluorescence spectroscopy. The direct probe of electronic coupling strength distribution was possible due to static disorder in polymer host by single molecule measurements. The dimers with delocalized excitation were also found in comparison to emission originated from localized states. The delocalized and localized state transitions were observed for dimers which were attributed to structural fluctuations of guest-host system.
Impact of operation condition on temperature distribution in single cell of polymer electrolyte fuel cell operated at higher temperature than usual
2016
For improving performance of the stationary Polymer Electrolyte Fuel Cell (PEFC) system, the cell operating temperature up to 90°C will be preferred in Japan during the period from 2020 to 2030. To understand the operation of the PEFC system under relatively high temperature conditions, detail heat and mass transfer analysis is required. The main focus of this study is to analyze the PEFC performance under operational conditions, such as initial operational temperature of cell (Tini), relative humidity of supply gas, and the cathode gas type, temperature distribution in a cell of PEFC (using Nafion membrane) under relatively higher operating temperature conditions. The in-plane temperature …
Stereoselective synthesis and properties of 1,3-bis(dicyanomethylidene)indane-5-carboxylic acid acceptor fragment containing nonlinear optical chromo…
2016
A series of organic push–pull type chromophores using indane-1,3-dione 5-carboxylic acid (IDCA) and novel 1,3-bis(dicyanomethylidene)indane 5-carboxylic acid (CICA) electron acceptor fragments have been synthesized and characterized. NMR and X-ray analysis revealed that condensation reactions with the CICA fragment were stereoselective and yielded benzylidenes and azomethines with E double bond configurations. Due to the non-planar geometry these compounds are chiral and were acquired as a racemic mixture. The subsequent functionalization of the carboxylic acid group with 5,5,5-triphenylpentan-1-ol yielded solution-processable glass forming materials (6, 8, 10, 13) with glass transition tem…
Dynamics of weak interactions in the ligand layer of meta-mercaptobenzoic acid protected gold nanoclusters Au68(m-MBA)32 and Au144(m-MBA)40
2020
Atomically precise metal nanoclusters, stabilized and functionalized by organic ligands, are emerging nanomaterials with potential applications in plasmonics, nano-electronics, bio-imaging, nanocatalysis, and as therapeutic agents or drug carriers in nanomedicine. The ligand layer has an important role in modifying the physico-chemical properties of the clusters and in defining the interactions between the clusters and the environment. While this role is well recognized from a great deal of experimental studies, there is very little theoretical information on dynamical processes within the layer itself. Here, we have performed extensive molecular dynamics simulations, with forces calculated…
Interfacial Assembly and Jamming Behavior of Polymeric Janus Particles at Liquid Interfaces
2017
The self-assembly and interfacial jamming of spherical Janus nanoparticles (JNPs) at the water/oil interface were investigated. Polymeric JNPs, made by cross-linking polystyrene-block-polybutadiene-block-poly(methyl methacrylate) (PS-PB-PMMA), with a high interfacial activity assemble at the water/oil interface. During the self-assembly at the interface, the interfacial energy was reduced and a dynamic interlayer was observed that is responsive to the pH of the aqueous phase. Unlike hard particles, the JNPs are composed of polymer chains that can spread at the liquid-liquid interface to maximize coverage at relatively low areal densities. In a pendant drop geometry, the interfacial area of …
Structural and Gelation Characteristics of Metallo-Supramolecular Polymer Model-Network Hydrogels Probed by Static and Dynamic Light Scattering
2021
Supramolecular polymer gels are a promising class of materials whose polymer components are connected by transient bonds such as metal–ligand interactions, thereby spanning a dynamic network throug...
Reactive nanorods based on activated esterpolymers: a versatile template-assisted approach for the fabrication of functional nanorods
2011
A new route for the fabrication of polymeric nanorods with functional moieties via post-modification of reactive nanorods is described. To this end reactive nanorods with a homogenous and narrow size distribution were fabricated by utilizing an anodic aluminium oxide (AAO) template-assisted approach. The nanorods are based on activated pentafluorophenyl esters, to enable quantitative post-modification with amines under very mild reaction conditions yielding the corresponding functionalized amide. Post-modification with fluorescent dyes as well as the conversion into well-dispersed rod-shaped poly(N-isopropylacrylamide) (PNIPAM) hydrogels that exhibit a thermal-responsive phase transition wa…