Search results for "composites"
showing 10 items of 1905 documents
Two-dimensional self-assembly of disulfide functionalized bis-acylurea: a nanosheet template for gold nanoparticle arrays.
2010
A new functional bis-acylurea molecule allows a two-stage self-organization process. It self-organizes--at first--into 2D nanosheets with disulfide groups at the surface, which act--in the second stage--as a template for gold nanoparticle arrays.
Self-assembly of amphiphilic imidazolium-based hexa-peri-hexabenzo-coronenes into fibreous aggregates
2007
Imidazolium-based amphiphilic hexa-peri-hexabenzocoronenes were synthesized and shown to undergo ordered columnar self-assembly in solid-state as well as in solution to yield defined nanofibers upon solution drop casting onto solid substrate.
Low temperature catalytic combustion of propane over Pt-based catalyst with inverse opal microstructure in microchannel reactor
2007
A novel Pt-based catalyst with highly regular, periodic inverse opal microstructure was fabricated in a microchannel reactor, and catalytic testing revealed excellent conversion and stable activity for propane combustion at low temperatures.
Spin-crossover complex encapsulation within a magnetic metal-organic framework.
2016
The solid-state incorporation of a mononuclear iron(III) complex within the pores of a magnetic 3D metal–organic framework (MOF) in a single crystal to single crystal process leads to the formation of a new hybrid material showing both a guest-dependent long-range magnetic ordering and a spin-crossover (SCO) behaviour.
2D magnetic MOFs with micron-lateral size by liquid exfoliation
2020
The isolation in large amounts of high-quality flakes of 2D MOFs remains a challenge. In this work, we develop a liquid exfoliation procedure to obtain nanosheets for a whole family of Fe-based magnetic MOFs, MUV-1-X. High-quality crystalline layers with lateral sizes of 8 µm and thicknesses of 4 nm, which keep the structural integrity and magnetic properties, are obtained.
Folded Cr12Co12 and Cr12Ni12 wheels: a sharp increase in nuclearity of heterometallic chromium rings
2014
Two novel record-sized heterometallic Cr12M12 (M = Co, Ni) chromium wheels with an unusual saddle-like architecture are created by reacting appropriate precursor complexes with the bridging ligand 2,2'-bipyrimidine.
Improvement of flame spraying PEEK coating characteristics using lasers
2011
Flame spraying is frequently used for PEEK coatings elaboration on metallic surfaces. However, this process has a certain number of limitations particularly considering the quality of the coatings like high porosity or low interfacial adherence. For that reason a thermal post-processing is often necessary. From all of the processes which can be used (flame, oven, etc.), laser can be an interesting technology. Then, the aim of this study is to analyse the dependence of the morphological structure (compactness) and the adherence of the flame sprayed PEEK coatings to the stainless steel (304L) and aluminium alloy (AA2017) substrates on laser parameters. Moreover, the influence of the laser bea…
Prehnite: Structural similarity of the monoclinic and orthorhombic polymorphs and their Si/Al ordering
1990
Abstract Two modifications of the naturally occurring mineral prehnite, Ca 2 Al(Si 3 AlO 10 )(OH) 2 , are characterized by precise single crystal diffraction methods. The two forms are topologically identical. They differ only in the siting of one Al and one Si atom per unit cell: these switch their places in two of the tetrahedrally coordinated sites. This appears to be the only known case where a silicate occurs with two differently ordered tetrahedral distributions of Al and Si atoms. The two forms are not polytypes according to the current definition of polytypes. The two modifications are so similar to each other that they differ only in the eighth coordination sphere.
Control of grain size and morphologies of nanograined ferrites by adaptation of the synthesis route: mechanosynthesis and soft chemistry
2003
Abstract Nanocrystalline Fe-based spinels with composition Fe 2.5 Ti 0.5 O 4 can be synthesized using two different routes: soft chemistry and high-energy ball milling. This paper is focussed on the fact that each type of synthesis process can lead to powders with a crystallite size of about 15 nm but with significant differences in the grain size distribution and the agglomeration state. Whereas in the case of mechanosynthesis, the ball-milled powders consist of aggregates, those obtained by soft chemistry are very well dispersed. Moreover the chosen investigated nanopowders present a blocked/superparamagnetic transition depending on the grain size. The grain size morphologies obtained by …
Dispersions of Nanoclays of Different Shapes into Aqueous and Solid Biopolymeric Matrices. Extended Physicochemical Study
2010
Dispersions of nanofillers into aqueous and solid biopolymeric matrices were studied from the physicochemical viewpoint. This work was carried out based on the idea that the combination of biopolymers, derived from renewable resources, and nanofiller, environmentally friendly, may form a new generation of nanomaterials with excellent and unique properties at low cost. To this purpose, two pectins with different degrees of methyl esterification and nanoclays like halloysite and laponite RD were selected. The thermodynamic and structural studies on the aqueous mixtures of pectin and nanoclay were able to discriminate the interactions, which control the adsorption of pectin onto the filler and…