7,443 research outputs found
Removal of Confined Ionic Liquid from a Metal Organic Framework by Extraction with Molecular Solvents
This work was supported in part by NSF Grant No. CHE-1223988 and by EPSRC Grant No. EP/K00090X/1.Peer reviewedPostprin
PREPARATION, IDENTIFICATION AND BIOLOGICAL PROPERTIES OF NEW FLUORIDE NANOCOMPOUNDS
IndexaciĂłn: Web of Science; Scopus.Nanoparticles (NPs) of new fluoride (SrF2 and MgF2) nanocompounds were synthesized by the simple chemical method of precipitation in ethanol. Synthesis of the strontium fluoride (SrF2)-magnesium oxide (MgO) nanocomposite was achieved through the ultrasonic method. These prepared nanopowders were characterized through Fourier transform infrared (FT-IR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Powder X-ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). FT-IR confirmed the purity of the synthesized fluoride NPs by evaluation of the vibrations, and UV-Visible showed the intense absorption peaks of NPs. PXRD analysis indicated the average of particle size, and SEM demonstrated a nearly spherical morphology of the NPs. The antibacterical properties of the nanopowders on Staphylococcus Aureus, Bacillus Subtilis and E. Aklay bacteria were studied, with the strongest effect by the magnesium fluoride (MgF2) NPs and the SrF2-MgO nanocomposite.http://ref.scielo.org/yfr3f
Phase stability of lanthanum orthovanadate at high-pressure
When monoclinic monazite-type LaVO4 (space group P21/n) is squeezed up to 12
GPa at room temperature, a phase transition to another monoclinic phase has
been found. The structure of the high-pressure phase of LaVO4 is indexed with
the same space group (P21/n), but with a larger unit-cell in which the number
of atoms is doubled. The transition leads to an 8% increase in the density of
LaVO4. The occurrence of such a transition has been determined by x-ray
diffraction, Raman spectroscopy, and ab initio calculations. The combination of
the three techniques allows us to also characterize accurately the pressure
evolution of unit-cell parameters and the Raman (and IR)-active phonons of the
low- and high-pressure phase. In particular, room-temperature equations of
state have been determined. The changes driven by pressure in the crystal
structure induce sharp modifications in the color of LaVO4 crystals, suggesting
that behind the monoclinic-to-monoclinic transition there are important changes
of the electronic properties of LaVO4.Comment: 39 pages, 6 tables, 7 figure
A flexible one-pot route to metal/metal oxide nanocomposites
We report a one-pot route to Au/CeO2 nanocomposites. A readily-available biopolymer, sodium alginate, is exploited for controlled formation and stabilisation of gold nanoparticles followed by in situ growth of a sponge-like network of CeO2 nanoparticles. The flexible nature of this method as a general route to mixed metal/metal oxide nanocomposites is also demonstrated
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