Search results for "hydrogen"
showing 10 items of 4254 documents
Epoxidation of Olefins with a Silica-Supported Peracid in Supercritical Carbon Dioxide under Flow Conditions
2012
Anhydrous 2-percarboxyethyl-functionalized silica (2b), a recyclable supported peracid, is a suitable reagent to perform the epoxidation of alkenes 1 in supercritical carbon dioxide at 250 bar and 40 °C under flow conditions. This procedure simplifies the isolation of the reaction products and uses only carbon dioxide as a solvent under mild conditions. The solid reagent 2b can be easily recycled by a reaction with 30% hydrogen peroxide in an acid medium.
Controlled Self-Assembly of Electron Donor Nanotubes
2009
We employ a combination of urea-urea hydrogen bonds and pi-pi stacking interactions to obtain soluble self-assembled nanotubes decorated with electron-donor TTF derivatives on the periphery. We have investigated the structure and stability of the nanotubes with a combination of experiments and high-level DFT calculations. We also demonstrate that the association process can be controlled by changes in the hydrogen-bonding ability of the solvent and electrochemically.
Dispersive solid-phase extraction based on oleic acid-coated magnetic nanoparticles followed by gas chromatography-mass spectrometry for UV-filter de…
2011
Abstract A sensitive analytical method to concentrate and determine extensively used UV filters in cosmetic products at (ultra)trace levels in water samples is presented. The method is based on a sample treatment using dispersive solid-phase extraction (dSPE) with laboratory-made chemisorbed oleic acid-coated cobalt ferrite (CoFe 2 O 4 @oleic acid) magnetic nanoparticles (MNPs) as optimized sorbent for the target analytes. The variables involved in dSPE were studied and optimized in terms of sensitivity, and the optimum conditions were: mass of sorbent, 100 mg; donor phase volume, 75 mL; pH, 3; and sodium chloride concentration, 30% (w/v). After dSPE, the MNPs were eluted twice with 1.5 mL …
Design, characterization and evaluation of hydroxyethylcellulose based novel regenerable supersorbent for heavy metal ions uptake and competitive ads…
2017
Abstract Hydroxyethylcellulose succinate-Na (HEC-Suc-Na) was designed and evaluated for removal of some heavy metal ions from aqueous solution. Pristine sorbent HEC-Suc-Na was thoroughly characterized by FTIR and solid-state CP/MAS 13C NMR spectroscopy, SEM-EDS and zero point charge analyses. Langmuir isotherm, pseudo second order kinetic and ion exchange models provided best fit to the experimental data of sorption of metal ions. Maximum sorption capacities of supersorbent HEC-Suc-Na for sorption of heavy metal ions from aqueous solution as calculated by Langmuir isotherm model were found to be 1000, 909.09, 666.6, 588 and 500 mg g−1 for Pb(II), Cr(VI), Co(II), Cu(II) and Ni(II), respectiv…
CCDC 233284: Experimental Crystal Structure Determination
2004
Related Article: A.L.Thompson, A.E.Goeta, J.A.Real, A.Galet, M.C.Munoz|2004|Chem.Commun.||1390|doi:10.1039/b403179b
CCDC 233282: Experimental Crystal Structure Determination
2004
Related Article: A.L.Thompson, A.E.Goeta, J.A.Real, A.Galet, M.C.Munoz|2004|Chem.Commun.||1390|doi:10.1039/b403179b
CCDC 233283: Experimental Crystal Structure Determination
2004
Related Article: A.L.Thompson, A.E.Goeta, J.A.Real, A.Galet, M.C.Munoz|2004|Chem.Commun.||1390|doi:10.1039/b403179b
CCDC 233281: Experimental Crystal Structure Determination
2004
Related Article: A.L.Thompson, A.E.Goeta, J.A.Real, A.Galet, M.C.Munoz|2004|Chem.Commun.||1390|doi:10.1039/b403179b
CCDC 1419794: Experimental Crystal Structure Determination
2016
Related Article: Marta Feliz and Francisco Estevan|2016|Eur.J.Inorg.Chem.||92|doi:10.1002/ejic.201501085
CCDC 1037192: Experimental Crystal Structure Determination
2016
Related Article: Riccardo Gava, Andrea Olmos, Bárbara Noverges, Teresa Varea, Eleuterio Álvarez, Tomás R. Belderrain, Ana Caballero, Gregorio Asensio, and Pedro J. Pérez|2015|ACS Catalysis|5|3726|doi:10.1021/acscatal.5b00718