نتایج جستجو برای: sio2 pr so3h
تعداد نتایج: 45324 فیلتر نتایج به سال:
Sulfonic acid functionalized SBA-15 as a nanoporous acid catalyst was used in the synthesis of 2-Aryl benzoxazoles 4 by the condensation of 2-aminophenol 1 and benzoyl chlorides 2 under microwave irradiation in solvent free reaction conditions. The advantages of this methodology are good product yields (60-98%), being environmentally benign, short reaction times and easy work up.
Pb(Zr0.52Ti0.48)O3 (PZT) films with (001) orientation were deposited on Pt(111)/Ti/SiO2/Si(100) substrates using pulsed laser deposition. Variation of the laser pulse rate during the deposition of the PZT films was found to play a key role in the control of the microstructure and to change strongly the piezoelectric response of the thin film. The film deposited at low pulse rate has a denser co...
Self-assembled monolayers of alkylsiloxanes supported on poly(dimethylsiloxane) (PDMS) rubber were used as model systems to study the relation between blood compatibility and surface composition. The inner lumen of PDMS tubes were first treated with an oxygen plasma. The resultant oxidized surfaces were post-derivatized by reaction with alkyltrichlorosilanes to form the monolayer films. The alk...
Covalent coupling of sulfonic group (-SO 3H) was attempted on different polymers to evaluate efficacy of this functional group in inducing nucleation of apatite in body environment, and thereupon to design a simple biomimetic process for preparing bonelike apatite-polymer composites. Substrates of polyethylene terephthalate (PET), polycaprolactam (Nylon 6), high molecular weight polyethylene (H...
Pristine multiwall carbon nanotubes [MWCNTs] have been functionalized with various groups (-COOH, -SO3H, -PO3H2) using different single- and double-step chemical routes. Various chemical treatments were given to MWCNTs using hydrochloric, nitric, phosphoric, and sulphuric acids, followed by a microwave treatment. The effect of the various chemical treatments and the dispersion using a surfactan...
Novel hierarchical Cd4SiS6/SiO2 based heterostructure nanowire arrays were fabricated on silicon substrates by a one-step thermal evaporation of CdS powder. The as-grown products were characterized using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. Studies reveal that a typical hierarchical Cd4SiS6/SiO2 heterostructure nanowire is composed of a single c...
The hollow CuO@SiO2 spheres with a mean diameter of 240 nm and a thin shell layer of about 30 nm in thickness was synthesized using an inorganic SiO2 shell coating on the surface of Cu@C composite that was prepared by a two-step hydrothermal method. The obtained hollow CuO@SiO2 spheres were characterized by ICP-AES, nitrogen adsorption-desorption, SEM, TEM, XRD, H2-TPR, CO-TPR, CO-TPD and NO-TP...
Post-grafting methodologies were used to prepare aryl-organosulfonic acid functionalized silica nanoparticles (SO3H-aryl-SiO2NPs) as highly active heterogeneous catalysts for catalytic esterification of free fatty acids (FFA) and levulinic (LA), aldol condensation furfural with 3-methylfuran, well known renewable feedstocks biodiesel fuel additives production. The chemical structural characteri...
The conversion of biomass resources into high-value fuels and chemicals using thermochemical methods has become an attractive method energy utilization. In this study, natural minerals were used as raw materials; the acidic sites introduced by ball-milling modification, aldol condensation reaction biomass-based cyclopentanone molecule was carried out under solvent-free conditions. It found that...
Major and trace elements (Na, Mg, Al, Si, P, K, Ca, Ti, Mn, Fe, Rb, Sr, Y, Zr, La, Ce, Pr, Nd, Sm, Gd, Dy, Th and U) in igneous rocks were assayed with fused lithium borate glass beads using X-ray fluorescence spectrometry. Low dilution glass beads, which had a 1:1 sample-to-flux ratio, were prepared for determination of rare earth elements. Complete vitrification of 1:1 mixture required heatin...
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