in the present work, a new kind of alumina-based adsorbent with high selectivity and stability and efficient adsorption was prepared. alumina was coated with an oxazolone azo dye, 2-(4-{2-[4-(dimethylamino) phenyl]-1-diazenyl}phenyl)-4-[1-phenyl methylidene]-5(4h)-oxazolone, and then used for preconcentration of trace amounts of palladium. the analytical procedure involved the complex formation...

The influence of NaNO2, HNO3 and H2SO4 on the structure and morphology of gamma-alumina was investigated by XRD, BET, SEM and FT-IR spectroscopy. Selected amounts of NaNO2, HNO3 and H2SO4 were added to a solution of aluminum isopropoxide (as a precursor for the boehmite synthesis). The boehmite samples were calcined at 350 and 600 ℃ to form the semi-crystalline high surface area gamma-Al2O3. Th...

This paper describes the use of several characterization methods to examinealumina nanotubule membranes that have been modified with specific silanes. The functionof these silanes is to alter the transport properties through the membrane by changing thelocal environment inside the alumina nanotube. The presence of alkyl groups, either long(C18) or short and branched (isopropyl) hydrocarbon chai...

Al2O3:SiOC nanocomposites were synthesized by thermal treatment of fumed alumina nanoparticles modified by phenyltrimethoxysilane. The effect of annealing temperature in inert ambient on structure and photoluminescence of modified alumina powder was studied by IR spectroscopy as well as photoluminescence spectroscopy with ultraviolet and X-ray excitation. It is demonstrated that increase of ann...

A mechanism of the solute retention in gas-liquid chromatography has been studied in the nonpolar hydrocarbon solute-polar stationary liquid phase system. N,N,N',N'-tetrakis(2-hydroxyethyl)ethylene diamine (THEED) was used as a polar stationary liquid phase. A dependence of the retention volume of the solutes and of the specific surface area of the liquid-coated, modified alumina upon the liqui...

Catalytic oxidation of thiourea has been studied at alumina modified Pt electrode using cyclic voltammetry. The results indicate the suitability of alumina modified Pt electrode for voltammetric determination of thiourea. The catalytic peak currents are linearly dependent on the thiourea concentration in the range 2.5 × 10 – 7.0 × 10 M. The usefulness of the method was tested in determination o...

Superhydrophobic nanoporous anodic aluminum oxide (alumina) surfaces were prepared using treatment with vapor-phase hexamethyldisilazane (HMDS). Nanoporous alumina substrates were first made using a two-step anodization process. Subsequently, a repeated modification procedure was employed for efficient incorporation of the terminal methyl groups of HMDS to the alumina surface. Morphology of the...

A new method to stabilize and functionalize surfaces for surface-enhanced Raman spectroscopy (SERS) is demonstrated. Atomic layer deposition (ALD) is used to deposit a sub-1-nm alumina layer on silver film-over-nanosphere (AgFON) substrates. The resulting overlayer maintains and stabilizes the SERS activity of the underlying silver while presenting the surface chemistry of the alumina overlayer...