Search results for "aqueous solution"
showing 10 items of 1610 documents
Tungstophosphoric acid supported on polycrystalline TiO2 for the photodegradation of 4-nitrophenol in aqueous solution and propan-2-ol in vapour phase
2009
Abstract The present work reports the preparation of samples based on Millennium PC-500 TiO 2 loaded with different amounts of tungstophosphoric acid (up to 30% in weight) and their characterisation by means of different physicochemical techniques: powder X-ray diffraction, N 2 adsorption–desorption at −196 °C, transmission electron microscopy, UV–vis and FT-IR spectroscopies and thermogravimetric analyses. The acidity of samples was evaluated by FT-IR using pyridine as probe molecule, and the catalysts activity was tested for the photodegradation of 4-nitrophenol in aqueous solution and for the photo-oxidation of propan-2-ol in vapour phase. The results show a noticeable improvement (8 and…
Bentonite-ionic liquid composites for Congo red removal from aqueous solutions
2021
Abstract Clay-organic composites have attracted great interest due to their ability to remove various contaminants from wastewater. The surfactants are the most commonly used organic compounds for clay modification. However, cationic surfactants are toxic and can be environmentally hazardous. Ionic liquids are a new promising alternative to the cationic surfactants due to lesser toxicity and appropriate thermal stability. The research aim is to prepare an environmentally friendly new class of clay sorbents modified with ionic liquids for potential applications in wastewater treatment from the textile industry. Imidazolium-based ionic liquids with different lengths of alkyl chains were inter…
In search of layered antimony(III) materials: synthesis and characterization of oxo-antimony(III) catecholate and further studies on antimony(III) ph…
1998
Abstract A new layered oxo-antimony(III) catecholate, [Sb(C6H4O2)]2O, can be obtained by reacting senarmontite with aqueous catechol. The same reaction performed with valentinite, the other allotropic form of Sb2O3, shows an intermediate hydrate that loses water at about 100°C. Both compounds can be obtained from SbPO4 under appropriate experimental conditions. [Sb(C6H4O2)]2O and the hydrated form, which appear to be layered materials, have been characterized by X-ray diffraction, thermogravimetric/differential thermal analyses, and infrared techniques. Preliminary evidence of a reversible intercalation of pyridine into [Sb(C6H4O2)]2O was collected. Taking into consideration the possible us…
Synthesis, crystal structure, thermal and magnetic properties of [Mn(H2O)6][Cu(pdta).2H2O (pdta= 1,3-propylenediamine-N,N,N',N'-tetraacetate
2000
[EN] On mixing concentrated aqueous solutions of pdta, Cu(II) and Mn(II) in the ratio 1:1:1 at pH 4.5, single crystals of the complex [Mn(H2O)6][Cu(pdta)]·2H2O (1) (pdta=1,3-propylenediamine-N,N,N'N'-tetraacetate) were obtained. X-ray structural analysis revealed that in the anion [Cu(pdta)]2- the coordination polyhedron around the Cu(II) ion can be described as a tetragonaly distorted CuN2O4 octahedron, whereas the cation [Mn(H2O)6]2+ can be described as a very regular MnO6 octahedron. Thermogravimetric analysis shows that at 110°C compound 1 loses its eight water molecules yielding the anhydrous compound [MnCu(pdta)] (2). Variable-temperature magnetic susceptibility measurements indicate …
Ecocompatible Halloysite/Cucurbit[8]uril Hybrid as Efficient Nanosponge for Pollutants Removal
2016
Hybrid materials based on halloysite nanotubes (HNT) and cucurbit[8]uril (CB[8]) were prepared with the aim to obtain efficient nanosponges towards hydrocarbons both in liquid and vapor phases. The loading on both HNT surfaces and the hybrid morphology were evidenced by FTIR spectroscopy, thermogravimetric analysis and scanning electron microscopy. In order to highlight the interactions in the hybrid 13C {1H} CP-MAS NMR experiments were performed. The aqueous colloidal stability of HNT/CB[8] was highlighted through ζ potential and dynamic light scattering measurements. The HNT/CB[8] composite was employed as nanosponge to capture aromatic oils in aqueous phase as evidenced by fluorescence e…
Preparation and characterization of a novel chitosan/Al2O3/magnetite nanoparticles composite adsorbent for kinetic, thermodynamic and isotherm studie…
2015
Abstract In this study we developed a novel chitosan/Al 2 O 3 /magnetic iron oxide nanoparticle composite acting as an adsorbent for removing Methyl Orange (MO), a model anionic dye, from aqueous solution. The new adsorbent was characterized by Scanning Electron Microscope (SEM), Thermo Gravimetric Analysis (TGA), Brunauer–Emmett–Teller (BET) specific surface area, Energy Dispersive spectrometer (EDAX), powder X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) methods. The MO removal by the developed adsorbent was investigated using batch adsorption technique and all parameters influencing the removal efficiency such as: dose of adsorbent, pH and initial MO concentr…
A new approach to the synthesis of intermetallic compounds: mild synthesis of submicrometric CoxMy (M = Mo, W; x∶y = 3∶1 and 7∶6) particles by direct…
2002
A simple processing route to cobalt–molybdenum and cobalt–tungsten intermetallics (CoxMy, where M = Mo and W, and x∶y = 3∶1 and 7∶6) has been developed, on the basis of the use of precursors resulting from freeze-drying of aqueous solutions of the appropriate common metal salts. The influence of the preparative variables on the outcomes of this procedure is examined. These compounds are prepared as single phases by thermal reduction of amorphous freeze-dried powders under a hydrogen–argon atmosphere (8% H2), followed by slow cooling of the samples. The materials have been characterised by X-ray powder diffraction, metal analysis, scanning electron microscopy and thermogravimetry under an ox…
Cadmium(II) complexes of cytosine
1990
Complexes of cadmium(II) with cytosine obtained from aqueous or physiological solutions at room temperature are reported. The complexes were characterized by spectroscopic, conductometric,1H-NMR, and13C-NMR measurements and also by thermogravimetry.
Solubility of some calcium-carboxylic ligand complexes in aqueous solution
1994
Insoluble species were identified in the systems Ca(2+)-hemimellitate, Ca(2+)-1,2,3,4-butanetetracarboxylate and Ca(2+)-citrate, and their solubilities were determined in aqueous solution at T = 25 degrees C. Values of pK(s0) were obtained for the species CaLH (L = benzene-1,2,3-tricarboxylate or hemimellitate), Ca(2)L (L = 1,2,3,4-butanetetracarboxylate), CaLH and Ca(3)L(2) (L = citrate), together with their dependence on ionic strength. Solid compounds were also characterized by thermogravimetry. The complex formation in solution for the system Na(+) - and Ca(2+)-hemimellitate was studied too.
Potential Application of Voltammetry of Microparticles for Dating Porcine Blood-based Binding Media used in Taiwanese Architectural Polychromies
2012
A method for dating Hemoglobine-containing archaeological samples using the voltammetry of microparticles is described. This is based on the record of the voltammetric response of such materials attached to paraffin-impregnated graphite electrodes in contact with aqueous acetate buffer. Signals attributable to the Fe(III)/Fe(II) iron couple and their catalytic enhancement in the presence of H(2)O(2) can be correlated, via first-order reaction kinetics, with the time of aging of the samples. The method has been applied to the study and dating of the polychromed architectural decoration of different parts of the architectural complex of the Longshan Temple in Lukang (18(th) century, Taiwan).