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Adsorción, Cinética de adsorción, Isoterma de adsorción, Solución acuosa, Carbón activado, and Monolito.

En esta investigación se obtuvo carbón activado por activación química con ácido fosfórico (H3PO4) al 85% a partir de material cáscara de Coco, el cual fue conformado en estructuras rígidas de geometrías Monolíticas, especificamente geometrías disco y “panal de abejas” o honeycomb. El carbón activado obtenido fue empleado en la remoción de fenol en soluciones acuosas con concentraciones iniciales entre 10 y 100 mg/L en sistemas batch a temperatura ambiente. Las determinaciones se realizaron mediante espectrofometría UV-Visible. Se analizó el fenomeno de adsorción desde el punto de vista cinético.Tambíen fueron estudiadas las isotermas, empleando diversos modelos. Los modelos de isoterma de adsorción empleados presentaron muy buena correlación con los datos experimentales obtenidos, excepto en la geometria honeycomb con el modelo de Redlich-Paterson, las gráficas obtenidas permiten describir el proceso de adsorción como un proceso de formación de monocapa en la superficie del adsorbente, debido a la forma caracteristica de Isoterma tipo Langmuir presentada para prácticamente todos los modelos de isoterma.

SESAME oil, AQUEOUS solutions, OIL & fat extraction, EDIBLE fats & oils, ENHANCED oil recovery, SOLVENT extraction, OXIDATION, and HEALTH

Research into the production of white sesame oil by aqueous extraction has been promoted because of concerns about the environment, health, and cost. The advanced aqueous method using a 1.95:10 liquid-to-raw material ratio, which was finally developed in this study, recovered 96.06% white sesame oil and produced de-oiled meal with high quality (3.98% residual oil content). The acid value and peroxide value of the oil produced were quite low at 0.19 mg KOH/kg and < 3.25 mmol/kg, respectively, which were better than the values required by the Chinese national standard for first class edible sesame oils and oils produced by hexane extraction. No wastewater was discharged during the extraction of white sesame oils by an aqueous salt solution. The protein rich de-oiled meal may be a good material for making protein isolate with high purity (e.g. > 90%). It can also be a nutritious ingredient or raw material for producing many food products. [ABSTRACT FROM AUTHOR]

General chemistry, physical chemistry, Chimie générale, chimie physique, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Sonochimie, Ultrasonic chemistry, Benzène(nitro), Dégradation, Degradation, Degradación, Ozonation, Ozonization, Ozonización, Ozone, Ozono, Radical hydroxyle, Hydroxyl radicals, Réaction catalytique, Catalytic reaction, Reacción catalítica, Solution aqueuse, Aqueous solution, Solución acuosa, Sonochimie, Sonochemistry, Sonoquímica, Ultrason, Ultrasound, Ultrasonido, Catalytic ozonation, Hydroxyl radical (·OH), Multiple-field ultrasound, and Nitrobenzene

The synergetic effect between ozone and ultrasound can enhance the degradation of nitrobenzene and removal efficiency of TOC in aqueous solution, and the degradation of nitrobenzene follows the mechanism of hydroxyl radical (.OH) oxidation. Under the same total ultrasonic power input condition, the degradation rate of nitrobenzene (kNB), the volumetric mass transfer coefficient of ozone (kLa), and the initiation rate of .OH (k.OH) increases with introduction of additional ultrasonic field (1-4) in the process of ozone/ultrasound. The increasing amount of ultrasonic fields accelerates the decomposition of ozone, leading to the rapid appearance of the maximum equilibrium value and the decrease in the accumulation concentration of ozone in aqueous solution with the increasing reaction time. The increase in mass transfer of gaseous ozone dissolved into aqueous solution and the acceleration in the decomposition of ozone in aqueous solution synchronously contribute to the increase of kLa. The investigation of mechanism confirms that the increasing amount of ultrasonic fields yields the increase in cavitation activity that improves the mass transfer and decomposition of ozone, resulting in acceleration of .OH initiation, which determines the degradation of nitrobenzene in aqueous solution.

General chemistry, physical chemistry, Chimie générale, chimie physique, Environment, Environnement, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Composé de métal de transition, Transition element compounds, Acide, Acids, Acido, Aldéhyde, Aldehyde, Aldehído, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Oxyde de titane, Titanium oxide, Titanio óxido, Photocatalyse, Photocatalysis, Fotocatálisis, Protection environnement, Environmental protection, Protección medio ambiente, Rayonnement solaire, Solar radiation, Radiación solar, Solution aqueuse, Aqueous solution, Solución acuosa, Picolinic acid, Pyridinecarboxy aldehydes, Sacrificial photocatalysis, Solar chemical productions, and Vitamin 83

The conversion of pyridinemethanol isomers into their respective aldehydes and carboxylic acids has been attempted in aqueous solution through sacrificial TiO2 photocatalysis in the presence of cupric ions, at ambient temperature, under acidic and deaerated conditions, using artificial sunlight. The presence of a nitrogen atom in the aromatic ring, with respect to benzylic alcohol and its derivatives, affects the photocatalytic behavior of the substrate. The influence of both pH and temperature has also been investigated. The position of the methanolic group on the aromatic ring leads to slight changes in the selectivities, yields and the oxidation rates. Under the adopted conditions, the yields and selectivities to aldehydes are always higher than those of the respective carboxylic acids. The photocatalytic process can be carried out in consecutive copper reduction/oxidation steps in order to reuse the catalyst. In this way greater yields and selectivities to the desired product than 60% can be achieved. The process can be considered interesting as it concerns the eco-green production of valuable fine chemicals, using water as a solvent at ambient conditions, a cheap heterogeneous catalyst and solar radiation.

General chemistry, physical chemistry, Chimie générale, chimie physique, Environment, Environnement, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Composé de métal de transition, Transition element compounds, Azote, Nitrogen, Nitrógeno, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Dégradation, Degradation, Degradación, Oxyde de titane, Titanium oxide, Titanio óxido, Photocatalyse, Photocatalysis, Fotocatálisis, Protection environnement, Environmental protection, Protección medio ambiente, Solution aqueuse, Aqueous solution, Solución acuosa, Diphenhydramine, Escherichia coli, and Nitrogen modified TiO2

Nitrogen modified TiO2 samples were prepared by grinding the benchmark TiO2 photocatalyst (P25, Evonik Degussa Corporation) with different amounts of urea and applying calcination temperatures between 340 and 420°C. Several characterization techniques, including X-ray photoelectron spectroscopy (XPS), N2 porosimetry, X-ray diffraction (XRD), scanning electronic microscopy (SEM), and diffuse reflectance UV-vis spectroscopy (UV-DRS), were used to obtain information about the morphology, crystalline phases of TiO2 and chemical binding of nitrogen. Nitrogen modification did not affect the crystalline phase of TiO2 as far as XRD analysis concerns; on the other hand the modified materials developed an absorption in the visible part of the electromagnetic spectrum. The material with a urea:TiO2 weight ratio of 1:2, calcined at 380°C, exhibited the highest photocatalytic activity under visible light illumination (λ > 430 nm), towards degradation of diphenhydramine, an emerging water pollutant of pharmaceutical origin. The measured band gap energy of the material was 2.99 eV, which is in-line with observed optical absorption properties. In addition, this photocatalyst was also the most efficient for complete inactivation of Escherichia coli in aqueous solution when ultraviolet radiation (λ = 365 nm) was used. From the XPS analysis on the chemical states of this photocatalyst it is concluded that nitrogen is interstitial to the TiO2 structure.

General chemistry, physical chemistry, Chimie générale, chimie physique, Environment, Environnement, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Acide carboxylique, Carboxylic acid, Acido carboxílico, Métal transition, Transition metal, Metal transición, Acide acétique, Acetic acid, Acético ácido, Alliage, Alloys, Aleación, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Photocatalyse, Photocatalysis, Fotocatálisis, Protection environnement, Environmental protection, Protección medio ambiente, Solution aqueuse, Aqueous solution, Solución acuosa, Structure locale, Local structure, Estructura local, Titane, Titanium, Titanio, Vanadate, Vanadates, Vanadato, Vanadium, Vanadio, Photocatalyseur, Photocatalyst, Anodization, Titanium alloy, and Visible light response

Anodization of Ti-6Al-4V alloy in acetic acid aqueous solution resulted in the formation of amorphous oxide on its surface; the amorphous oxide transformed into crystalline oxide primarily consisting of anatase TiO2 by annealing. The annealed anodic oxide, especially those anodized in 1-2 mol L-1 acetic acid aqueous solution, could photocatalytically decompose acetaldehyde under visible light illumination. X-ray photoelectron spectroscopy, Raman spectroscopy, and X-ray absorption near-edge structure spectroscopy analyses showed that the vanadium is pentavalent and exists in an oxygen-tetragonal structure composed of VO43- units. When the vanadate absorbs visible light, the excited electrons move into the conduction band of anatase TiO2 so that recombination with holes was restricted. As a result, the anodic oxide exhibited superior photocatalytic activity under visible light illumination.

Food science technology, Sciences technologies alimentaires, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Toxicologie, Toxicology, Toxicologie alimentaire, Food toxicology, Comportement, Behavior, Conducta, Glucide, Carbohydrate, Glúcido, Hydratation, Hydration, Hidratación, Partiel, Partial, Parcial, Qualité, Quality, Calidad, Saveur, Taste, Sabor, Sodium, Sodio, Solution aqueuse, Aqueous solution, Solución acuosa, Viscosité, Viscosity, Viscosidad, Volume, Volumen, Apparent specific volume, Partial molar volume, Saccharide, Sodium gluconate, Taste quality, and Viscosity B-coefficient

Thermodynamic and transport properties are very useful in providing valuable information regarding the hydration characteristics of saccharides and play a pivotal role in the study of taste behaviour of saccharides in mixed aqueous solutions. The effects of sodium gluconate and other sodium salts on the hydration behaviour and the basic taste quality of saccharides have been studied from measured apparent molar volumes (V2.φ,). partial molar volumes (V°2) at infinite-dilution, and viscosity B-coefficients, of eight monosaccharides, six disaccharides and two trisaccharides in (0.25, 0.50, 1.00 and 1.50) mol kg―1 aqueous sodium gluconate solutions over a temperature range of (288.15―318.15) K and at atmospheric pressure. Partial molar volumes of transfer (ΔtV°2) and viscosity B-coefficients of transfer (ΔtB) of saccharides and other parameters such as isobaric expansion coefficients, interaction coefficients (using McMillan-Mayer theory), and dB/dT parameters have also been determined and discussed in terms of solute (saccharide)-cosolute (sodium gluconate) interactions.

General chemistry, physical chemistry, Chimie générale, chimie physique, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Sonochimie, Ultrasonic chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Métal transition, Transition metal, Metal transición, Broyeur boulet, Ball mill, Molino bolas, Ferrite, Ferrita, Ferrites, Ferritas, Hydroxyle, Hydroxyl, Hidroxilo, Ion, Ions, Ión, Nanoparticule, Nanoparticle, Nanopartícula, Nickel, Niquel, Solution aqueuse, Aqueous solution, Solución acuosa, Sonochimie, Sonochemistry, Sonoquímica, Synthèse, Synthesis, Síntesis, Ultrason, Ultrasound, Ultrasonido, Ball milling, Hydroxyl radicals, Nickel ferrite, and Ultrasonic wave

Ball milling experiments were conducted with and without ultrasound wave assistance in deionized water using NiCO3·2Ni(OH)2·4H2O as raw materials. In the reaction process of NiFe2O4 prepared by ultrasound-assisted aqueous solution ball milling, some influencing factors including raw materials, ultrasonic frequency, ball to powder ratio and liquid level were changed. Samples were characterized by X-ray diffraction, fluorescence measurements and electroconductivity detections. The results indicate that more hydroxyl radicals and ions can be generated under the coupling effect of ultrasonic and ball milling. The fluorescence measurements and electroconductivity detections also reflect the reaction speed, allowing for optimal parameters to be determined.

Electrical engineering, Electrotechnique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Catalyseurs: préparations et propriétés, Catalysts: preparations and properties, Electrochimie, Electrochemistry, Divers (électroosmose, électrophorèse, électrochromisme, électrocristallisation, ...), Miscellaneous (electroosmosis, electrophoresis, electrochromism, electrocrystallization, ...), Composé hydrosoluble, Water soluble compound, Compuesto hidrosoluble, Cuivre II Composé, Copper II Compounds, Cobre II Compuesto, Dégagement gazeux, Gas release, Desprendimiento gaseoso, Eau, Water, Agua, Electrocatalyse, Electrocatalysis, Electrocatálisis, Electrocatalyseur, Electrocatalysts, Hydrogène, Hydrogen, Hidrógeno, Oxydation, Oxidation, Oxidación, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Réduction chimique, Chemical reduction, Reducción química, Solution aqueuse, Aqueous solution, Solución acuosa, Hydrogen evolution, Water oxidation, Water reduction, and Water soluble copper(II) electrocatalyst

Splitting water is a key challenge in the production of chemical fuels from electricity. Although several catalysts have been developed for these reactions, substantial challenges remain towards the ultimate goal of an efficient, inexpensive and robust electrocatalyst. Until now, there is as yet no report on both water oxidation and reduction by identical catalyst. Reported here is the first soluble copper-based catalyst, Cu(Me2oxpn)Cu(OH)2] 1 (Me2oxpn: N,N'-bis(2,2'-dimethyl-3-aminopropyl)oxamido) for both electrolytic water oxidation and reduction. Water oxidation occurs at an overpotential of 636 mV vs SHE to give O2 with a turnover frequency (TOF) of ∼2.14 s-1. Electrochemical studies also indicate that 1 is a soluble molecular species, that is among the most rapid homogeneous water reduction catalysts, with a TOF of 654 mol of hydrogen per mole of catalyst per hour at an overpotential of 789 mV vs SHE (pH 7.0). Sustained water reduction catalysis occurs at glassy carbon (GC) to give H2 over a 32 h electrolysis period with 95% Faradaic yield and no observable decomposition of the catalyst.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Préparation, cinétique, thermodynamique, mécanisme et catalyseurs, Preparation, kinetics, thermodynamics, mechanism and catalysts, Polymères à propriétés spéciales, Polymers with particular properties, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Propriété biologique, Biological properties, Propiedad biológica, Amine copolymère, Amine copolymer, Amina copolímero, Cellule tumorale, Tumor cell, Célula tumoral, Ciblage, Targeting, Blancado, Copolymère bigreffé, Bigraft copolymer, Copolímero biinjertado, Copolymère biséquencé, Diblock copolymer, Copolímero bisecuencia, Copolymère soufre, Sulfur copolymer, Copolímero azufre, Copolymérisation radicalaire, Radical copolymerization, Copolimerización radical, Cytotoxicité, Cytotoxicity, Citotoxicidad, DNA, Disulfure organique, Organic disulfide, Disulfuro orgánico, Ethylène oxyde copolymère, Ethylene oxide copolymer, Etileno óxido copolímero, Ethylène oxyde polymère, Ethylene oxide polymer, Etileno óxido polímero, Etude expérimentale, Experimental study, Estudio experimental, Greffage, Grafting, Injerto, Lignée HeLa, Hela cell line, Célula HeLa, Macromère, Macromer, Macrómero, Micelle mixte, Mixed micelle, Micela mixta, Molécule asymétrique, Asymmetric molecule, Molécula asimétrica, Méthacrylate copolymère, Methacrylate copolymer, Metacrilato copolímero, Méthacrylique acide ester, Methacrylic acid esters, Plasmide, Plasmid, Plasmido, Polymère vecteur, Control release polymer, Polímero vector, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Polymérisation transfert atome, Atom transfer polymerization, Polimerización transferencia atomo, Potentiel électrocinétique, Electrokinetic potential, Potencial electrocinético, Préparation, Preparation, Preparación, Rayon hydrodynamique, Hydrodynamic radius, Radio hidrodinámico, Réaction successive, Successive reaction, Reacción consecutiva, Solution aqueuse, Aqueous solution, Solución acuosa, Solution micellaire, Micellar solution, Solución micelar, Transfection, Transfección, Transfert chaîne, Chain transfer, Transferencia en cadena, Trithiocarbonate organique, Organic trithiocarbonate, Tritiocarbonato orgánico, Vecteur médicament, Drug carrier, Vector medicamento, Copolymère réductible, Folique dérivé copolymère, Groupe méthacryloyle, Méthacrylate de 2-[diméthylamino]éthyle copolymère, Polyplexe, Polyplex, Ptéridine dérivé copolymère, biodegradable, brush block copolymers, gene delivery, reductive milieu, and stimuli-responsive polymers

Novel neutral-cationic brush block copolymer, poly[oligo(ethylene glycol) monomethyl ether methacrylate-co-folic acid methacrylate]-b-poly[2-(2-(2-(2-bromo-2-methylpropanoyloxy)-ethyl) disulfanyl) ethyl methacrylate-g-2-dimethylaminoethyl methacrylate], P(OEGMA-co-FAMA)-b-P(BSSMA-g-PDMAEMA), is synthesized via consecutive controlled radical polymerizations. Containing disulfide linkages bridging backbone and side chains in the cationic brush block and cancer cell-targeting ligands (folic acid) in the neutral hydrophilic block, the diblock copolymer is employed as a tumor-targeted redox-responsive degradable nonviral gene delivery vector. P(OEGMA-co-FAMA)-b-P(BSSMA-g-PDMAEMA) brush block copolymers can condense plasmid DNA (pDNA) efficiently via the formation of electrostatic polyplex micelles. Under reductive milieu, pDNA can be released due to the cleavage of disulfide linkages and accordingly pDNA-binding cationic PDMAEMA side chains. In addition, the brush block copolymer exhibits low cytotoxicity and the corresponding polyplex micelles show relatively high gene transfection efficiency.

Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Hydrologie. Hydrogéologie, Hydrology. Hydrogeology, Hydrogéologie, Hydrogeology, Géologie de l'ingénieur et de l'environnement. Géothermie, Engineering and environment geology. Geothermics, Pollution, géologie de l'environnement, Pollution, environment geology, Aquifère, aquifers, Arsenic, arsenic, Arsénico, Arséniate, arsenates, Arseniato, Arsénite, arsenites, Arsenito, Contamination, contamination, Contaminación, Eau souterraine, ground water, Agua subterránea, Etude expérimentale, experimental studies, Fer, iron, Hierro, Gestion ressource eau, water resource management, Gestión recurso agua, Microorganisme, microorganisms, Microorganismo, Pollution, pollution, Polución, Solution aqueuse, aqueous solutions, Solución acuosa, Stratégie, strategy, Estrategia, Transformation, transformations, Transformación, Zone rurale, rural areas, Zona rural, Bangladesh, Biotransformation, Cow dung, Microorganisms, and Sludge

With increasing use of arsenic (As) removal units for treatment of As-contaminated groundwater in rural Bangladesh, concerns have been raised regarding safe disposal of the As-rich wastes from such units and possible contamination of the environment. In the absence of any clear guideline for safe disposal of wastes generated from As removal units, the wastes are usually disposed of in the open environment, often on cow dung beds in the backyard. Short term (up to 6 weeks) batch experiments performed in this study suggest that bio-chemical (e.g., bio-methylation) processes in the presence of only fresh cow dung may lead to a significant removal of As, both from aqueous solution and As-rich treatment wastes. Arsenic removal appears to increase with decreasing As to cow dung weight ratio. This study also suggests that arsenate transforms to arsenite before removal from aqueous As solution in the presence of cow dung. In most cases majority of As removal takes place during first few days. Removal of As under cap-open (to facilitate aerobic condition) and cap-closed conditions (to facilitate aerobic condition) were found to be similar. No significant variation was observed in the removal As from aqueous solution and from treatment wastes (As bound to iron solids). This study concludes that disposal of As-rich treatment wastes to cow dung pits could be an effective option of As sludge disposal and management in rural areas of Bangladesh.

Energy, Énergie, Environment, Environnement, Pollution, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Préparation, cinétique, thermodynamique, mécanisme et catalyseurs, Preparation, kinetics, thermodynamics, mechanism and catalysts, Polycondensation, Pollution, Additif, Additive, Aditivo, Angle contact, Contact angle, Angulo contacto, Chargement, Loading, Cargamento, Couche mince, Thin film, Capa fina, In situ, Matériau composite, Composite material, Material compuesto, Microscopie force atomique, Atomic force microscopy, Microscopía fuerza atómica, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Nanoparticule, Nanoparticle, Nanopartícula, Osmose, Osmosis, Perméabilité eau, Water permeability, Permeabilidad agua, Perméabilité liquide, Liquid permeability, Permeabilidad líquido, Polycondensation interfaciale, Interfacial polymerization, Policondensación interfacial, Rejet, Rejection, Rechazo, Solution aqueuse, Aqueous solution, Solución acuosa, Spectrométrie FTIR, Fourier-transformed infrared spectrometry, Espectrometría FTIR, Forward osmosis, Polyamide, Silica nanoparticles, and Thin-film nanocomposite membrane

This paper presents polyamide nano-composite membrane containing silica nanoparticles (TFN) synthesized via in situ interfacial polymerization for the forward osmosis (FO) application. Different concentrations of silica nanoparticles (0.01, 0.05 and 0.1% w/v) were added to the aqueous solution as additive to improve the FO membrane performance. The prepared membranes were characterized by ATR-FTIR, SEM, AFM and hydrophilicity measurement. The structure of nanocomposite layer synthesized by interfacial polymerization was characterized by FTIR spectroscopy. The FTIR peaks confirmed the presence of polyamide layer with SiO2 nanoparticles. The morphological studies showed that the SiO2 nanoparticles were effectively attached to the FO membrane surface. The contact angle measurements showed that the hydrophilicity of FO membranes was improved with increasing SiO2 in the aqueous solution. The FO performance was measured using 10 mM NaCl solution as feed solution and 2 M NaCl solution as draw solution in both orientations. The TFN membranes showed higher water permeability and better salt rejection in the range of 0.01―0.1 wt.% silica loading in comparison with the TFC membrane. The water flux of the TFN membrane reached to a maximum of 36 ± 2 L/m2 h which is nearly 2 times as high as that of the TFC membrane and it was found that the membrane modified with 0.05 w/v.% silica nanoparticles showed the highest salt rejection (90 ± 3%).

Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Hydrologie. Hydrogéologie, Hydrology. Hydrogeology, Hydrogéologie, Hydrogeology, Géologie de l'ingénieur et de l'environnement. Géothermie, Engineering and environment geology. Geothermics, Pollution, géologie de l'environnement, Pollution, environment geology, Cénozoïque, Cenozoic, Cenozoico, Phanérozoïque, Phanerozoic, Fanerozoico, Phyllosilicate, sheet silicates, Filosilicato, Quaternaire sup, upper Quaternary, Cuaternario sup, Quaternaire, Quaternary, Cuaternario, Silicate, silicates, Silicato, Adsorption, adsorption, Adsorción, Analyse chimique, chemical analysis, Análisis químico, Aquifère peu profond, shallow aquifers, Arsenic, arsenic, Arsénico, Atmosphère, atmosphere, Atmósfera, Atténuation, attenuation, Atenuación, Densité, density, Densidad, Dimension grain, grain size, Dimensión grano, Eau souterraine, ground water, Agua subterránea, Equation Langmuir, Langmuir equation, Etude expérimentale, experimental studies, Fluctuation, fluctuations, Fluctuación, Holocène, Holocene, Holoceno, Irrigation, irrigation, Irrigación, Isotherme, isotherms, Isothermo, Mica, mica, Niveau piézométrique, water table, Oxydation, oxidation, Oxidación, Oxygène, oxygen, Oxígeno, PH, pH, Pléistocène, Pleistocene, Profondeur, depth, Profundidad, Solution aqueuse, aqueous solutions, Solución acuosa, Subsurface, subsurface, Transport, transport, Transporte, Aquifer sediments, Distribution coefficient, and Isotherm

The transport of arsenic (As) in groundwater is known to be considerably controlled by the adsorption behavior of aquifer sediments and changes in subsurface redox conditions. Here we report wet chemical analyses of AS(III) adsorption onto oxidized, low As containing Holocene aquifer sediments from West Bengal, India. Batch experiments in an open laboratory atmosphere show that the slow removal of As(III) from aqueous solution is a resulting effect of adsorption and oxidation which is not significantly influenced by the changes in pH (6.0―9.1). The isotherm data were fitted with Freundlich and Langmuir equations and maximum adsorption density (Γmax ≈ 0.40 mmol kg―1) obtained is lower than that for As(V) at pH 7.5 (0.95 mmol kg―1). The estimated distribution coefficient maxima (Kdmax) values are within the ranges of Kd values previously reported in case of Holocene aquifer sediments of West Bengal, India and Bangladesh. The low adsorption capacity of oxidized Holocene aquifer sediments in this study compared to oxidized Pleistocene sediments of Bangladesh is attributed to coarser grain sizes and low abundance of Fe-oxyhydroxides and micas which act as a potential sink of As. This study has important implications for As(III) attenuation and transport in the shallow aquifers (especially around the zone of 'maximum' water table fluctuations, i.e., 10―20 m depth below ground surface) when oxygen-depleted (anoxic) Holocene aquifers get in contact with oxygen (e.g., by irrigation/groundwater drawdown) and also for predicting possible future risk associated with its transport from shallow aquifers to present day low-As containing deeper aquifers of West Bengal, India.

Electronics, Electronique, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Méthodes de dépôt de films et de revêtements; croissance de films et épitaxie, Methods of deposition of films and coatings; film growth and epitaxy, Techniques de revêtement par pulvérisation, Spray coating techniques, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Dispositifs optoélectroniques, Optoelectronic devices, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Absorbeur, Absorber, Absorbente, Absorption 2 photons, Two photon absorption, Absorción 2 fotones, Assemblage circuit intégré, Integrated circuit bonding, Cellule solaire, Solar cell, Célula solar, Chalcopyrite, Calcopirita, Chalkopyrit, Couche mince, Thin film, Capa fina, Duennschicht, Couche tampon, Buffer layer, Capa tampón, Diffraction RX, X ray diffraction, Difracción RX, Roentgenbeugung, Dépôt projection, Spray coating, Depósito proyección, Spritzbeschichten, Effet température, Temperature effect, Efecto temperatura, Temperatureinfluss, Gain, Ganancia, Indium, Indio, Matériau absorbant, Absorbent material, Material absorbente, Matériau cristallin, Crystalline material, Material cristalino, Recuit mise en solution, Solution heat treatment, Recocido disolución, Loesungsgluehen, Relation ordre, Ordering, Relación orden, Site cristallographique, Crystallographic site, Sitio cristalográfico, Solution aqueuse, Aqueous solution, Solución acuosa, Waesserige Loesung, Spectre Raman, Raman spectrum, Espectro Raman, Spectrométrie Raman, Raman spectrometry, Espectrometría Raman, Spectrométrie dispersive, Dispersive spectrometry, Espectrometría dispersiva, Stoechiométrie, Stoichiometry, Estequiométría, Stoechiometrie, Sulfure d'indium, Indium sulfide, Indio sulfuro, Indiumsulfid, Technologie CSP, Chip scale packaging, Température substrat, Substrat temperature, Temperatura substrato, Température superficielle, Surface temperature, Temperatura superficial, Oberflaechentemperatur, Thiourée, Thiourea, Tiourea, 7830N, 8460J, Cellule solaire à bande intermédiaire, Intermediate band solar cell, In2S3, Pyrolyse par projection, Spray pyrolysis, Chemical spray pyrolysis, EDX, Raman spectroscopy, and XRD

Indium sulfide (In2S3) thin films are of interest as buffer layers in chalcopyrite absorber based solar cells; and as media providing two-photon absorption for intermediate-band solar cells. We investigated the suitability of chemical spray pyrolysis (CSP) for growing In2S3 thin films in a structural order where indium atoms are preferentially in the octahedral sites. We sprayed aqueous or alcoholic solutions of indium chloride (InCl3) and thiourea (SC(NH2)2) precursors onto a substrate with surface temperatures (Ts) of 205, 230, 275 and 320 °C. The as-deposited films grown from aqueous solutions were annealed in 5% H2S containing atmosphere at 500 °C. We used Raman spectroscopy, X-ray diffraction and Energy Dispersive X-ray spectroscopy to evaluate the effect of growth temperature and the effect of annealing on the film structure and stoichiometry. The use of alcoholic solvent instead of aqueous allows us to use much lower Ts while preserving the quality of the β-In2S3 films obtained. Similarly, films with increased stoichiometry and quality are present at a higher Ts; and when annealed. The annealing of the films grown at Ts of 205 °C results in a much higher gain of the crystal quality compared to the gain when annealing the films grown at Ts of 320 °C, although the quality remain higher when deposited at Ts of 320 °C. Simultaneously with the increase of the film quality, there is a sign of increased quality of the crystal ordering with indium in the octahedral sites. Such a crystal ordering favor the use of CSP deposited In2S3 films in the intermediate band solar cells.

Electronics, Electronique, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Nanomatériaux et nanostructures : fabrication et caractèrisation, Nanoscale materials and structures: fabrication and characterization, Nanotubes, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Catalyseurs: préparations et propriétés, Catalysts: preparations and properties, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Electronique moléculaire, nanoélectronique, Molecular electronics, nanoelectronics, Activité catalytique, Catalyst activity, Actividad catalítica, Aire superficielle, Surface area, Area superficial, Cinétique, Kinetics, Cinética, Colorant basique, Basic dye, Colorante básico, Colorant thiazinique, Thiazine dye, Colorante tiazínico, Courant impulsionnel, Pulse current, Corriente impulsional, Dégradation, Degradation, Degradación, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Endommagement, Damaging, Deterioración, Evaluation performance, Performance evaluation, Evaluación prestación, Fabrication microélectronique, Microelectronic fabrication, Fabricación microeléctrica, Matériau composite, Composite material, Material compuesto, Nanoparticule, Nanoparticle, Nanopartícula, Nanotechnologie, Nanotechnology, Nanotecnología, Nanotube, Nanotubo, Oxyde de titane, Titanium oxide, Titanio óxido, Photocatalyse, Photocatalysis, Fotocatálisis, Réseau (arrangement), Array, Red, Solution aqueuse, Aqueous solution, Solución acuosa, 8107D, 8245J, 8540H, TiO2, Ag-deposited TiO2 nanotube, Bamboo-type TiO2 nanotubes, Photocatalytic activity, and Pulse-current electrodeposition

Photocatalysis phenomena in TiO2 have been intensively investigated for its potential application in environmental remediation. The present work reports improved photocatalytic degradation of methylene blue dye in aqueous solution by using bamboo-type TiO2 nanotubes deposited with Ag nanoparticles via electrochemical deposition. The photocatalytic processes are performed on Ag-modified TiO2 bamboo-type nanotube arrays, Ag-modified smooth-walled nanotube arrays, and bare smooth-walled nanotube arrays. Both Ag-modified bamboo-type and smooth-walled nanotube arrays show improved photocatalytic degradation efficiencies (64.4% and 52.6%) compared to smooth-walled TiO2 nanotubes of the same length (44.4%), due to the enhanced electron-hole seperation and more surface area provided by bamboo ridges. The photocatalytic activity and kinetic behavior of Ag-modified bamboo-type nanotube arrays are also optmized by tuning pulse deposition time of Ag nanoparticles. Bamboo-type nanotubes deposited with Ag nanoparticles via pulse deposition time of 0.5 s/1.5 s shows the highest methylene blue degradation efficiency of 78.5%, which represents 21.9% and 76.8% enhancement of efficiency compared to those of bare bamboo-type and smooth-walled nanotubes, respectively, indicating that a proper amount of Ag nanoparticles on TiO2 can maximize the photocatalytic processes. In addition, overly long pulse deposition time will not further increase photocatalytic activity due to agglomeration of Ag paticles. For example, when the pulse deposition time is increased to 2 s/6 s, Ag-modified bamboo-type nanotube array exhibits a lower photocatalytic degradation efficiency of 62.9%.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Préparation, cinétique, thermodynamique, mécanisme et catalyseurs, Preparation, kinetics, thermodynamics, mechanism and catalysts, Polymérisation, Polymerization, Agrégation moléculaire, Molecular aggregation, Agregación molecular, Cobalt II Complexe, Cobalt II Complexes, Cobalto II Complejo, Copolymère biséquencé, Diblock copolymer, Copolímero bisecuencia, Copolymère triséquencé, Triblock copolymer, Copolímero trisecuencia, Effet température, Temperature effect, Efecto temperatura, Etude expérimentale, Experimental study, Estudio experimental, Imidazolium(vinyl) sel copolymère, Imidazolium(vinyl) salt copolymer, Imidazolio(vinil) sal copolímero, Liquide ionique, Ionic liquid, Líquido iónico, Morphologie, Morphology, Morfología, Polymère amphiphile, Amphiphilic polymer, Polímero amfifilo, Polymère monodispersé, Monodispersed polymer, Polímero monodispersado, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Polymérisation solution, Solution polymerization, Polimerización solución, Préparation, Preparation, Preparación, Solution aqueuse, Aqueous solution, Solución acuosa, Solution organique, Organic solution, Solución orgánica, Structure domaine, Domain structure, Estructura dominio, Vinylique acétate copolymère, Vinyl acetate copolymer, Vinílico acetato copolímero, Imidazolium(3-butyl-1-vinyl) sel copolymère, Liquide ionique copolymère, Polymérisation contrôlée cobalt, CMRP, block copolymer, mesostructure, poly(ionic liquid), and self-assembly

A poly(ionic liquid)-based block copolymer (PIL BCP), namely, poly(vinyl acetate)-b-poly(N-vinyl-3-butylimidazolium bromide), PVAc-b-PVBuImBr, is synthesized by sequential cobalt-mediated radical polymerization (CMRP). A PVAc precursor is first prepared at 30 °C in bulk by CMRP of VAc, using bis(acetylacetonato)cobalt(II), Co(acac)2, and a radical source (V-70). Growth of PVBuImBr from PVAc-Co(acac)2 is accomplished by CMRP in DMF/MeOH (2:1, v/v). This PIL BCP self-assembles in the sub-micron size range into aggregated core-shell micelles in THF, whereas polymeric vesicles are observed in water, as evidenced by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Thin-solid sample cut from raw materials analyzed by TEM shows an ordered lamellar organization by temperature-dependent synchrotron small-angle X-ray scattering (SAXS). Anion exchange can be accomplished to achieve the corresponding PIL BCP with bis(trifluorosulfonyl)imide (Tf2N-) anions, which also gives rise to an ordered lamellar phase in bulk samples. A complete suppression of SAXS second-order reflection suggests that this compound has a symmetric volume fraction (f ≈ 0.5). SAXS characterization of both di- and triblock PIL BCP analogues previously reported also shows a lamellar phase of very similar behavior, with only an increase of the period by about 8% at 60 °C.

Electronics, Electronique, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Autres méthodes de préparation et de traitement des matériaux, Materials synthesis; materials processing, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Catalyseurs: préparations et propriétés, Catalysts: preparations and properties, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Rupture, Fractures, Composé III-VI, III-VI compound, Compuesto III-VI, Activité catalytique, Catalyst activity, Actividad catalítica, Agent surface, Surfactant, Agente superficie, Oberflaechenaktiver Stoff, Aire surface spécifique, Specific surface area, Anatase, Anatasa, Calcination, Calcining, Calcinación, Kalzinieren, Catalyseur, Catalyst, Catalizador, Katalysator, Colorant azoïque, Azo dye, Colorante azoico, Colorant bisazoïque, Bisazo dye, Colorante bisazoico, Constante vitesse réaction, Reaction rate constants, Cristallite, Crystallites, Cristalita, Kristallit, Dégradation chimique, Chemical degradation, Degradación química, Endommagement, Damaging, Deterioración, Matériau poreux, Porous material, Material poroso, Poroeser Werkstoff, Mésoporosité, Mesoporosity, Mesoporosidad, Oxyde d'indium, Indium oxide, Indio óxido, Indiumoxid, Oxyde de titane, Titanium oxide, Titanio óxido, Titanoxid, Photocatalyse, Photocatalysis, Fotocatálisis, Poudre, Powder, Polvo, Pulver, Procédé sol gel, Sol gel process, Procedimiento sol gel, Rutile, Rutilo, Solution aqueuse, Aqueous solution, Solución acuosa, Waesserige Loesung, Transformation phase, Phase transformation, Transformación fase, Phasenumwandlung, 6470N, 8105R, 8116H, 8245J, In2O3, TiO2, and Photocatalytic degradation

This work focuses on the improvement of the photocatalytic activity of mesoporous-assembled In2O3-TiO2 mixed oxide photocatalysts for Congo Red (CR) azo dye degradation by varying the In2O3-to-TiO2 molar ratio and calcination temperature. All of photocatalysts are synthesized by a sol-gel process with the aid of a structure-directing surfactant. The results show that the incorporation of In2O3 to the mesoporous-assembled TiO2 can increase the specific surface area and total pore volume, inhibit the anatase-to-rutile phase transformation, and decrease the crystallite size of the resulting In2O3-TiO2 mixed oxide photocatalysts. The mesoporous-assembled 0.05In2O3-0.95TiO2 mixed oxide photocatalyst with an In2O3-to-TiO2 molar ratio of 0.05:0.95 (5 mol% In2O3 incorporation) and calcined at 500 °C exhibits the highest CR dye degradation activity (with reaction rate constant of 0.86 h-1 being considerably higher than that of the commercial P-25 TiO2 powder.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Cinétique, Kinetics, Cinética, Congélation, Freezing, Congelación, Diffusion RX centrale, Small angle X ray scattering, Difusión rayo X central, Effet solvant, Solvent effect, Efecto solvente, Enchevêtrement moléculaire, Molecular entanglement, Encabestradura molecular, Etat actuel, State of the art, Estado actual, Gel physique, Physical gel, Gel físico, Gélification, Gelation, Gelificación, Hydrogel, Hidrogel, Liaison hydrogène, Hydrogen bond, Enlace hidrógeno, Macroporosité, Macroporosity, Macroporosidad, Solution aqueuse, Aqueous solution, Solución acuosa, Vinylique alcool polymère, Polyvinylalcohol, Vinílico alcohol polímero, Cristallisation confinée, Confined polymer crystallization, Cryotropic gelation, Ostwald stage-rule, Poly(vinyl alcohol) hydrogels, and Time-resolving small angle neutron scattering

Aqueous poly(vinyl alcohol) (PVA) solutions subjected to cryogenic treatment form strong physical gels. The cryogenic treatment basically consists of freezing an initially homogeneous polymer solution at low temperatures, storing in the frozen state for a definite time, and defrosting. These gels are of great interest for biotechnology, medicine, the food industry, and many other applications. The outstanding properties of these systems depend on a complex macroporous architecture, whereby PVA chains and water molecules are organized over different hierarchical length scales. The structure and the principal processes subtending the formation of these systems are discussed in the framework of our current understanding of polymer gels. These processes involve formation of ice crystals, PVA crystallization, liquid-liquid phase separation, hydrogen bonding, and entanglements. Small angle neutron scattering is used to follow the cryotropic gelation of PVA/water solutions and detailed information is extracted concerning the gelation mechanism and kinetic parameters related to the formation of these complex systems.

Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Géochimie, Geochemistry, Géologie de l'ingénieur et de l'environnement. Géothermie, Engineering and environment geology. Geothermics, Pollution, géologie de l'environnement, Pollution, environment geology, Roche ignée, igneous rocks, Roca ignea, Roche plutonique, plutonic rocks, Roca granuda, Aquifère, aquifers, Atmosphère, atmosphere, Atmósfera, Carotte, drill cores, Testigo, Concentration, concentration, Concentración, Dimension grain, grain size, Dimensión grano, Diorite, diorites, Diorita, Eau souterraine, ground water, Agua subterránea, Electrolyte, electrolytes, Electrólito, Etude expérimentale, experimental studies, In situ, in situ, Isotherme, isotherms, Isothermo, Matériau, materials, Méthode laser, laser methods, Laser, Roche cristalline, crystalline rocks, Roca cristalina, Réduction, reduction, Rétention, retention, Solution aqueuse, aqueous solutions, Solución acuosa, Sorption, sorption, Sorción, Spectrométrie fluorescence, fluorescence spectroscopy, Espectrometría fluorescencia, Température, temperature, Temperatura, Transformation Fourier, Fourier transformation, Uranium, uranium, and Uranio

Pristine diorite drill cores, obtained from the Äspö Hard Rock Laboratory (HRL, Sweden), were used to study the retention properties of fresh, anoxic crystalline rock material towards the redox-sensitive uranium. Batch sorption experiments and spectroscopic methods were applied for this study. The impact of various parameters, such as solid-to-liquid ratio (2-200 g/L), grain size (0.063-0.2 mm, 0.5-1 mm, 1-2 mm), temperature (room temperature and 10 °C), contact time (5-108 days), initial U(VI) concentration (3 × 10-9 to 6 × 10-5 M), and background electrolyte (synthetic Äspö groundwater and 0.1 M NaClO4) on the U(VI) sorption onto anoxic diorite was studied under anoxic conditions (N2). Comparatively, U(VI) sorption onto oxidized diorite material was studied under ambient atmosphere (pCO2 = 10-3.5 atm). Conventional distribution coefficients, Kd, and surface area normalized distribution coefficients, Ka, were determined. The Kd value for the U(VI) sorption onto anoxic diorite in synthetic Äspö groundwater under anoxic conditions by investigating the sorption isotherm amounts to 3.8 ± 0.6 L/kg which corresponds to Ka = 0.0030 ± 0.0005 cm (grain size 1-2 mm). This indicates a weak U sorption onto diorite which can be attributed to the occurrence of the neutral complex Ca2UO2(CO3)3(aq) in solution. This complex was verified as predominating U species in synthetic Äspö groundwater by time-resolved laser-induced fluorescence spectroscopy (TRLFS). Compared to U sorption at room temperature under anoxic conditions, U sorption is further reduced at decreased temperature (10 °C) and under ambient atmosphere. The U species in aqueous solution as well as sorbed on diorite were studied by in situ time-resolved attenuated total reflection Fourier-transform infrared (ATR FT-IR) spectroscopy. A predominant sorbing species containing a UO2(CO3)43- moiety was identified. The extent of U sorption onto diorite was found to depend more on the low sorption affinity of the Ca2UO2(CO3)3(aq) complex than on reduction processes of uranium.