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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), Photochimie, Photochemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Gels colloïdaux. Sols colloïdaux, Colloidal gels. Colloidal sols, Matériaux poreux, Porous materials, Alcanol, Alkanol, Alcool, Alcohol, Acidité, Acidity, Acidez, Adsorption, Adsorción, Aire superficielle, Surface area, Area superficial, Analyse thermique différentielle, Differential thermal analysis, Análisis térmico diferencial, Conception, Design, Diseño, Copolymère triséquencé, Triblock copolymer, Copolímero trisecuencia, Couche mince, Thin film, Capa fina, Diffraction RX, X ray diffraction, Difracción RX, Ethanol, Etanol, Film, Película, Frittage, Sintering, Sinterización, Hexane, Hexano, Matériau poreux, Porous material, Material poroso, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Mésoporosité, Mesoporosity, Mesoporosidad, Métal transition composé, Transition element compounds, Photocatalyse, Photocatalysis, Fotocatálisis, Poloxamère, Poloxamer, Poloxámero, Procédé sol gel, Sol gel process, Procedimiento sol gel, Propriété optique, Optical properties, Propiedad óptica, Réaction catalytique, Catalytic reaction, Reacción catalítica, Réaction photochimique, Photochemical reaction, Reacción fotoquímica, Spectrométrie UV visible, Ultraviolet visible spectrometry, Espectrometría UV visible, Structure, Estructura, Titane oxyde, Titanium oxide, Titanio óxido, Traitement surface, Surface treatment, Tratamiento superficie, Zircone, Zirconia, Zircona, Zirconium oxyde, Zirconium oxide, Zirconio óxido, Agent structurant, and Template

Optically transparent, crack-free mesoporous titania and zirconia-doped titania thin films were fabricated by the sol-gel technique using the non-ionic amphiphilic triblock copolymer Pluronic P123 as the template. The structure and optical properties of these films were characterized using TEM, low-angle XRD, DTA/TG measurements, UV-vis spectroscopy and hexane adsorption investigations. It was found that addition of ZrO2 into the TiO2 matrix retarded sintering of the films, thereby increasing the specific surface area after treatment up to 500°C. The catalytic activity of the mesoporous TiO2 and TiO2/(5-30%) ZrO2 films in ethanol photo-oxidation increased with increasing specific surface area and surface acidity of the samples.

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 de surface, Surface physical chemistry, Métal transition composé, Transition element compounds, Adsorbant, Adsorbent, Adsorbente, Angle contact, Contact angle, Angulo contacto, Eau, Water, Agua, Hydrophobicité, Hydrophobicity, Hidrofobicidad, Microcalorimétrie, Microcalorimetry, Microcalorimetría, Oxyde, Oxides, Óxido, Oxygène, Oxygen, Oxígeno, Polymère, Polymer, Polímero, Propriété surface, Surface properties, Propiedad superficie, Silice, Silica, Sílice, Siloxane(diméthyl) polymère, Dimethylsiloxane polymer, Siloxano(dimetil) polímero, Titane oxyde, Titanium oxide, and Titanio óxido

Microcalorimetry and measurements of the contact angle of water were performed to investigate the hydrophilic/hydrophobic properties of silica surfaces modified with metal oxides and polydimethylsiloxane (PDMS) at 20-500°C. Fumed silicas whose surfaces contained grafted oxygen compounds of metals were used as adsorbents, with VOCl3, CrO2Cl2, TiCl4, SnCl4, AlCl3 and Zn(acac)2 vapours being applied as modifiers. It was found that the hydrophobic coating of silicas modified with metal oxides and PDMS (8-40 wt%) was stable over the temperature range 100-350°C. With a titania coating, the hydrophobic properties were retained at temperatures up to 500°C for an adsorbed polymer content of 20-40 wt%.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Métal transition Composé, Transition metal Compounds, Metal transición Compuesto, Aire superficielle, Surface area, Area superficial, Charbon actif, Activated carbon, Carbón activado, Chrome composé, Chromium compound, Cromo compuesto, Complexation, Complexación, Cuivre composé, Copper compound, Cobre compuesto, Etude expérimentale, Experimental study, Estudio experimental, Extraction solvant, Solvent extraction, Extracción solvente, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Lessivage, Leaching, Lavado, Processus supercritique, Supercritical process, Proceso supercrítico, Procédé extraction, Extraction process, Procedimiento extracción, Solution acide, Acidic solution, Solución ácida, Zinc composé, Zinc compound, and Zinc compuesto

The usefulness of extraction methods such as leaching, extraction with complex-forming organic solvents and supercritical extraction in recovering metals and carbon carriers from dangerous wastes such as carbon impregnates and catalysts is discussed.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Propriété surface, Surface properties, Propiedad superficie, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Agent surface anionique, Anionic surfactant, Agente superficie aniónico, Aluminium Oxyde, Aluminium Oxides, Aluminio Óxido, Epaisseur couche, Layer thickness, Espesor capa, Ethylène oxyde polymère, Ethylene oxide polymer, Etileno óxido polímero, Etude expérimentale, Experimental study, Estudio experimental, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Sodium composé, Sodium compound, Sodio compuesto, Solution aqueuse, Aqueous solution, Solución acuosa, Structure adsorption, Adsorption structure, Estructura adsorción, Sulfate(lauryl), Lauryl sulfate, Lauril sulfato, Tension superficielle, Surface tension, Tensión superficial, Vinylique alcool polymère, Polyvinylalcohol, and Vinílico alcohol polímero

The influence of sodium dodecyl sulphate (SDS) on the adsorption properties of non-ionic polymers, i.e. polyethylene glycol (PEG) and polyvinyl alcohol (PVA), at the Al2O3/solution interface was studied. Measurements for various molecular weights and for various amounts of functional groups on the polymer macromolecules were undertaken and the results obtained discussed in the light of these variations. Studies of the mutual interactions of the polymer-surfactant system in aqueous solution were helpful in explaining the equilibria involved in the Al2O3/polymer solution system in the presence of SDS. The thickness of the adsorption layer was determined by viscometric methods and the influence of the degree of hydrolysis of PVA on the structure of the adsorption layer demonstrated.

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 de surface, Surface physical chemistry, Interface gaz-liquide et liquide-liquide, Gas-liquid interface and liquid-liquid interface, Interface solide-liquide, Solid-liquid interface, Métal transition Composé, Transition metal Compounds, Metal transición Compuesto, Adsorption, Adsorción, Agent surface anionique, Anionic surfactant, Agente superficie aniónico, Aluminium hydroxyde, Aluminium hydroxide, Aluminio hidróxido, Etude expérimentale, Experimental study, Estudio experimental, Fer hydroxyde, Iron hydroxide, Hierro hidróxido, Interface gaz liquide, Gas liquid interface, Interfase gas líquido, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Isotherme Freundlich, Freundlich isotherm, Isoterma Freundlich, Isotherme Langmuir, Langmuir isotherm, Isoterma Langmuir, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Sodium composé, Sodium compound, Sodio compuesto, Solution aqueuse, Aqueous solution, Solución acuosa, Sulfate(lauryl), Lauryl sulfate, Lauril sulfato, Benzènesulfonate(lauryl), and Sulphanol NP-3

The adsorption of sodium dodecyl sulphate and sulphanol NP-3 by iron(III) and aluminium hydroxides was studied. The applicability of the Langmuir, Freundlich and Hill-de Boer adsorption equations for the description of the adsorption isotherms obtained experimentally was verified. Values of various parameters characterising the adsorption of the anionic surfactants investigated by iron(III) and aluminium hydroxides have been calculated. These allowed assumptions to be made about the adsorption mechanism. The possibility of using air as an adsorbent for anionic surfactants was studied.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Métal transition Composé, Transition metal Compounds, Metal transición Compuesto, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Amine, Amina, Composé benzénique, Benzenic compound, Compuesto bencénico, Etude expérimentale, Experimental study, Estudio experimental, Hétérocycle azote, Nitrogen heterocycle, Heterociclo nitrógeno, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Molybdène carbonate, Molybdenum carbonate, Molibdeno carbonato, Méthode dynamique moléculaire, Molecular dynamics method, Método dinámico molecular, Potentiel ionisation, Ionization potential, Potencial de ionización, Propriété surface, Surface properties, Propiedad superficie, Solution aqueuse, Aqueous solution, Solución acuosa, Transfert électron, Electron transfer, and Transferencia electrón

The energies of unoccupied and occupied orbitals have been used as correlation parameters between the electronic and adsorptive properties of organic molecules. A model describing the chemisorption of organic compounds on MnCO3 was proposed. This involves three types of interaction: 1-, 2- and 3-electron donor-acceptor interaction between adsorbent and adsorbate frontier orbitals.

General chemistry, physical chemistry, Chimie générale, chimie physique, 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, Aire superficielle, Surface area, Area superficial, Benzène(divinyl) copolymère, Benzene(divinyl) copolymer, Benceno(divinil) copolímero, Chromatographie phase gazeuse, Gas chromatography, Cromatografía fase gaseosa, Copolymérisation suspension, Suspension copolymerization, Copolimerización suspensión, Etude expérimentale, Experimental study, Estudio experimental, Indice rétention, Retention index, Indice retención, Matériau poreux, Porous material, Material poroso, Monomère, Monomer, Monómero, Méthacrylate copolymère, Methacrylate copolymer, Metacrilato copolímero, Phase stationnaire, Stationary phase, Fase estacionaria, Relation structure propriété, Property structure relationship, Relación estructura propiedad, Styrène copolymère, Styrene copolymer, Estireno copolímero, Sulfone copolymère, Sulfone copolymer, Sulfona copolímero, Sélectivité, Selectivity, and Selectividad

Four types of porous methacrylate polymers were synthesized as stationary phases for gas chromatography. The influence of the chemical structure of the monomers used in the synthesis on the selectivities of the resulting polymers was studied. Two procedures were applied to determine the selectivities of the copolymers: the selectivity triangle and the general selectivity. Porapak Q, the least polar commercially available porous polymer, was used as a reference phase.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Propriété surface, Surface properties, Propiedad superficie, Activité superficielle, Surface activity, Actividad superficial, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Alkylamine, Alquilamina, Alliage amorphe, Amorphous alloy, Aleación amorfa, Alliage n éléments, Multi-element alloys, Bore Alliage, Boron Alloys, Boro Aleación, Capacité adsorption, Adsorption capacity, Capacidad adsorción, Etude expérimentale, Experimental study, Estudio experimental, Fer alliage, Iron alloy, Hierro aleación, Hétérocycle azote, Nitrogen heterocycle, Heterociclo nitrógeno, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Molybdène alliage, Molybdenum alloy, Molibdeno aleación, Nickel alliage, Nickel alloy, Níquel aleación, Pipéridine, Silicium alliage, Silicon alloy, Silicio aleación, Sodium chlorure, Sodium chloride, Sodio cloruro, Solution aqueuse, Aqueous solution, Solución acuosa, Solution électrolyte, Electrolyte solution, Solución electrólito, Traitement thermique, Heat treatment, Tratamiento térmico, B Fe Mo Ni Si, Diéthylamine, Fe(78,5)Ni(1,0)Mo(0,5)Si(6,0)B(14,0), and Morpholine

The change in the adsorption abilities of surfaces of amorphous metallic alloys (AMA) after thermal treatment (at 77-773 K) was estimated by various physicochemical methods. It was shown that the extent of piperidine adsorption on an AMA surface subjected to thermal treatment correlated with the results of X-ray structural analysis.

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, Réactions catalytiques, Catalytic reactions, Métal transition, Transition metal, Metal transición, Aire superficielle, Surface area, Area superficial, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Charbon, Coal, Carbón, Densité, Density, Densidad, Désulfuration, Desulfurization, Desulfuración, Effet concentration, Concentration effect, Efecto concentración, Effet structure, Structure effect, Efecto estructura, Etude expérimentale, Experimental study, Estudio experimental, Gaz combustion, Combustion gas, Gas combustión, Molybdène, Molybdenum, Molibdeno, Préparation, Preparation, Preparación, Réaction catalytique, Catalytic reaction, Reacción catalítica, Soufre dioxyde, Sulfur dioxide, Dióxido sulfúrico, Vanadium, and Vanadio

The catalytic removal of SO2 from combustion gases has been studied on the grain plane of a hard coal, being competitive with classical desulphurization processes. The method proposed for the removal of SO2 from combustion gases described in this paper is quite different from wet classical desulphurization methods. Studies of the influence of molybdenum concentration on the catalytic activity of a number of DESONOX catalysts are reported. The influence of the total surface area and other physicochemical properties of the catalyst on its behaviour have been studied.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Métal transition Composé, Transition metal Compounds, Metal transición Compuesto, Acrylamide polymère, Acrylamide polymer, Acrilamida polímero, Acrylique acide polymère, Acrylic acid polymer, Acrílico ácido polímero, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Charge superficielle, Surface charge, Carga superficial, Energie adsorption, Adsorption energy, Energía adsorción, Epaisseur couche, Layer thickness, Espesor capa, Etude expérimentale, Experimental study, Estudio experimental, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Manganèse oxyde, Manganese oxides, Manganeso óxido, Masse moléculaire, Molecular mass, Masa molecular, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Potentiel électrocinétique, Electrokinetic potential, Potencial electrocinético, Structure adsorption, Adsorption structure, Estructura adsorción, and pH

The influence of the molecular weight of polyelectrolytes on their adsorption and on the structure of the adsorbed layers at the manganese oxide(IV)-polymer solution interface was determined. Polyacrylic acid (PAA) and polyacrylamide (PAM) were applied as ionic polymers. An explanation was proposed for the observed changes in surface charge and zeta potential of the solid in the presence of these polymers. The thickness of the adsorption layer of PAA and PAM was determined and the free energies of adsorption of these polymers on the MnO2 surface were calculated from the zeta potential measurements.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Calcium carbonate, Calcio carbonato, Chimisorption, Chemisorption, Adsorción química, Composé aromatique, Aromatic compound, Compuesto aromático, Etude expérimentale, Experimental study, Estudio experimental, Hétérocycle azote, Nitrogen heterocycle, Heterociclo nitrógeno, Hétérocycle oxygène, Oxygen heterocycle, Heterociclo oxígeno, Interaction orbitale, Orbital interaction, Interacción orbital, Interaction électronique, Electron interaction, Interacción electrónica, Isotherme Langmuir, Langmuir isotherm, Isoterma Langmuir, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Modélisation, Modeling, Modelización, Solution aqueuse, Aqueous solution, and Solución acuosa

The energies of unoccupied and occupied orbitals were used as the correlation parameters between the electronic and adsorptive properties of organic molecules. A model describing the chemisorption of organic compounds on CaCO3 involving two types of interaction, i.e. two-electron, donor-acceptor interaction HOMO(adsorbent) → LUMO(adsorbate) and four-electron, three-orbital interaction HOMO(adsorbent) → {LUMO(adsorbate) + HOMO(adsorbate)}, was proposed. It was concluded that strengthening of the bond involved in chemisorption occurred if the energies of the occupied orbitals associated with the adsorbate and adsorbent were concurrent.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Alcane, Alkane, Alcano, Alcanol, Alkanol, Alcool, Alcohol, Analyse thermique, Thermal analysis, Análisis térmico, Azote, Nitrogen, Nitrógeno, Benzène, Benzene, Benceno, Butanol, Charbon actif, Activated carbon, Carbón activado, Eau, Water, Agua, Etude comparative, Comparative study, Estudio comparativo, Film liquide, Liquid film, Capa líquida, Hydrocarbure, Hydrocarbon, Hidrocarburo, Hydrogène Peroxyde, Hydrogen Peroxides, Hidrógeno Peróxido, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Isotherme désorption, Desorption isotherm, Isotermo desorción, Matériau modifié, Modified material, Material modificado, Matériau poreux, Porous material, Material poroso, Octane, Octano, Porosité, Porosity, Porosidad, Sorption, Sorción, Thermogravimétrie, Thermogravimetry, and Termogravimetría

Thermal analysis was used to investigate the adsorbed water layers and surface properties of various pure and modified commercial activated carbons. In addition, the thermodesorption of n-butanol, n-octane and benzene from samples saturated in a vacuum desiccator was studied under quasi-isothermal conditions. The mass loss Q-TG and differential mass loss Q-DTG curves obtained consisted of steps and inflections which were associated with the mechanism of wetting, adsorption and porosity properties of the studied surfaces. Adsorption/desorption isotherms of nitrogen on the activated carbon samples were measured using a sorptiomatic method. The specific surface areas, pore sizes, pore volumes and pore-size distribution functions have been calculated for the various samples. A correlation between the porosity parameters obtained from thermogravimetric and sorptiometric methods is presented.

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, Electrochimie, Electrochemistry, Cinétique et mécanisme des réactions, Kinetics and mechanism of reactions, DMF, N,N-Dimethylformamide, Dimetilformamida, Effet milieu, Medium effect, Efecto medio, Electrode, Electrodes, Electrodo, Ethanol, Etanol, Etude expérimentale, Experimental study, Estudio experimental, Mercure, Mercury, Mercurio, Méthanol, Methanol, Metanol, Méthyle sulfoxyde, Methyl sulfoxide, Sulfóxido de dimetilo, Réaction électrochimique, Electrochemical reaction, Reacción electroquímica, Réduction chimique, Chemical reduction, Reducción química, Sodium Perchlorate, Sodium Perchlorates, Sodio Perclorato, Solution aqueuse, Aqueous solution, Solución acuosa, Solvant mixte, Mixed solvent, Disolvente mixto, Thiourée, Thiourea, Tiourea, and Zinc II

The accelerating influence of thiourea on the ZnII/Zn(Hg) reduction process was investigated in the following mixed solutions: water-methanol (MeOH); water-ethanol (EtOH); water-dimethyl sulphoxide (DMSO); water-dimethylformamide (DMF). It was suggested that the dominant role in acceleration of the electrode process is played by the composition of the activated complex, which is presumably composed of solvent molecules and thiourea molecules adsorbed on to the electrode. A mechanism was proposed for the process occurring.

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 de surface, Surface physical chemistry, Matériaux adsorbants, Adsorbents, Adsorbant minéral, Inorganic adsorbent, Adsorbente inorgánico, Air, Aire, Alcane, Alkane, Alcano, Argon, Argón, Benzène, Benzene, Benceno, Carbone dioxyde, Carbon dioxide, Carbono dióxido, Dimension pore, Pore size, Dimensión poro, Dolomite, Dolomita, Décomposition, Decomposition, Descomposición, Effet température, Temperature effect, Efecto temperatura, Energie adsorption, Adsorption energy, Energía adsorción, Hydrocarbure, Hydrocarbon, Hidrocarburo, Matériau modifié, Modified material, Material modificado, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Octane, Octano, Propriété physicochimique, Physicochemical properties, and Propiedad fisicoquímica

The physicochemical properties of 'dolomitic' sorbents formed through the partial decomposition of dolomite have been discussed in two papers published previously dealing with the influence of temperature and the time of heating. When carried out at 800°C, the newly formed solid consisted of sponge-like calcite and finely powdered magnesium oxide which was resistant mechanically and exhibited considerably greater porosity than the raw material. Long-term heating led to a decrease in the porosity and to the partial elimination of pores. The corresponding 'dolomitic' sorbents prepared in an inert atmosphere showed even greater porosity and a different internal structure when compared to those formed in the presence of carbon dioxide. However, no changes were observed as far as the chemical composition was concerned.

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, Catalyseurs: préparations et propriétés, Catalysts: preparations and properties, Lanthanide, Lantánido, Métal alcalinoterreux, Alkaline earth metal, Metal alcalino-térreo, Métal transition, Transition metal, Metal transición, Aire superficielle, Surface area, Area superficial, Alcane, Alkane, Alcano, Baryum, Barium, Bario, Butane, Butano, Carbone dioxyde, Carbon dioxide, Carbono dióxido, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Catalyseur modifié, Modified catalyst, Catalizador modificado, Catalyseur sur support, Supported catalyst, Catalizador sobre soporte, Cérium, Cerium, Cerio, Eau, Water, Agua, Effet température, Temperature effect, Efecto temperatura, Hydrocarbure, Hydrocarbon, Hidrocarburo, Molybdène, Molybdenum, Molibdeno, Nickel, Niquel, Oxydation, Oxidation, Oxidación, Potassium, Potasio, Promoteur, Promoter, Promotor, Reformage catalytique, Catalytic reforming, Reformación catalítica, Reformage vapeur, Steam reforming, Reformación vapor, Température programmée, Programmed temperature, Temperatura programada, Tungstène, Tungsten, and Wolframio

Studies of the reforming of n-butane by steam and carbon dioxide have been undertaken employing commercial catalysts such as Ni/α-Al2O3 modified by small additions of promoters such as K, Ba, Ce, W and Mo compounds. It was found that promoters improved the resistance of the catalyst towards coking, with this effect being smaller where CO2 was employed in the reforming reaction than when steam was used. The dynamics of the growth of the carbon deposit on the catalyst surface depended on the promoters employed as well as on the operating conditions; however, in the CO2 reforming of n-butane, such coking was more pronounced than in steam reforming. Use of the TPO method with oxygen or CO2 did not reveal considerable differences between the coke deposits formed during the reforming of n-butane with CO2 or H2O on the catalysts examined.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Agent surface anionique, Anionic surfactant, Agente superficie aniónico, Carbonate, Carbonates, Carbonato, Effet concentration, Concentration effect, Efecto concentración, Ethylène oxyde polymère, Ethylene oxide polymer, Etileno óxido polímero, Etude expérimentale, Experimental study, Estudio experimental, Interaction intermoléculaire, Intermolecular interaction, Interacción intermolecular, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Sodium composé, Sodium compound, Sodio compuesto, Sulfate(lauryl), Lauryl sulfate, Lauril sulfato, Suspension particule, Particle suspension, Suspensión partícula, Système binaire, Binary system, and Sistema binario

Competitive adsorption between anionic surfactant (SDS) and neutral poly(ethylene oxide) polymers (PEO) on carbonate mine tailings was investigated, with experiments being performed to check the order of reagent addition. The PEO adsorption plateaux were strongly affected by the presence of pre-adsorbed surfactant molecules, while surfactant adsorption increased in the presence of pre-adsorbed polymer. Polymer-surfactant interaction at the solid-liquid interface depended on the order of reagent addition which significantly affected the floc diameter. Increasing floc diameter was attributed to the formation of a polymer-surfactant complex on the solid surface.

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, Catalyseurs: préparations et propriétés, Catalysts: preparations and properties, Métal transition, Transition metal, Metal transición, Alcane, Alkane, Alcano, Alumine, Alumina, Alúmina, Butane, Butano, Carbone, Carbon, Carbono, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Catalyseur modifié, Modified catalyst, Catalizador modificado, Catalyseur sur support, Supported catalyst, Catalizador sobre soporte, Coke, Coque, Hydrocarbure, Hydrocarbon, Hidrocarburo, Magnésium Oxyde, Magnesium Oxides, Magnesio Óxido, Molybdène, Molybdenum, Molibdeno, Méthane, Methane, Metano, Méthode mesure, Measurement method, Método medida, Nickel, Niquel, Potassium, Potasio, Promoteur, Promoter, Promotor, Reformage catalytique, Catalytic reforming, Reformación catalítica, Reformage vapeur, Steam reforming, Reformación vapor, Réaction catalytique, Catalytic reaction, and Reacción catalítica

Nickel catalysts are commonly used in many industrial processes including the hydrogenation, hydrotreatment, hydrogenolysis, methanation and steam reforming of hydrocarbons. One of the important problems associated with these processes is the coking of such catalysts and in the present paper a new technique for measuring the coking rate in the steam reforming of hydrocarbons is presented. The methodology employed eliminates objections raised concerning gravimetric methods which are most frequently employed in the study of the rate of coking of catalysts. Qualitative agreement between the results obtained using both methods was demonstrated for catalysts differing both in composition and texture. The new method allows a better characterization of the resistance towards coking of nickel on various supports and in the presence of various promoters.

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, Catalyseurs: préparations et propriétés, Catalysts: preparations and properties, Physicochimie de surface, Surface physical chemistry, Interface solide-gaz, Solid-gas interface, Activation, Activación, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Composé benzénique, Benzenic compound, Compuesto bencénico, Craquage catalytique fluide, Fluid catalytic cracking, Craqueo catalítico fluido, Cumène, Cumene, Cumeno, Etude expérimentale, Experimental study, Estudio experimental, Hydrocarbure, Hydrocarbon, Hidrocarburo, Kaolin, Caolín, Matériau poreux, Porous material, Material poroso, Préparation, Preparation, Preparación, Relation mise en œuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Réaction catalytique, Catalytic reaction, Reacción catalítica, Structure pores, Pore structure, Estructura poros, Tamis moléculaire, Molecular sieve, Tamiz molecular, Zéolite, Zeolite, and Zeolita

A series of samples of zeolite-containing microspheres (ZCMS) and fluid catalytic cracking (FCC) catalysts based on Prosyana (Ukraine) kaolin were synthesized in situ. Their adsorption and chemisorption characteristics were recorded using a nitrogen low-temperature adsorption/desorption method and temperature programmed desorption (TPD) of ammonia, respectively. It was shown that changes in the synthesis conditions had a considerable impact on the micro- and meso-porosity of the samples. A low-temperature band dominated the ammonia TPD spectra of the ZCMS samples, reflecting the retention of ammonia by the sodium cations of the zeolite acting as weak Lewis acid sites. ZCMS was found to display an appreciable activity in cumene cracking at 723 K. It was shown that during the conversion of ZCMS to FCC catalysts through the decationization and ultra-stabilization of the zeolite phase, the latter is appreciably destroyed giving rise to a considerable increase in the mesoporosity of the samples without any change in the average diameters of such mesopores. It was concluded that the catalyst stability is characterized by pores of an intermediate (20-30 Å) diameter, thereby demonstrating the strength of the linkage between the zeolite and matrix phases. The zeolite phase content and adsorption characteristics of catalysts prepared on the basis of Prosyana kaolin meet the demands of modern FCC catalysts.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Propriété thermodynamique, Thermodynamic properties, Propiedad termodinámica, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Chaleur adsorption, Heat of adsorption, Calor adsorción, Désorption, Desorption, Desorción, Effet température, Temperature effect, Efecto temperatura, Etude expérimentale, Experimental study, Estudio experimental, Gel silice, Silica gel, Gel sílice, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Paramètre cinétique, Kinetic parameter, Parámetro cinético, Phosphate organique, Organic phosphate, Fosfato orgánico, Silice, Silica, Sílice, Silicium Oxyde, Silicon Oxides, Silicio Óxido, Solution aqueuse, Aqueous solution, Solución acuosa, Sulfurique acide, Sulfuric acid, Sulfúrico ácido, pH, and Phosphate(tributyl)

The adsorption behaviour of tributyl phosphate (TBP) on silica gel was studied. It was found that the adsorption isotherm shapes were complicated, being considered as S- and L-type isotherms according to the Giles classification. Adsorption itself was polymolecular and of a physical nature, the first adsorptive layer involving hydrogen bonding between the protons of surface silanol groups and the electron-donating oxygen atom of the adsorbate molecule. Subsequent adsorption layers were formed via van der Waals interaction. The free energy of adsorption of the system lay between -22.1 kJ/mol and -23.8 kJ/mol. The enthalpy change was negative and very small, i.e. -6,3 kJ/mol, while the entropy change was positive and in the range 53.9 J/(mol K) to 55.4 J/(mol K). The increase in entropy was explained in terms of the mobility of the TBP molecules in the adsorptive layer arising from their replacement on the silica gel surface by water molecules derived from the aqueous medium.

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 de surface, Surface physical chemistry, Interface solide-liquide, Solid-liquid interface, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Cinétique, Kinetics, Cinética, Lutte antipollution, Pollution control, Lucha anticontaminación, Plomb Ion, Lead Ions, Plomo Ión, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Tamis moléculaire, Molecular sieve, Tamiz molecular, Traitement eau, Water treatment, Tratamiento agua, Zéolite, Zeolite, Zeolita, and Clinoptilotite

The adsorption of lead(II) ions on the natural forms of Transcarpathian zeolite under static and dynamic conditions was investigated. Partial conversion of inactive calcium ions in the zeolite into relatively more mobile sodium or ammonium ions resulted in an increase in the adsorption of Pb2+ ions. Similarly, partial removal of aluminium oxide from the zeolite changed its physicochemical properties and led to the maximum adsorption of lead(II) ions.