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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%.

Inorganic chemistry, Chimie minérale, Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements thermiques, Heat treatment, Assemblage et découpage thermique: aspects métallurgiques, Joining, thermal cutting: metallurgical aspects, Soudage, Welding, Cinétique, Kinetics, Cinética, Kinetik, Croissance grain, Grain growth, Crecimiento grano, Kornwachstum, Dendrite, Dendrita, Dendrit, Elément alliage, Alloying element, Elemento aleación, Legierungselement, Grosseur grain, Grain size, Grosor grano, Korngroesse, Inconel 625, Microstructure, Microestructura, Mikrogefuege, Phase Laves, Laves phase, Fase Laves, Laves Phase, Précipité, Precipitate, Precipitado, Ausscheidungsprodukt, Soudage TIG, GTA welding, Soldeo TIG, WIG Schweissen, Structure basaltique, Columnar structure, Estructura columnar, Stengelkristallgefuege, Ségrégation, Segregation, Segregación, Seigerung, Traitement thermique, Heat treatment, Tratamiento térmico, Waermebehandlung, Coarsening, Inconel 625 deposited metal, Phase transformation, and Post-weld heat treatment

The effect of post-weld heat treatment (PWHT) temperatures on the microstructure of Inconel 625 deposited metal (DM) was examined using an optical microscope (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The transformation mechanism of the yʺ → δ phase and the grain growth kinetics of the y' phase during PWHT were revealed. The results indicate that the microstructure of as-welded DM is composed of columnar grains of different sizes, of which the average grain size is approximately 160 μm. Certain precipitates, such as the dispersed γʹ phase, blocky MC-type carbide and irregular shape Laves phase, precipitate in the microstructure of the as-welded DM. Compared with as-welded DM, the microstructure of DM after PWHT at 650 °C for 4 h shows minimal variation. With an increase in PWHT temperature, a large number of body-centered tetragonal y phases precipitate at interdendrite regions in the microstructure of DM after PWHT at 750 °C for 4 h. When the PWHT temperature increases to 850 °C, the metastable γʺ phase directly transforms into a stable δ phase in shear mode, which exhibits a similar chemical composition but a different crystal structure than the y phase. At 950 °C, the γʺ phase and the δ phase disappear, whereas certain M6C-type carbides precipitate at the grain boundaries. Alloying elements such as Nb, Mo, Si, Al and Fe in the microstructure of as-welded DM exhibit segregation behavior. Due to an increasing PWHT temperature, the segregation behavior constantly weakens with minimal evolution to the temperature of 750 °C. Above this temperature, partition coefficients tend toward 1, and composition heterogeneity disappears at 950 °C. During PWHT, the y' phase continuously coarsens with an increase in PWHT temperature. The dynamic analysis shows that the coarsening behavior of the y' phase corresponds with the formula: d3 ― d30 = A · e―Q/RT /T · t with an activation energy of 253 kJ/mol.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Atomic molecular physics, Physique atomique et moléculaire, Condensed state physics, Physique de l'état condensé, 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, Alcanol, Alkanol, Alcool, Alcohol, Aliment, Food, Alimento, Catalyseur, Catalyst, Catalizador, Cinétique, Kinetics, Cinética, Corrélation, Correlation, Correlación, Effet solvant, Solvent effect, Efecto solvente, Epoxydation, Epoxidation, Epoxidación, Etat transition, Transition state, Estado transitorio, Ethanol, Etanol, Isomère, Isomer, Isómero, Liaison hydrogène, Hydrogen bond, Enlace hidrógeno, Mécanisme, Mechanism, Mecanismo, Méthode fonctionnelle densité, Density functional method, Oxyde, Oxides, Óxido, Peroxyde d'hydrogène, Hydrogen peroxide, Peróxido de hydrogeno, Réactivité chimique, Chemical reactivity, Reactividad química, Solvant organique, Organic solvent, Solvente orgánico, Stabilisation, Stabilization, Estabilización, density functional calculations, epoxidation, hydrogen bonds, kinetics, and solvent effects

In our attempt to synthesize β-caryophyllene oxide in food-compatible conditions, we observed the uncatalyzed and highly selective epoxidation of β-caryophyllene, a strained bicyclic sesquiterpene, in ethanol with aqueous H2O2 under radical-suppressing conditions without the addition of a catalyst. The unusual reactivity of β-caryophyllene allowed us to use it as a probe for the mechanism of the solvent-assisted epoxidation in a wide range of organic solvents. A kinetic study was performed to investigate the epoxidation mechanism; an excellent correlation was found between the observed epoxidation rates in different solvents and the Abraham's hydrogen bond formation parameters of these solvents. By means of computational analysis, it was found that the main role of the solvent consists of the stabilization of the elongated O―O bond of H2O2 in the transition state through hydrogen-bond donation to the leaving OH moiety of H2O2. α-Humulene was found to possess similar reactivity as β-caryophyllene whereas isocaryophyllene—the unstrained isomer of β-caryophyllene—was unreactive.

Electronics, Electronique, Condensed state physics, Physique de l'état condensé, 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, Lactone copolymère, Lactone copolymer, Lactona copolímero, Propriété biologique, Biological properties, Propiedad biológica, Propriété optique, Optical properties, Propiedad óptica, Propriété électrique, Electrical properties, Propiedad eléctrica, Acide copolymère, Acid copolymer, Acido copolímero, Caprolactone copolymère, Caprolactone copolymer, Caprolactona copolímero, Cinétique, Kinetics, Cinética, Colorant organique, Organic dye, Colorante orgánico, Conductivité électrique, Electrical conductivity, Conductividad eléctrica, Copolymère greffé, Graft copolymer, Copolímero injertado, Copolymère triséquencé, Triblock copolymer, Copolímero trisecuencia, Cytotoxicité, Cytotoxicity, Citotoxicidad, Etude expérimentale, Experimental study, Estudio experimental, Fluorescence, Fluorescencia, Greffage, Grafting, Injerto, In vitro, Libération, Release, Liberación, Polymère amphiphile, Amphiphilic polymer, Polímero amfifilo, Polymère conducteur, Conducting polymers, Polymère vecteur, Control release polymer, Polímero vector, Polymérisation ouverture cycle, Ring opening polymerization, Polimerización abertura ciclo, Polymérisation oxydante, Oxidative polymerization, Polimerizacion oxidante, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Propriété électrochimique, Electrochemical properties, Propiedad electroquímica, Préparation, Preparation, Preparación, Réaction successive, Successive reaction, Reacción consecutiva, Stabilité thermique, Thermal stability, Estabilidad térmica, THF, Tetrahydrofurane, Furano(tetrahidro), Terpolymère, Terpolymer, Terpolímero, Tétrahydrofurane copolymère, Tetrahydrofuran copolymer, Tetrahidrofurano copolímero, Vecteur médicament, Drug carrier, Vector medicamento, pH, Aniline dérivé copolymère, Aniline derivative copolymer, Aniline(3-carboxy) copolymère, Characterization, Conductivity, Cyclic voltammetry, and Drug release system

The poly(tetrahydrofuran) (PTHF) grafted poly(caprolactone)-poly(anthranilicacid)-poly(caprolactone) (PCL-PAA-PCL) co-polymer system was synthesized by using a prepolymer under nitrogen atmosphere in the presence of a stannous octoate catalyst. The [M0/l0] was maintained at 100. The polymers at each stage was characterized by various analytical techniques like FTIR spectroscopy, NMR spectroscopy, UV-visible spectroscopy, fluorescence spectroscopy, cyclic voltammetry, DSC, TGA, conductivity, FESEM, solubility test, cytotoxicity and drug release study. The results obtained here in the present investigation are critically compared with the literature values.

Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Généralités, General, Champ électrique, Electric field, Campo eléctrico, Elektrisches Feld, Cinétique, Kinetics, Cinética, Kinetik, Décharge étincelle, Spark discharge, Descarga chispa, Frittage réactif, Reaction sintering, Sinterización reactivo, Microstructure, Microestructura, Mikrogefuege, Métallurgie poudre, Powder metallurgy, Metalurgia polvo, Pulvermetallurgie, Plasma, Synthèse, Synthesis, and Síntesis

The current study shows the dramatic effect of an electric field (EF) and use of nanosized cryomilled grains on accelerating sintering kinetics during spark plasma sintering of blended elemental powder compacts of Ti53Al47 targeted to produce γ-TiAl intermetallic compounds. The EF had the dominating effect since it reduced the activation barrier for diffusion through Al3Ti leading to faster growth of Al3Ti; the precursor to γ-TiAl. The Avrami exponent (n) determined for the micrograin compact lies between 1.0 and 1.5, which indicates that reaction sintering is controlled by bulk diffusion in these compacts, while for cryomilled compacts this is between 0.7 and 1.0 suggesting the important role of dislocations and grain boundaries on the transformation during reaction sintering. The activation energies were found to be in increasing order as: cryomilled compacts with EF (182 kJ/mol); micrograin compacts with EF (290 kJ/mol); cryomilled compacts without EF (331 kJ/mol); and micrograin compacts without EF (379 kJ/mol). The cryomilled microstructure also enhanced the sintering kinetics because of the availability of faster diffusing paths in Al and Ti including larger grain boundary area and dislocation density.

Inorganic chemistry, Chimie minérale, Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, 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, Cinétique, Kinetics, Cinética, Colorant organique, Organic dye, Colorante orgánico, Diffraction RX, X ray diffraction, Difracción RX, Hydroxyde de zinc, Zinc hydroxide, Zinc hidróxido, Hyperfréquence, Microwave, Hiperfrecuencia, Isotherme adsorption, Adsorption isotherm, Isotermo adsorción, Matériau poreux, Porous material, Material poroso, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Spectrométrie FTIR, Fourier-transformed infrared spectrometry, Espectrometría FTIR, Synthèse chimique, Chemical synthesis, Síntesis química, Synthèse combustion, Combustion synthesis, Nanostructured materials, Scanning electron microscopy, SEM, and X-ray diffraction

Zinc aluminum hydroxide (ZAH) as a porous adsorbent was synthesized using microwave assisted combustion method and its dye removal ability from single and binary systems was studied. The ZAH characteristics were investigated using XRD, FTIR, and SEM. Acid Blue 92(AB92), Acid Red 14 (AR14), and Direct Red 23 (DR23) were used. The effect of ZAH dosage and initial dye concentration on dye removal was investigated. Adsorption isotherm and kinetic was evaluated. The capacity of ZAH to remove AB92, AR14, and DR23 was 95 mg/g, 84 mg/g and 75 mg/g, respectively. Dye removal fitted with the Langmuir model and pseudo-second order kinetics.

Electronics, Electronique, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, 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, 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, Adsorbant organique, Organic adsorbent, Adsorbente orgánico, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Capacité adsorption, Adsorption capacity, Capacidad adsorción, Cinétique, Kinetics, Cinética, Colorant organique, Organic dye, Colorante orgánico, Composé inclusion, Inclusion compound, Compuesto inclusión, Cyclodextrine, Cyclodextrin, Ciclodextrina, Etude expérimentale, Experimental study, Estudio experimental, Iode, Iodine, Iodo, Milieu aqueux, Aqueous medium, Medio acuoso, Morphologie, Morphology, Morfología, Mécanisme formation, Formation mechanism, Mecanismo formacion, Mécanisme, Mechanism, Mecanismo, Nanofibre, Nanofiber, Nanofibra, Polymère conducteur, Conducting polymers, Polymérisation oxydante, Oxidative polymerization, Polimerizacion oxidante, Polymérisation sur matrice, Template polymerization, Polimerización sobre matriz, Préparation, Preparation, Preparación, Pyrrole polymère, Pyrrole polymer, Pirrol polímero, pH, Structure hiérarchique, Acid Red G, Adsorption, Hierarchical structure, and Polypyrrole (PPy)

The polypyrrole nano-fibers with hierarchical structure were synthesized in α-CD/I2 inclusion compound solution via chemical oxidation by using FeCl3 as the oxidant. The formation of the hierarchical structured PPy was certified by Field Emission Scanning Electronic Microscope (SEM). Fourier transform infrared spectroscopy (FT-IR) results showed that the molecular structure of the prepared PPy backbone is same as the conventional PPy. From the results of X-ray fluorescence spectrometer (XRF) and X-ray diffraction (XRD) measurements, the α-CD/I2-Fe2+ is as the soft-template during the synthesis process of PPy with hierarchical structure. Some I- ions retained in the backbone of the prepared PPy were as the counter ion after rinse. PPy with hierarchical structure shows very good adsorption performance for the Acid Red G (azo dye). The adsorption equilibrium time was very short (within 30min) and the maximum adsorption capacity (Qmax) was 121.95 mg/g, which is better than that of some other adsorbents reported in literatures. The hierarchical structured PPy that we prepared can be considered as a potential adsorbent for the removal of organic dyes from wastewater.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Agent surface, Surfactant, Agente superficie, Cinétique, Kinetics, Cinética, Huile, Oil, Aceite, Récupération, Recovery, Recuperación, Synthèse, Synthesis, Síntesis, Tension interfaciale, Interface tension, Tensión interfacial, EOR, interfacial tension, kinetics, and surfactants

The synthesis of CO2 philic surfactant using maleic anhydride and 4-tert-butylbenzyl alcohol is reported. We reacted maleic anhydride with 4-tert-butylbenzyl alcohol to form bis(4-(tert-butyl)benzyl) fumarate and sulfonated the produced diester. The esterification reaction was optimized for a maximum yield of 98% of bis(4-(tert-butyl)benzyl) fumarate. First-order reaction kinetics with respect to acid was observed. The activation energy was found to be 55.62 kJ/mol. The sulfonated product of diester was obtained by the sulfonation reaction and the yield of 82% of surfactant was achieved. The in-house developed surfactant effectively lowered down the IFT between CO2/brine to 4.2 mN/m. This surfactant is targeted for CO2-EOR applications.

General chemistry, physical chemistry, Chimie générale, chimie physique, Condensed state physics, Physique de l'état condensé, 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, Echange d'ions, Ion-exchange, Zéolites: préparations et propriétés, Zeolites: preparations and properties, Etat colloïdal et états dispersés, Colloidal state and disperse state, Matériaux poreux, Porous materials, Charbon, Coal, Carbón, Cinétique, Kinetics, Cinética, Cristallisation, Crystallization, Cristalización, Kaolinite, Caolinita, Matériau poreux, Porous material, Material poroso, Synthèse, Synthesis, Síntesis, Zéolite, Zeolite, Zeolita, Agent structurant, Template, Zéolite ZSM5, Coal-series kaolinite, Crystallization kinetics, Template free, and ZSM-5

Calcined coal-series kaolinite was used as a combinational Si and Al sources to synthesize ZSM-5 via an organic template-free method. The influence factors such as ball-milling time, H2O/SiO2 ratios, and NaOH/SiO2 ratios have been investigated systematically. Furthermore, crystallization kinetics experiments were performed at 170―190 °C for periods of time ranging from 6 to 96 h, and obtained the curves as a function of time. The obtained samples were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that ZSM-5 with excellent crystallinity could be obtained without organic template. Furthermore, mechanical treatment and synthesis conditions could influence the crystallinity and purity significantly. According to Arrhenius equation, the apparent activation energy for induction and growth were 78.3 and 68.5 kJ/mol, respectively.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Atomic molecular physics, Physique atomique et moléculaire, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, 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, Gel colloïdal, Colloidal gel, Gel coloidal, Acrylamide dérivé copolymère, Acrylamide derivative copolymer, Acrilamida derivado copolímero, Acrylamide polymère, Acrylamide polymer, Acrilamida polímero, Acrylique acide copolymère, Acrylic acid copolymer, Acrílico ácido copolímero, Cinétique, Kinetics, Cinética, Gonflement, Swelling, Inflamiento, Hydrogel, Hidrogel, hydrogel, kinetics, microgel, stimuli-responsive gels, and swelling

Composite hydrogels—macroscopic hydrogels with embedded microgel particles—are expected to respond to external stimuli quickly because microgels swell much faster than bulky gels. In this work, the kinetics of the pH-induced swelling of a composite hydrogel are studied using turbidity measurements. The embedded microgel is a pH- and thermosensitive poly(N-isopropylacrylamide-co-acrylic acid) microgel and the hydrogel matrix is polyacrylamide. A rapid pH-induced swelling of the embedded microgel particles is observed, confirming that composite hydrogels respond faster than ordinary hydrogels. However, compared with the free microgels, the swelling of the embedded microgel is much slower. Diffusion of OH- into the composite hydrogel film is identified as the main reason for the slow swelling of the embedded microgel particles, as the time of the pH-induced swelling of this film is comparable to that of OH- diffusion into the film. The composition of the hydrogel matrix does not significantly change the characteristic swelling time of the composite hydrogel film. However, the swelling pattern of the film changes with composition of the hydrogel matrix.

Inorganic chemistry, Chimie minérale, Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, 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, Cinétique, Kinetics, Cinética, Colorant organique, Organic dye, Colorante orgánico, Constante vitesse, Rate constant, Constante velocidad, Distribution concentration, Concentration distribution, Distribución concentración, Echange ion, Ion exchange, Cambio iónico, Eclairement, Illumination, Alumbrado, Epuration eau usée, Waste water purification, Depuración aguas servidas, Etain, Tin, Estaño, Nanocomposite, Nanocompuesto, Phosphate d'étain, Tin phosphate, Estaño fosfato, Photocatalyse, Photocatalysis, Fotocatálisis, Rayonnement visible, Visible radiation, Radiación visible, Styrène, Styrene, Estireno, Heterogeneous, and Ion exchange capacity

Styrene―tin (IV) phosphate nanocomposite (ST/TPNC) ion exchanger was used as efficient photocatalyst for the degradation of methylene blue dye from aqueous system in the presence of solar light. ST/TPNC exhibited a high efficiency in heterogeneous photocatalytic process for the removal of MB from the water system. The degradation efficiency after 2 h illumination was 80%. The degradation of MB follows the pseudo-first-order kinetics with rate constant 0.00702 min-1. The nanocomposite ion exchanger was explored for its ion exchange capacity, pH titration, elution behavior, elution concentration and distribution coefficient (Kd). ST/TPNC exhibited a higher ion exchange capacity (1.83 meg/g) compared to its inorganic counterpart (0.55 meg/g). ST/TPNC was characterized using some techniques such as Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and thermogravimetric analysis (TGA).

Crystallography, Cristallographie cristallogenèse, Chemical industry parachemical industry, Industrie chimique et parachimique, Metallurgy, welding, Métallurgie, soudage, 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, Traitement des matériaux et son effet sur la microstructure et les propriétés, Treatment of materials and its effects on microstructure and properties, Ecrouissage, durcissement par déformation; recuit, trempe, revenu, restauration et recristallisation; textures, Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures, 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, Elasticité. Plasticité, Elasticity. Plasticity, Rupture, Fractures, Contrôle, Analysing. Testing. Standards, Analyse des contraintes, Stress analysis, Analyse contrainte, Stress analysis, Análisis tensión, Spannungsanalyse, Cinétique, Kinetics, Cinética, Kinetik, Compression isotherme, Isothermal compression, Compresión isotérmica, Contrainte écoulement, Flow stress, Tensión flujo, Fliessspannung, Dissipation, Défaut cristallin, Crystal defect, Defecto cristalino, Déformation à chaud, Hot deformation, Deformación en caliente, Warmverformung, Dépendance température, Temperature dependence, Ecoulement plastique, Plastic flow, Flujo plástico, Plastisches Fliessen, Energie activation, Activation energy, Energía activación, Aktivierungsenergie, Equation constitutive, Constitutive equation, Ecuación constitutiva, Essai compression, Compression test, Ensayo compresión, Druckversuch, Fissuration, Cracking, Agrietamiento, Rissbildung, Instabilité, Instability, Inestabilidad, Unbestaendigkeit, Joint grain, Grain boundary, Limite grano, Korngrenze, Microstructure, Microestructura, Mikrogefuege, Modèle dynamique, Dynamic model, Modelo dinámico, Phase alpha, Alpha phase, Fase alfa, Alpha Phase, Phase bêta, Beta phase, Fase beta, Beta Phase, Plasticité, Plasticity, Plasticidad, Plastizitaet, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété plastique, Plastic properties, Propiedad plástica, Recristallisation dynamique, Dynamical recrystallization, Recristalización dinamica, Dynamische Rekristallisation, Relation contrainte déformation, Stress strain relation, Relación tensión deformación, Structure équiaxe, Equiaxed structure, Estructura equiaxial, Aequiaxiales Gefuege, Superplasticité, Superplasticity, Superplasticidad, Superplastizitaet, Titane alliage, Titanium alloy, Titanio aleación, Titanlegierung, Traitement matériau, Material processing, Tratamiento material, Travail à chaud, Hot working, Vitesse déformation, Strain rate, Velocidad deformación, Verformungsgeschwindigkeit, 0710P, 6172M, 8140E, 8140L, Hot deformation behavior, Processing map, and TC4-DT titanium alloy

Hot deformation behavior of TC4-DT alloy with an initial equiaxed α+β structure was investigated by conducting isothermal hot compression test in the deformation temperature range of 930-1020 °C and strain rate range of 0.001-10 s-1 with the maximum height reduction of 60%. The hot deformation behavior of TC4-DT alloy was characterized based on the analysis of the stress-strain behaviors, kinetics and processing map for obtaining optimum processing parameters and achieving desired microstructure during hot working. A constitutive equation by which the flow stress was expressed as a function of strain rate and deformation temperature was established and the apparent activation energy of deformation was calculated to be 644.642 kJ mol-1 in α + β phase region and 592.054 kJ mol-1 in β phase region. A processing map was constructed at the true strain of 0.9 based on dynamic materials model (DMM) to delineate the safe and unsafe regions in the axes of temperature and strain rate. Two regions were marked as unsafe with one in α + β phase field and the other in β phase field and both were in strain rate higher than 1 s-1. These instability domains exhibited localized plastic flow and cracking along grain boundaries which should be taken care of during hot processing. The stable domain covered through the whole temperatures under strain rate of 1 s-1 with peaks in power dissipation of 41% and 39% which indicated superplasticity (SP) and dynamic recrystallization (DRX). Microstructure observation of the deformed specimens validated the applicability of the processing map at obtaining the optimum processing parameters of TC4-DT alloy.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Biomasse, Biomass, Biomasa, Biosorption, Biosorción, Chimie physique, Physical chemistry, Fisicoquímica, Cinétique, Kinetics, Cinética, Equilibre, Equilibrium, Equilibrio, Mécanisme, Mechanism, Mecanismo, Spectrométrie IR, Infrared spectrometry, Espectrometría IR, Azure A, FTIR, Zea mays, and biosorption

The mechanism of Azure A (AA) biosorption by Zea mays biomass (ZMB) was studied. Surface chemistry and morphology were characterized by potentiometric titration, pH of zero charge, FTIR, and microscope analysis. The equilibrium data was modeled by Langmuir, Freundlich, Redlich-Peterson, Temkin, and multilayer models. AA biosorption was mainly limited by chemisorption, but the role of intraparticle diffusion could not be neglected. The integrative analysis of surface chemistry/biosorption studies showed that chemisorption, ion exchange, complexation, and/or electrostatic attraction were involved during AA biosorption. The maximum biosorption capacity of ZMB (q 5.84 mg/g) was registered at pH7.6.

Crystallography, Cristallographie cristallogenèse, Chemical industry parachemical industry, Industrie chimique et parachimique, Metallurgy, welding, Métallurgie, soudage, 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, Diagrammes de phases et microstructures développées par solidification et par transformations de phases solide-solide, Phase diagrams and microstructures developed by solidification and solid-solid phase transformations, Transformations martensitiques, Martensitic transformations, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements thermiques, Heat treatment, Trempe et revenu, Hardening. Tempering, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Acier, Steel, Acero, Austénite résiduelle, Retained austenite, Austenita residual, Restaustenit, Champ déformation, Strain distribution, Campo deformación, Cinétique, Kinetics, Cinética, Kinetik, Diffraction RX, X ray diffraction, Difracción RX, Roentgenbeugung, Diffraction électron rétrodiffusé, EBSD, Diffractión electrón retrodifusa, Distribution contrainte, Stress distribution, Campo restricción, Mechanisches Spannungsfeld, Déformation plastique, Plastic deformation, Deformación plástica, Plastische Verformung, Dépendance du temps, Time dependence, Dependencia del tiempo, Grande déformation, High strain, Gran deformación, Interface, Interfase, Grenzflaeche, Martensite, Martensita, Martensit, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Rasterelektronenmikroskopie, Microstructure, Microestructura, Mikrogefuege, Propriété mécanique, Mechanical properties, Propiedad mecánica, Relation structure propriété, Property structure relationship, Relación estructura propiedad, Sous grain, Subgrain, Subgrano, Subkorn, Transformation bainitique, Bainitic transformation, Transformación bainítica, Bainitische Umwandlung, Transformation martensitique, Martensitic transformation, Transformación martensítica, Martensitische Umwandlung, Trempe, Quenching, Temple, Abschrecken, 8130K, Bainite transformation, Grain rotation, and Quenching and partitioning

This paper presents a detailed characterization of the microstructural evolution of quenching and partitioning (Q&P) steel by dilatometer, X-ray diffraction and scanning electron microscopy. Influence of partitioning time on mechanical properties was investigated and the relationship between microstructures and mechanical properties was established. The results indicate that bainite transformation occurs at the preliminary stage of partitioning and the amount is proportional to quenching temperature. Martensite softening, bainite transformation kinetics, amount and stability of retained austenite collaboratively have effects on mechanical properties. The purpose of the EBSD investigation is to study the changes in the microstructure of the Q&P steel during deformation and obtain a better understanding of collaborative deformation-transformation behavior. During deformation, plastic deformation preferentially occurred in the vicinity of ferrite-martensite interfaces and spread to the interior of ferrite grain with strain increasing. Plastic deformation started to occur in martensite after large strain. Furthermore, grain rotation occurred in some austenite grains or divided into subgrains during deformation.

Inorganic chemistry, Chimie minérale, Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, 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, Traitement des matériaux et son effet sur la microstructure et les propriétés, Treatment of materials and its effects on microstructure and properties, Autres traitements thermiques et thermomécaniques, Other heat and thermomechanical treatments, 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, Elasticité. Plasticité, Elasticity. Plasticity, Alliage base aluminium, Aluminium base alloys, Alliage moulé, Cast alloy, Aleación moldeada, Gusslegierung, Charge cyclique, Cyclic load, Carga cíclica, Zyklische Belastung, Cinétique, Kinetics, Cinética, Kinetik, Ductilité, Ductility, Ductilidad, Verformungsfaehigkeit, Dureté, Hardness, Dureza, Haerte, Limite élasticité, Yield strength, Límite elasticidad, Streckgrenze, Microstructure, Microestructura, Mikrogefuege, Précipité, Precipitate, Precipitado, Ausscheidungsprodukt, Recuit mise en solution, Solution heat treatment, Recocido disolución, Loesungsgluehen, Résistance traction, Tensile strength, Resistencia tracción, Zugfestigkeit, Silicium alliage, Silicon alloy, Silicio aleación, Siliciumlegierung, Vieillissement, Ageing, Envejecimiento, Altern, Zone Guinier Preston, Guinier Preston zone, Zona Guinier Preston, Guinier Preston Zone, Age hardening, Al-Si-Cu-Mg alloy, Dilatometer analysis, High-temperature mechanical properties, and Zr-V-Ti additions

A hypoeutectic Al-Si based alloy with Cu, Mg and additions of Zr, V and Ti, was evaluated to determine its suitability for applications at higher temperatures. The as-cast alloy consists of α-Al matrix, Al-Si eutectic and Al2Cu, Al5Mg9Si8Cu2 and Al14Mg4FeSi6/Al5FeSi, intermetallic phases, plus two distinct Zr-V-Ti-based phases. Solutionizing treatment leads to dissolution of Al5Mg8Si6Cu2 and Al2Cu and the partial dissolution of Zr-V-Ti-based intermetallics. Integration of aging kinetics with mechanical properties data allowed to establish different aging parameters leading to T6 peak-aging and T7 over-aging conditions corresponding to hardness of 96 and 68 HRF respectively. T7 condition enabled higher hardness retention than T6 condition; the alloy softening was observed at 260 °C versus 240 °C after T6 treatment. TEM characterization of the alloy in the T6 condition revealed GP zones, and rod-shaped trialuminide Al3(Zr, V, Ti) with average size of 230 nm as well as S-phase (Al2CuMg) precipitates. After T6 treatment followed by isothermal annealing at 475 °C, the alloy showed hardness retention improvement by approximately 30%. Subsequent TEM analysis revealed a higher density of the Al3(Zr, V, Ti) rod-shaped precipitates along with formation of new lath shaped Q'-phase AlSiCuMg precipitates. Two over-aging reactions between 250-350 °C and 440-460 °C were associated with the stability of Cu-Mg and Al-Zr-V-Ti based nanoprecipitates respectively. Temperature of 250 °C was established as the transition temperature above which degradation of mechanical properties was observed from UTS of approximately 311 MPa at room temperature to 208 MPa at 250 °C. The results indicate that additions of Zr, V and Ti improve yield strength and cyclic yield strength at room temperature but lower ductility, while slightly improve elevated temperature hardness with almost no effect on tensile strength.

Inorganic chemistry, Chimie minérale, Crystallography, Cristallographie cristallogenèse, Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Combustibles de remplacement. Production et utilisation, Alternative fuels. Production and utilization, Hydrogène, Hydrogen, Analyse structurale, Structural analysis, Análisis estructural, Cinétique, Kinetics, Cinética, Cobalt alliage, Cobalt alloy, Cobalto aleación, Déshydrogénation, Dehydrogenation, Deshidrogenación, Effet température, Temperature effect, Efecto temperatura, Enthalpie, Enthalpy, Entalpía, Hydrogénation, Hydrogenation, Hidrogenación, Lanthanide alliage, Rare earth metal alloy, Lantánido aleación, Métal transition alliage, Transition metal alloy, Metal transición aleación, Phase bêta, Beta phase, Fase beta, Phase gamma, Gamma phase, Fase gamma, Réaction interface, Interface reaction, Reacción interfase, Samarium alliage, Samarium alloy, Samario aleación, Stockage hydrogène, Hydrogen storage, Sm2Co7, and Thermodynamics

The structural characteristics and hydrogen-storage properties of the Ce2Ni7-type compound Sm2Co7 have been investigated for the first time. This alloy transforms to the β phase and then the γ phase upon hydrogenation. These two phases have been identified as Sm2Co7H2.9 and Sm2Co7H6.4, and their dehydrogenation enthalpies have been measured as 48.5 and 42.0 kJ/mol H2, respectively. Sm2Co7 shows excellent stability without obvious capacity loss after 50 cycles, and its hydrogenation process follows a three-dimensional-interface-controlled reaction at ambient temperature.

Crystallography, Cristallographie cristallogenèse, Chemical industry parachemical industry, Industrie chimique et parachimique, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements thermiques, Heat treatment, Trempe et revenu, Hardening. Tempering, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Autres propriétés mécaniques, Other mechanical properties, Anisotropie, Anisotropy, Anisotropía, Cinétique, Kinetics, Cinética, Kinetik, Contrainte compression, Compressive stress, Tensión compresión, Druckspannung, Contrainte flexion, Bending stress, Tensión flexión, Contrainte résiduelle, Residual stress, Tensión residual, Eigenspannung, Contrainte superficielle, Surface stresses, Contrainte thermique, Thermal stress, Tensión térmica, Waermespannung, Contrainte traction, Tensile stress, Tensión traccíon, Zugspannung, Couche contrainte, Strained layer, Capa forzada, Durcissement, Hardening, Endurecimiento, Haerten, Echange ion, Ion exchange, Cambio iónico, Ionenaustausch, Effet contrainte, Stress effects, Epaisseur, Thickness, Espesor, Dicke, Fibre verre, Glass fiber, Fibra vidrio, Flexion, Bending, Flexión, Biegung, Plan expérience, Experimental design, Plan experiencia, Relaxation contrainte, Stress relaxation, Relajación tensión, Spannungsrelaxation, Relaxation structurale, Structure relaxation, Relajación estructural, Renforcement mécanique, Strengthening, Refuerzo mecánico, Revenu, Tempering, Silice, Silica, Sílice, Structure verre, Glass structure, Temps relaxation, Relaxation time, Tiempo relajación, Traitement thermique, Heat treatment, Tratamiento térmico, Waermebehandlung, Verre, Glass, Vidrio, Glas, E glass, Fiber, Relaxation, and Stress

Earlier, a new glass strengthening method was demonstrated using silica glass fiber. The method involved heat-treatment of a glass while held under a sub-critical tensile stress. The added strength was attributed to the formation of a compressive stress layer on the surface created by a surface stress relaxation process. This new glass strengthening method does not require glass of finite thickness, as in tempering, or glass containing alkali ions, as in ion-exchange. The same method was applied to E-glass fibers by treating the fibers under 1 and 2 GPa stresses at 200 °C for 60 s in air and a strength increase of ~0.6 GPa was achieved. The extent of the surface residual stress formation was estimated from the permanent bending kinetics of glass fibers heated under bending stresses and released. In the present work, the origin of the strengthening is attributed to the surface compressive stress rather than an anisotropic structure of the glass. The stability of the residual surface stress produced was estimated by measuring the kinetics of unbending of bent fibers at 325-425 °C in air. The relaxation time of the surface stress release at room temperature in air was estimated to be at least 1 to 3 years.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Atomic molecular physics, Physique atomique et moléculaire, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Cinétique, Kinetics, Cinética, Formation motif, Patterning, Formacíon motivo, Lithographie, Lithography, Litografía, Nanostructure, Nanoestructura, Nanotechnologie, Nanotechnology, Nanotecnología, Procédé thermochimique, Thermochemical processes, Vitesse déplacement, Speed, Velocidad desplazamiento, kinetics, lithography, nanostructures, nanotechnology, and thermochemistry

Thermochemical nanolithography (TCNL) is a high-resolution lithographic technique and, owing to its fast speed, versatility, and unique ability to fabricate arbitrary, gray-scale nanopatterns, this scanning probe technique is relevant both for fundamental scientific research as well as for nanomanufacturing applications. In this work, we study the dependence of the TCNL driven chemical reactions on the translation speed of the thermal cantilever. The experimental data compares well with a model of the chemical kinetics for a first-order reaction. The impact of higher order reactions on the optimization of TCNL is addressed. The reported quantitative description of the speed dependence of TCNL is exploited and illustrated by fabricating controlled gradients of chemical concentration.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, 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, Etat colloïdal et états dispersés, Colloidal state and disperse state, Métal transition, Transition metal, Metal transición, Adsorbant, Adsorbent, Adsorbente, Adsorption, Adsorción, Cinétique, Kinetics, Cinética, Eau usée, Waste water, Agua residual, Isotherme, Isotherm, Isoterma, Platine, Platinum, Platino, Séparation, Separation, Separación, Balle de riz, Rice husk, Cáscara de arroz, isotherms, kinetics, platinum, and rice husk

Some novel adsorbents were prepared by rice husk (RH). The esterified rice husk (RHS) was prepared by treating RH with anhydride of succinic acid to introduce carboxylic function to rice husk. This RHS was used to anchor various polyamines, viz., ethylenediamine (ED) and diethylenetriamine (DT) to prepare new adsorbents. These adsorbents were used to separate Pt(IV) from synthetic as well as industrial wastewaters. Adsorbents were characterized by Fourier transform infrared spectra, elemental analysis, scanning electron microscopy, and energy dispersive x-ray spectrometry. The selectivity order for Pt(IV) removal found was: RHS-DT > RHS-ED > RH > RHS. The Freundlich isotherm provided the high correlation (0.9750-0.9938) for the adsorption with low SSE (0.00215-0.00785) value of Pt(IV) for all the adsorbents. Among the kinetic models, pseudo-second order kinetic model was found to best fit with high correlation for all the adsorbents. The results of thermodynamic parameters suggest that the Pt(IV) adsorption was spontaneous and endothermic in nature. The maximum percentage of desorption of Pt(IV) metal ion was obtained when the reagent HCI-thiourea mixture was used as desorbing agent.

Metallurgy, welding, Métallurgie, soudage, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Généralités, General, Anomalie, Anomaly, Anomalía, Cinétique, Kinetics, Cinética, Kinetik, Densité, Density, Densidad, Diffusion, Difusión, Modélisation, Modeling, Modelización, Propriété magnétique, Magnetic properties, Propiedad magnética, Magnetische Eigenschaft, Transformation ordre désordre, Order disorder transformation, Transformación desorden-orden, Ordnungsumwandlung, Density functional theory (DFT), and Theory and modeling (kinetics, transport, diffusion)

The temperature (T) dependent self-diffusion coefficients (D) in Fe and Co are calculated from first-principles, across the Curie temperature (Tc), employing a density functional theory approach based on a recently developed spin-wave method for modeling the paramagnetic state. Calculated results for D(T) are shown to accurately reproduce measured values for T/Tc ranging from 0.7 to 1.1, including the anomaly in the Arrhenius plot for Fe near Tc. An analysis of calculated results in Mn, Fe and Co suggests that the magnitude of the effect of magnetic disorder on D is correlated with d band filling and the transition from weak to strong ferromagnetism.