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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, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Combustibles de remplacement. Production et utilisation, Alternative fuels. Production and utilization, Hydrogène, Hydrogen, Métal transition, Transition metal, Metal transición, Platinoïde, Platinoid, Platinoide, Carbone, Carbon, Carbono, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Catalyseur, Catalyst, Catalizador, Hydrogénation, Hydrogenation, Hidrogenación, Hydrure, Hydrides, Hidruro, Hétérocycle, Heterocyclic compound, Heterociclo, Liquide, Liquid, Líquido, Protection environnement, Environmental protection, Protección medio ambiente, Ruthénium, Ruthenium, Rutenio, Réaction catalytique, Catalytic reaction, Reacción catalítica, Réactivité chimique, Chemical reactivity, Reactividad química, Stockage hydrogène, Hydrogen storage, Structure, Estructura, Substitution, Substitución, Heterocyclic compounds, Liquid organic hydride, and Ruthenium catalysts

The effect of the type of heteroatom in the structure on the recyclability of possible candidate compounds for application as LOC (liquid organic carriers) was studied by comparing the rate and selectivity obtained in hydrogenation of carbazole, dibenzothiophene, dibenzofuran and fluorene. The effect of a partial saturation of the compound on its hydrogenation yield and reaction pathway was also considered by studying hydrogenation of 1,2,3,4-tetrahydrocarbazole. Using Ru black catalyst, the rate of hydrogenation was found to decrease in order; dibenzofuran > 1,2,3,4-tetrahydrocarbazole > carbazole » fluorene. No reaction was observed in the hydrogenation of dibenzothiophene under the conditions studied which was attributed to the immediate poisoning of ruthenium metal by sulphur compounds. The rate of hydrogenation of fluorene was around 3 times lower as compared to carbazole and over 8 times lower as compared to that of dibenzofuran under the same reaction conditions. With the exeption of S containing dibenzothiophene, the presence of the heteroatom in the structure was found to be beneficial in terms of increasing the rate of hydrogen loading step. Additionally, a higher reaction rate was obtained in the hydrogenation of the partially saturated 1,2,3,4-tetrahydrocarbazole as compared to the substrate carbazole. The structure and stability of intermediates was found to be significantly influenced by the type and presence of a heteroatom in the structure. A stable octahydro-intermediate was observed only with N-heterocycles, whereas a stable hexahydro-intermediate was produced in the polyaromatic hydrocarbon-fluorene. Additionally, the theoretically obtained lowest total enthalpies using DFT calculations agreed well with the stable intermediates observed experimentally in the hydrogenation of fluorene. Theoretical DFT differences in enthalpies also indicated the products of hydrogenolysis of perhydro-dibenzofuran to be the most favourable products of its hydrogenation, which agreed well with the experimental observations. Overall, taking into account the recyclability of LOC, substitution of carbon with a N heteroatom was demonstrated to be one of the promising approaches to improve the kinetics of the hydrogen loading step.

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, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Métal transition, Transition metal, Metal transición, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Catalyseur, Catalyst, Catalizador, Durabilité, Durability, Durabilidad, Oxygène, Oxygen, Oxígeno, Palladium, Paladio, Pile combustible, Fuel cell, Pila combustión, Platine, Platinum, Platino, Platinoïde, Platinoid, Platinoide, Protection environnement, Environmental protection, Protección medio ambiente, Préparation, Preparation, Preparación, Réduction chimique, Chemical reduction, Reducción química, Structure, Estructura, Yttrium, Ytrio, Core-shell-shell structure, and Oxygen reduction reaction

A core-shell-shell structure Pd-Y-Pt/C catalyst was prepared using a controlled surface reaction method. The structure was confirmed by X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray (EDX) techniques. Nano-scale yttrium was formed as a shell located as the middle layer of the catalyst. Electrochemical evaluation of the Pd-Y-Pt/C with less than 7% of Pt showed an improved performance toward oxygen reduction reaction (ORR) compared to Pt/C (20wt.% Pt). Accelerated degradation tests (ADT) indicated that the addition of Y improved catalyst stability compared to Pt/C and Pd-Pt/C core-shell catalysts under various experimental conditions. This was due to the Y middle layer created approximate half-filled metal-metal d bond between Pt (or Pd) and Y. This catalyst utilized the core-shell-shell structure to minimize the Pt usage, and Y middle shell to improve stability.

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, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Défaut, Defect, Defecto, Nanotube carbone, Carbon nanotubes, Oxygène, Oxygen, Oxígeno, Pile combustible, Fuel cell, Pila combustión, Protection environnement, Environmental protection, Protección medio ambiente, Réaction catalytique, Catalytic reaction, Reacción catalítica, Réduction chimique, Chemical reduction, Reducción química, CNTs, Defects, Fuel cells, NPMCs, and ORR

Non-precious metal catalysts for the oxygen reduction reaction (ORR) based upon the incorporation of different amounts of N into the C—C network of multiwalled carbon nanotubes (CNTs) have been prepared by using CNTs and urea as the carbon and nitrogen sources, respectively. First, and with the aim of generating different levels of defects in the carbon network, the CNTs have been subjected to ballmilling during different periods of time between 0 and 150 h. Then, urea was mixed with the treated CNTs, subjected to further ballmilling and pyrolized at 800°C. The number of defects, and as a consequence, the amount of N incorporated into the CNTs, increases with the duration of the ballmilling time. Moreover, the structure of the CNTs obtained after longer ballmilling times collapses leading to a carbon material with a high degree of microporisity. The performance of the N/CNT for the ORR, in terms of both the onset potential and mass current activity, increases with the amount of N actually incorporated into the CNT. Moreover, the H2O2 formation during ORR varies with the morphology of the catalyst. Thus, the formation of H2O2 is favored with the electrocatalysts in which the CNT structure is preserved, whereas the total reduction of O2 to H2O is favored for the electrocatalysts in which micropores are formed.

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, Electrochimie, Electrochemistry, Cinétique et mécanisme des réactions, Kinetics and mechanism of reactions, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Alcanol, Alkanol, Alcool, Alcohol, Métal transition, Transition metal, Metal transición, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Electrocatalyse, Electrocatalysis, Electrocatálisis, Hydroxyde de potassium, Potassium hydroxide, Potasio hidróxido, Hyperfréquence, Microwave, Hiperfrecuencia, Irradiation hyperfréquence, Microwave irradiation, Irradiación hiperfrecuencia, Méthanol, Methanol, Metanol, Nanoparticule, Nanoparticle, Nanopartícula, Nickel, Niquel, Noir carbone, Carbon black, Carbón negro, Oxydation, Oxidation, Oxidación, Pile combustible, Fuel cell, Pila combustión, Protection environnement, Environmental protection, Protección medio ambiente, Fuel cells, KOH, and Nickel-based electrocatalyst

Ni/C electrocatalysts were prepared by chemical deposition of nickel nanoparticles on Vulcan XC-72R carbon black using microwave irradiation technique. The time of microwave irradiation during the reduction step and nickel weight percentage were varied. This was found to affect the morphology of formed Ni/C powder as shown by TEM analysis. Increasing nickel weight percentage results in the formation of more aggregated deposits. The electrocatalytic activity of different Ni/C samples towards methanol oxidation reaction in KOH solution was studied by applying cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopic techniques. Ni/C electrocatalyst containing 30wt.% Ni [Ni/C-30] shows 5.2 times higher electrocatalytic activity than that with 10 wt.% Ni [Ni/C-10]. Heating Ni/C powder into microwave oven using the pulse mode of 30s on/10s off forms the most stable electrocatalyst for prolonged oxidation reaction. Electrochemical impedance measurements show that Ni/C-30 electrocatalyst has the lowest impedance value of 0.022 kΩ cm2, while the highest one is for Ni/C-10 [0.331 kΩ cm2] in (0.4 M methanol + 0.5 M KOH) solution at 500 mV. It confirms that Ni/C-30 has the highest electrocatalytic activity towards methanol oxidation reaction.

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, Etat colloïdal et états dispersés, Colloidal state and disperse state, Matériaux poreux, Porous materials, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Métal transition, Transition metal, Metal transición, Carbone, Carbon, Carbono, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Catalyseur, Catalyst, Catalizador, Croissance, Growth, Crecimiento, Dynamique moléculaire, Molecular dynamics, Dinámica molecular, Dépôt, Deposition, Depósito, Electrode, Electrodes, Electrodo, Etude expérimentale, Experimental study, Estudio experimental, Matériau poreux, Porous material, Material poroso, Pile combustible, Fuel cell, Pila combustión, Plasma, Platine, Platinum, Platino, Protection environnement, Environmental protection, Protección medio ambiente, Pulvérisation irradiation, Sputtering, Pulverización irradiación, Cluster growth, Fuel cell electrodes, Plasma sputtering deposition, and Pt catalyst

Amorphous platinum clusters supported on porous carbon have been envisaged for high-performance fuel cell electrodes. For this application, it is crucial to control the morphology of the Pt layer and the Pt-substrate interaction to maximize activity and stability. We thus investigate the morphology evolution during Pt cluster growth on a porous carbon substrate employing atomic scale molecular dynamics simulations. The simulations are based on the Pt-C interaction potential using parameters derived from density functional theory and are found to yield a Pt cluster morphology similar to that observed in low loaded fuel cell electrodes prepared by plasma sputtering. Moreover, the simulations show amorphous Pt cluster growth in agreement with X-ray diffraction and transmission electron microscopy experiments on high performance low Pt content (10 μgPt cm-2) loaded fuel cell electrodes and provide a fundamental insight in the cluster growth mechanism.

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, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Acide carboxylique, Carboxylic acid, Acido carboxílico, Composé de métal de transition, Transition element compounds, Acide formique, Formic acid, Fórmico ácido, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Catalyseur, Catalyst, Catalizador, Matériau hybride, Hybrid material, Material híbrido, Oxyde de titane, Titanium oxide, Titanio óxido, Pile combustible, Fuel cell, Pila combustión, Protection environnement, Environmental protection, Protección medio ambiente, Support catalyseur, Catalyst support, Soporte catalizador, Fuel cells, Pd-based catalysts, and TiO2-C hybrids

The electrooxidation of formic acid was performed on Pd-based catalysts supported on hybrid TiO2-C materials prepared from different carbon origins by solvothermal and slurry synthesis. It has been found that carbonized hybrid TiO2-C supports with mesopore texture and high anatase:rutile ratio in the TiO2 framework led to about three times higher activity per Pd mass unit than the catalyst prepared on a commercial Vulcan XC-72 carbon black, which will allow to reduce considerably the amount of expensive noble metal at the anode of DFAFC. The conductivities of raw TiO2/C supports are several orders of magnitude lower than that for carbon Vulcan XC-72. However, the hybrid TiO2-C supports acquire high conductivity during palladium deposition. The rate of electrooxidation of formic acid on Pd/TiO2-C catalysts, calculated per one surface Pd atom (TOF), is for TOF < 1 S-1 independent of Pd particle size and morphology of the supports. Higher activity of the Pd/TiO2-C catalysts, compared to Pd/C catalyst, results from their higher hydrophilicity which ensures good access of formic acid to the Pd crystallites in the catalyst layer, and sufficiently high conductivity providing easy electron flow from the Pd active sites to current collector. Present results indicate that hybrid inorganic/organic materials are promising supports for the direct formic acid fuel cells with Pd-based catalysts.

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, Electrochimie, Electrochemistry, Cinétique et mécanisme des réactions, Kinetics and mechanism of reactions, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Métal transition, Transition metal, Metal transición, Carbone, Carbon, Carbono, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Electrocatalyse, Electrocatalysis, Electrocatálisis, Electrochimie, Electrochemistry, Electroquímica, Nanoparticule, Nanoparticle, Nanopartícula, Nanotube carbone, Carbon nanotubes, Nanotube multifeuillet, Multiwalled nanotube, Nanotubo pared múltiple, Oxygène, Oxygen, Oxígeno, Pile combustible, Fuel cell, Pila combustión, Platine, Platinum, Platino, Protection environnement, Environmental protection, Protección medio ambiente, Réduction chimique, Chemical reduction, Reducción química, Stabilité, Stability, Estabilidad, Electrochemical stability, Oxygen reduction reaction, and Platinum nanoparticles

A non-covalent functionalization for multi-walled carbon nanotubes has been used as an alternative to the damaging acid treatment. Platinum nanoparticles with similar particle size distribution have been deposited on the surface modified multi-walled carbon nanotubes. The interaction between platinum nanoparticles and multi-walled carbon nanotubes functionalized with 1-pyrenecarboxylic acid is studied and its electrochemical stability investigated. This study reveals the existence of a platinum-support interaction and leads to three main conclusions. First, the addition of 1-pyrenecarboxylic acid is improving the dispersion of platinum nanoparticles, leading to an improved electrochemical activity towards oxygen reduction reaction. Second, the investigations regarding the electrochemical stability showed that the platinum-support interaction plays an important role in improving the long-term stability by as much as 20%. Third, post-mortem microscopy analysis showed a surprising effect. During the electrochemical stability investigations concerned with carbon corrosion it was found that the multi-walled carbon nanotubes were undergoing severe structural change, transforming finally into carbon spheres.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, 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, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Protéines, Proteins, Aliment, Food, Alimento, Application, Aplicación, Biopolymère, Biopolymer, Biopolímero, Encapsulation, Encapsulación, Libération, Release, Liberación, Micronutriment, Micronutrient, Micronutriente, Microstructure, Microestructura, Nanostructure, Nanoestructura, Particule colloïdale, Colloid particle, Partícula coloidal, Protéine, Protein, Proteína, Vecteur médicament, Drug carrier, Vector medicamento, Zéine, Zein, Zeina, Biopolymers, Colloidal particles, and Controlled release

The application of colloidal particles from natural materials for purposes ranging from the delivery of bioactives to interfacial stabilisation and bulk structuring have recently gained a lot of interest for applications in the field of fast moving consumer goods, nutraceuticals, agricultural formulations and medicine. Zein-a proline rich water insoluble protein obtained from natural and sustainable source has been recently researched to generate colloidal structures that can find a wide range of applications. In this paper, we review the recent progress in the preparation of colloidal structures and their further application as functional materials in the field of delivery of functional ingredients and structuring of bulk phases and interfaces.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, 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, Divers, Miscellaneous, Analyse chimique, Chemical analysis, Análisis químico, Biocarburant, Biofuel, Biocarburante, Combustible remplacement, Alternative fuel, Combustible reemplazamiento, Combustion, Combustión, Hydrocarbure, Hydrocarbon, Hidrocarburo, Indice cétane, Cetane number, Indice cetano, Relation structure propriété, Property structure relationship, Relación estructura propiedad, Sesquiterpène, Sesquiterpenes, Sesquiterpeno, Terpénoïde, Terpenoid, Terpenoide, Farnésane dérivé, Alternative diesel fuel, Combustion properties, Farnesane, Surrogate fuel, and Trimethyl dodecane

The global combustion characteristics of 2,6,10-trimethyl dodecane (trimethyl dodecane), a synthetic fuel candidate species, have been experimentally investigated by measuring extinction limits for strained laminar diffusion flames at 1 atm and reflected shock ignition delays at 20 atm. The Derived Cetane Number (DCN) of trimethyl dodecane, (59.1) and Hydrogen/Carbon (H/C) ratio (2.133) are very close to the DCN and H/C ratio of a previously studied synthetic aviation fuel, S-8 POSF 4734 (S-8) and its surrogate mixture composed of n-dodecane/iso-octane (58.9 and 2.19, respectively). Identical high temperature global kinetic reactivities are observed in all experiments involving the aforementioned compounds. However, at temperatures below ~870 K, the S-8 surrogate mixture has ignition delay times approximately a factor of two faster. A chemical functional group analysis identifies that the methylene (CH2) to methyl (CH3) ratio globally correlates the low temperature alkylperoxy radical reactivity for these large paraffinic fuels. This result is further supported experimentally, by comparing observations using a surrogate fuel mixture of n-hexadecane (n-cetane) and 2,2,4,4,6,8,8-heptamethyl nonane (iso-cetane) that shares the same methylene-to-methyl ratio as trimethyl dodecane, in addition to the same DCN and H/C ratio. Measurements of both diffusion flame extinction and reflected shock ignition delays show that the n-cetane/iso-cetane model fuel has very similar combustion behavior to trimethyl dodecane at all conditions studied. A kinetic modeling analysis on the model fuel suggests the formation of alkylhydroperoxy radicals (QOOH) to be strongly influenced by the absence or presence of the methyl and methylene functional groups in the fuel chemical structure. The experimental observations and analyses suggest that paraffinic based fuels having high DCN values may be more appropriately emulated by further including the CH2 to CH3 ratio as an additional combustion property target, as DCN alone fails to fully distinguish the relative reaction characteristics of low temperature kinetic phenomena.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Etudes théoriques. Données et constantes. Mesures, Theoretical studies. Data and constants. Metering, Combustion. Flammes, Combustion. Flame, Combustion des combustibles liquides, Combustion of liquid fuels, Alcool, Alcohol, Analyse image, Image analysis, Análisis imagen, Biocarburant, Biofuel, Biocarburante, Butanol, Dimension particule, Particle size, Dimensión partícula, Distribution dimension particule, Particle size distribution, Distribución dimensión partícula, Dodécane, Dodecane, Dodecano, Hydrocarbure, Hydrocarbon, Hidrocarburo, Microscopie électronique transmission, Transmission electron microscopy, Microscopía electrónica transmisión, Morphologie, Morphology, Morfología, Mélange carburant, Fuel mixture, Mezcla carburante, Nanostructure, Nanoestructura, Oxydation, Oxidation, Oxidación, Stabilité, Stability, Estabilidad, Structure surface, Surface structure, Estructura superficie, Suie, Soot, Hollín, Soot nanostructure, Sooting stability, Sooting tendency, n-Butanol, and n-Dodecane

This work focuses on understanding the formation and oxidation of soot when adding n-butanol, an oxygenated fuel, to n-dodecane. A two-stage burner was used to characterize the oxidation of soot from different n-butanol blends, 10%, 30%, and 60 mol% in n-dodecane. The two-stage burner isolates the soot oxidation process from the formation process. Soot is formed in a first-stage premixed burner under fuel-rich conditions, while in a second stage, the soot is oxidized under slightly fuel-rich conditions. A scanning mobility particle sizer (SMPS) was used to measure the soot particle size distributions in the flame at different heights during oxidation. Results showed a decrease in particle mass concentration (g/cm3) as the fraction of n-butanol increased, which indicates the capability of n-butanol to reduce soot particle number and mass. On the other hand, the results demonstrated that the increasing n-butanol reduces the difference between initial mass of soot particles entering and the final mass of soot particles leaving the second burner. This result implies that increasing the n-butanol concentration decreases the rate of soot oxidation. Two different fuel quality indicators are used to quantify our observations. The first one, sooting tendency, is calculated to show how the amount of soot formed in the flame is affected by using different n-butanol percentages. The second one, sooting stability, is defined for quantifying the stability of soot particles against oxidation. The results demonstrated that by increasing the n-butanol percentage, soot formation was suppressed. However, sooting stability increased with higher concentrations of n-butanol. The soot nanostructure was quantified by high-resolution electron microscopy and digital image processing. Image analysis revealed layer arrangement is in correlation with sooting stability. The results of interlayer spacing showed a decrease by increasing n-butanol at the same sampling height.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, 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, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Protéines, Proteins, Agrégation, Aggregation, Agregación, Article synthèse, Review, Artículo síntesis, Biothérapie, Biotherapy, Bioterapia, Caractérisation, Characterization, Caracterización, Particule, Particle, Partícula, Protéine, Protein, Proteína, Rhéologie, Rheology, and Reología

In this review, we attempt to give a concise overview of recent progress made in mechanistic understanding of protein aggregation, particulate formation and protein solution rheology. Recent advances in analytical techniques and methods for characterizing protein aggregation and the formed protein particles as well as advancements, technique limitations and controversies in the field of protein solution rheology are discussed. The focus of the review is primarily on biotherapeutics and proteins/antibodies that are relevant to that area. As per the remit of Current Opinion in Colloid and Interface Science, here we attempt to stimulate interest in areas of debate. While the field is certainly not mature enough that all problems may be considered resolved and accepted by consensus, we wish to highlight some areas of controversy and debate that need further attention from the scientific community.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, 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, Emulsions. Microémulsions. Mousses, Emulsions. Microemulsions. Foams, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Amidon, Starch, Almidón, Article synthèse, Review, Artículo síntesis, Biopolymère, Biopolymer, Biopolímero, Cellulose, Celulosa, Chitine, Chitin, Quitina, Emulsion, Emulsión, Lignine, Lignin, Lignina, Mousse (émulsion), Foam, Espuma, Particule, Particle, Partícula, Protéine, Protein, Proteína, Stabilisation, Stabilization, Estabilización, Biologically derived particles, Emulsions, Foams, and Pickering

The focus in the study of Pickering foams and emulsions has recently been shifting from using inorganic particles to adopting particles of biological origin for stabilization. This shift is motivated by the incompatibility of some inorganic particles for food and biomedical applications, as well as their poor sustainability. This review focuses on major developments in foams and emulsions stabilized by particles of biological origin from the last 5 years. Recent reports in the literature have demonstrated the ability of particles derived from cellulose, lignin, chitin, starch, proteins (soy, zein, ferritin), as well as hydrophobic cells to stabilize biphasic dispersions. We review the use of such nano- and micron-sized particles of biological origin for the stabilization of foams and emulsions, summarize the current knowledge of how such particles stabilize these dispersions, provide an outlook for future work to improve our understanding of bio-derived particle-stabilized foams and emulsions, and touch upon how these systems can be used to create novel materials.

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, Photoélectrochimie. Electrochimiluminescence, Photoelectrochemistry. Electrochemiluminescence, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Sciences appliquees, Applied sciences, Energie, Energy, Energie naturelle, Natural energy, Energie solaire, Solar energy, Conversion photovoltaïque, Photovoltaic conversion, Cellules solaires. Cellules photoélectrochimiques, Solar cells. Photoelectrochemical cells, Composé binaire, Binary compound, Compuesto binario, Composé de métal de transition, Transition element compounds, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Catalyseur, Catalyst, Catalizador, Cellule photoélectrochimique, Photoelectrochemical cell, Célula fotoelectroquímica, Colorant, Dyes, Colorante, Fluorescence, Fluorescencia, Manganèse II, Manganese II, Manganeso II, Nanoparticule, Nanoparticle, Nanopartícula, Oxydation, Oxidation, Oxidación, Oxyde de titane, Titanium oxide, Titanio óxido, Photoélectrochimie, Photoelectrochemistry, Fotoelectroquímica, TiO2, Dye-sensitized photoelectrochemical cell, Photoanode, and Turn-on fluorescence

A manganese complex covalently attached to a TiO2 electrode via a light-absorbing organic linker (L) was used in the photooxidation of 2',7'-dihydrodichlorofluorescein (H2DCF). Significant and sustained photocurrent was observed upon visible-light illumination of the fully assembled anode in the presence of the substrate. The two-electron, two-proton oxidation of H2DCF yields the fluorescent compound, 2',7'-dichlorofluorescein (DCF). Our studies suggest that the MnII-L-TiO2 architecture is an effective photoanode for multielectron chemistry, as production of DCF under visible-light illumination exceeds yields observed for bare TiO2 as well as ZnII-L-TiO2 anodes. The turn-on fluorescent behavior of H2DCF upon oxidation makes it an excellent substrate for the study of new photoanodes. The high fluorescence quantum yield of DCF allows for nanomolar sensitivity and real-time monitoring of substrate oxidation.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Etudes théoriques. Données et constantes. Mesures, Theoretical studies. Data and constants. Metering, Combustion. Flammes, Combustion. Flame, Combustion des combustibles liquides, Combustion of liquid fuels, Biocarburant, Biofuel, Biocarburante, Chaîne courte, Short chain, Cadena corta, Cinétique, Kinetics, Cinética, Combustion, Combustión, Ester, Flamme laminaire, Laminar flame, Llama laminar, Oxydation, Oxidation, Oxidación, Propagation flamme, Flame propagation, Propagación llama, Acide alcanoïque ester méthyle, Acide alcanoïque ester éthyle, Alkyl esters, Ethyl esters, Laminar flames, and Methyl esters

The oxidation characteristics of several small methyl and ethyl esters with carbon number less than six were investigated in laminar flames. The kinetics of such fuels are subsets of those of larger alkyl esters that are constituents of practical biodiesel fuels. A total of seven fuels, namely methyl formate, methyl acetate, methyl propionate, methyl butanoate, ethyl formate, ethyl acetate, and ethyl propionate were considered. Experiments were conducted at atmospheric pressure, elevated reactant temperatures, and over a wide range of equivalence ratios. Laminar flame speeds were determined in the counterflow configuration in which flow velocities were measured using particle image velocimetry. Several detailed kinetic models were tested against the experimental data, and insight was provided into the high-temperature combustion kinetics of the aforementioned fuels. Based on comparisons between experimental and computed results it became apparent that the chemistry of alkyl-ester combustion chemistry is evolving and much needs to be done in order to derive improved rate constants for a wide range of elementary steps.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Chemical engineering, Génie chimique, 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, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Composé de métal de transition, Transition element compounds, Catalyse hétérogène, Heterogeneous catalysis, Catálisis heterogénea, Catalyseur, Catalyst, Catalizador, Electrolyte, Electrólito, Oxyde de titane, Titanium oxide, Titanio óxido, Oxygène, Oxygen, Oxígeno, Pile combustible, Fuel cell, Pila combustión, Polymère, Polymer, Polímero, Protection environnement, Environmental protection, Protección medio ambiente, Réduction chimique, Chemical reduction, Reducción química, Technologie bas carbone, Cathode catalyst, Conductive oxides, Non-Pt catalysts, Oxygen reduction reaction, and Polymer electrolyte fuel cells

Nb-doped TiO2 particles were studied as electrocatalysts for the oxygen reduction reaction (ORR) under acidic conditions. The Nb-doped TiN nanoparticles were first synthesized by meso-porous C3 N4 and then fully oxidized to Nb-doped TiO2 by immersing in 0.1 M H2SO4 at 353 K for 24 h. Although the ORR activity of the as-obtained sample was low, a H2 treatment at relatively high temperature (1173 K) dramatically improved the ORR performance. An onset potential as high as 0.82 VRHE was measured. No degradation of the catalysts was observed during the oxidation-reduction cycles under the ORR condition for over 127 h. H2 treatment at temperatures above 1173 K caused the formation of a Ti4O7 phase, resulting in a decrease in ORR current. Elemental analysis indicated that the Nb-doped TiO2 contained 25 wt% residual carbon. Calcination in air at 673 or 973 K eliminated the residual carbon in the catalyst, which was accompanied by a dramatic decrease in ORR activity. This post-calcination process may reduce the conductivity of the sample by filling the oxygen vacancies, and the carbon residue in the particle aggregates may enhance the electrocatalytic activity for ORR. The feasibility of using conductive oxide materials as electrocatalysts is discussed.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, 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, Interface gaz-liquide et liquide-liquide, Gas-liquid interface and liquid-liquid interface, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Cellulose et dérivés, Cellulose and derivatives, Article synthèse, Review, Artículo síntesis, Autoassemblage, Self assembly, Autoensamble, Cellulose, Celulosa, Colloïde, Colloid, Coloide, Interface gaz liquide, Gas liquid interface, Interfase gas líquido, Interface liquide liquide, Liquid liquid interface, Interfase líquido líquido, Interface, Interfase, Nanocristal, Nanocrystal, Nanoparticule, Nanoparticle, Nanopartícula, Particule, Particle, Partícula, Anisotropic particles, Cellulose nanocrystals, Cellulose nanofibrils, Nanocellulose, Nanoparticles, and Self-assembly

In this review we introduce recent advances in the development of cellulose nanomaterials and the construction of high order structures by applying some principles of colloid and interface science. These efforts take advantage of natural assemblies in the form of fibers that nature constructs by a biogenetic bottom-up process that results in hierarchical systems encompassing a wide range of characteristic sizes. Following the reverse process, a top-down deconstruction, cellulose materials can be cleaved from fiber cell walls. The resulting nanocelluloses, mainly cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC, i.e., defect-free, rod-like crystalline residues after acid hydrolysis of fibers), have been the subject of recent interest. This originates from the appealing intrinsic properties of nanocelluloses: nanoscale dimensions, high surface area, morphology, low density, chirality and thermo-mechanical performance. Directing their assembly into multiphase structures is a quest that can yield useful outcomes in many revolutionary applications. As such, we discuss the use of non-specific forces to create thin films of nanocellulose at the air-solid interface for applications in nano-coatings, sensors, etc. Assemblies at the liquid―liquid and air―liquid interfaces will be highlighted as means to produce Pickering emulsions, foams and aerogels. Finally, the prospects of a wide range of hybrid materials and other systems that can be manufactured via self and directed assembly will be introduced in light of the unique properties of nanocelluloses.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, 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, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Lignine et dérivés, Lignin and derivatives, Agrégation, Aggregation, Agregación, Application, Aplicación, Article synthèse, Review, Artículo síntesis, Biomasse, Biomass, Biomasa, Chimie surface, Surface chemistry, Fibre carbone, Carbon fiber, Fibra carbón, Lignine, Lignin, Lignina, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Stabilité, Stability, Estabilidad, Carbon fibers, Colloidal stability, Lignin surface chemistry, and Self-aggregation

In this paper, we focus on the recent advances on the physical chemistry of lignin. Emerging trends of incorporating lignin in promising future applications such as controlled release, saccharification of lignocelluloses, bioplastics, composites, nanoparticles, adsorbents and dispersants, in electro-chemical applications and carbon fibers, are also reviewed. We briefly describe the complexity of the lignin structure that influences the solution behavior, both as a macromolecule and a colloid, as well as the potential of being a renewable precursor in the development of high-value applications. Special attention is paid on summarizing the present knowledge on lignin colloidal stability and surface chemistry.