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Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, Sciences exactes et technologie, Exact sciences and technology, Terre, ocean, espace, Earth, ocean, space, Geophysique externe, External geophysics, Météorologie, Meteorology, Climatologie. Bioclimatologie. Changement climatique, Climatology. Bioclimatology. Climate change, Composé organique, organic compounds, Adsorbant, Adsorbent, Adsorbente, Adsorption gaz solide, Gas solid adsorption, Adsorción gas sólido, Amine, Amina, Biopolymère, Biopolymer, Biopolímero, Cellulose, cellulose, Celulosa, Changement climatique, climate change, Dioxyde de carbone, Carbon dioxide, Carbono dióxido, Développement durable, sustainable development, Gaz effet serre, greenhouse gas, Matériau modifié, Modified material, Material modificado, Mitigation, Nanofibre, Nanofiber, Nanofibra, Nanomatériau, Nanostructured materials, Nanotechnologie, Nanotechnology, Nanotecnología, Séquestration CO2, CO2 sequestration, Secuestración CO2, Séquestration carbone, Carbon sequestration, Secuestro carbono, Traitement surface, Surface treatment, and Tratamiento superficie

A fundamental analysis of single-component and binary CO2 and H2O adsorption of amine-functionalized nanofibrillated cellulose is carried out in the temperature range of 283―353 K and at CO2 partial pressures in the range of 0.02―105 kPa, where the ultralow partial pressure range is relevant for the direct capture of CO2 from atmospheric air. Single-component CO2 and H2O adsorption experimental data are fitted to the Toth and Guggenheim―Anderson―de Boer models, respectively. Corresponding heats of adsorption, derived from explicit solutions of the van't Hoff equation, are ―50 kJ/mol CO2 and ―48.8 kJ/mol H2O. Binary CO2/H2O adsorption measurements for humid air reveal that the presence of H2O at 2.55 kPa enhances CO2 adsorption, while the presence of CO2 at 0.045 kPa does not influence H2O adsorption. The energy demand of the temperature-vacuum-swing adsorption/desorption cycle for delivering pure CO2 from air increases significantly with H2O adsorption and indicates the need to reduce the hygroscopicity of the adsorbent.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Surfaces et interfaces; couches minces et trichites (structure et propriétés non électroniques), Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties), Structures de basse dimensionnalité (superréseaux, puits quantiques, multicouches): structure et propriétés non électroniques, Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Méthodes de nanofabrication, Methods of nanofabrication, Formation de nanomotifs, Nanoscale pattern formation, 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, Charge superficielle, Surface charge, Carga superficial, Confinement, Confinamiento, Courant ionique, Ionic current, Corriente iónica, Densité charge, Charge density, Densidad carga, Diode, Diodo, Dispositif nanofluidique, Nanofluidic device, Dispositivo nanofluidic, Dépendance du temps, Time dependence, Dependencia del tiempo, Dépôt phase vapeur, Vapor deposition, Depósito fase vapor, Effet pH, pH effect, Efecto pH, Force ionique, Ionic strength, Fuerza iónica, Formation motif, Patterning, Formacíon motivo, Macromolécule, Macromolecule, Macromolécula, Marqueur biologique, Biological marker, Marcador biológico, Nanopore, Nanoporo, Nanoporosité, Nanoporosity, Nanoporosidad, Protéine, Protein, Proteína, Réseau (arrangement), Array, Red, Réseau diode, Diode array, Red diodo, Silicium, Silicon, Silicio, Simulation numérique, Numerical simulation, Simulación numérica, Traitement surface, Surface treatment, Tratamiento superficie, Transistor nanofluidique, Nanofluidic transistor, Transistor nanofluídico, Verre, Glass, Vidrio, pH, and 8116R

We demonstrate here for the first time the utility of an integrated nanofluidic diode for detecting and quantifying physiologically relevant macromolecules. Troponin T, a key human cardiac protein biomarker, was selectively and rapidly detected free of labels for concentrations down to 10 fg/mL (~0.3 M) in buffer as well as 10 pg/mL (~300 fM) in untreated human serum. This ultrasensitive detection arises from monolithic integration of a unique nanofluidic diode structure that is highly robust and amenable to site-specific surface modification. The structure features a planar nanoslit array where each nanoslit is defined at a nominal width of 70 nm over a micrometer-scale silicon trench without the use of high-resolution patterning techniques. Through vapor deposition, a glass layer is placed at a nonuniform thickness, tapering the trench profile upward and contributing to the triangular nanoslit structure. This asymmetric profile is essential for ionic current rectification noted here at various pH values, ionic strengths, and captured target species, which modulate the surface-charge density within the sensitive region of the nanoslit The nanoslit, unlike nanopores, offers only 1D confinement, which appears to be adequate for reasonable rectification. The measurements are found in quantitative agreement with the diode simulations for the first time based on a pH- and salt-dependent surface-charge model.

Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biophysique moleculaire, Molecular biophysics, Chimie physique en biologie, Physical chemistry in biology, Electrochimie, Electrochemistry, Acier inoxydable, Stainless steel, Acero inoxidable, Biocompatibilité, Biocompatibility, Biocompatibilidad, Biofilm, Bioélectrochimie, Bioelectrochemistry, Bioelectroquímica, Caractérisation, Characterization, Caracterización, Densité courant, Current density, Densidad corriente, Electrocatalyse, Electrocatalysis, Electrocatálisis, Fer Oxyde, Iron Oxides, Hierro Óxido, Formation, Formación, Matériau électrode, Electrode material, Material electrodo, Microscopie force atomique, Atomic force microscopy, Microscopía fuerza atómica, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Morphologie, Morphology, Morfología, Nanoparticule, Nanoparticle, Nanopartícula, Oxydation, Oxidation, Oxidación, Rayon X, X ray, Rayos X, Spectrométrie photoélectron, Photoelectron spectrometry, Espectrometría fotoelectrón, Structure surface, Surface structure, Estructura superficie, Traitement surface, Surface treatment, and Tratamiento superficie

Stainless steel (SS) can be an attractive material to create large electrodes for microbial bioelectrochemical systems (BESs), due to its low cost and high conductivity. However, poor biocompatibility limits its successful application today. Here we report a simple and effective method to make SS electrodes biocompatible by means of flame oxidation. Physicochemical characterization of electrode surface indicated that iron oxide nanoparticles (IONPs) were generated in situ on an SS felt surface by flame oxidation. IONPs-coating dramatically enhanced the biocompatibility of SS felt and consequently resulted in a robust electroactive biofilm formation at its surface in BESs. The maximum current densities reached at IONPs-coated SS felt electrodes were 16.5 times and 4.8 times higher than the untreated SS felts and carbon felts, respectively. Furthermore, the maximum current density achieved with the IONPs-coated SS felt (1.92 mA/cm2, 27.42 mA/cm3) is one of the highest current densities reported thus far. These results demonstrate for the first time that flame oxidized SS felts could be a good alternative to carbon-based electrodes for achieving high current densities in BESs. Most importantly, high conductivity, excellent mechanical strength, strong chemical stability, large specific surface area, and comparatively low cost of flame oxidized SS felts offer exciting opportunities for scaling-up of the anodes for BESs.

Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Pollution, Traitement et pollution des eaux, Water treatment and pollution, Eaux usées, Wastewaters, Eaux usées industrielles, Industrial wastewaters, Dispositif semiconducteur, Semiconductor device, Dispositivo semiconductor, Eau usée industrielle, Industrial waste water, Agua servida industrial, Fabrication microélectronique, Microelectronic fabrication, Fabricación microeléctrica, Industrie électronique, Electronics industry, Industria electrónica, Lanthanide Composé, Lanthanide Compounds, Lantánido Compuesto, Mesure concentration, Concentration measurement, Medición concentración, Nanomatériau, Nanostructured materials, Nanoparticule, Nanoparticle, Nanopartícula, Nanotechnologie, Nanotechnology, Nanotecnología, Oxyde de cérium, Cerium oxide, Cerio óxido, Polissage mécanochimique, Chemical mechanical polishing, Traitement surface, Surface treatment, and Tratamiento superficie

This work measured and compared the effluent from the chemical mechanical polishing (CMP) of silicon dioxide using ceria slurry and ceria fixed abrasive. CMP waste streams were tested for total solids, cerium, silicon, and 6 nm to 20 μm diameter particles. The concentration of cerium and total solids in the effluent were very different for the two polishes studied. The fixed abrasive polish produced 94% less CeO2 emissions per SiO2 removed. The higher ceria levels in the slurry effluent are associated with 99―279 nm particles, and attributed to ceria abrasive. The lower concentration of ceria in the effluent from the fixed abrasive process is due to the lower wear rate of mineral from the fixed abrasive, compared to the more environmentally mobile mineral in the slurry. These results support the bonded nature of the abrasive particles in fixed abrasive polishing and are relevant to sustainability strategies that seek to reduce particle emissions in surface conditioning technology.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, 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, Interface solide-liquide, Solid-liquid interface, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Amine, Amina, Angle contact, Contact angle, Angulo contacto, Anodisation, Anodizing, Anodización, Composé organique, Organic compounds, Compuesto orgánico, Liaison chimique, Chemical bond, Enlace químico, Matériau poreux, Porous material, Material poroso, Microscopie électronique balayage, Scanning electron microscopy, Microscopía electrónica barrido, Morphologie surface, Surface morphology, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Nanotube, Nanotubo, Spectre photoélectron RX, X-ray photoelectron spectra, Titane, Titanium, Titanio, Traitement chimique, Chemical treatment, Tratamiento químico, Traitement surface, Surface treatment, Tratamiento superficie, Traitement thermique, Heat treatment, Tratamiento térmico, and Ti

The influence of acid―base properties of titanium (T35) on the adsorption of model amine molecules as a function of surface treatments, necessary for modification of surface morphology and its chemical composition, has been investigated by X-ray photoelectron spectroscopy. A significant increase in the surface energy measured by contact-angle measurements has been observed after surface treatment (thermal, chemical treatment in alkali electrolyte, and electrochemical treatment: anodization) compared with the pristine sample (+75% on average). An important modification of surface morphology was observed by scanning electron microscopy ) after the electrochemical (anodization) and chemical treatment of Ti resulting in formation of TiO2 nanotubes and porous TiO2 surface, respectively. Two amine molecules have been chosen to study the adsorption in a function of Ti surface treatment: propylamine (PPA) and 1,2-diaminoethane (DAE). The increased intensities of N1s and C1s core level peaks indicate a stronger adsorption of DAE than PPA molecule on all type of titanium surfaces. The layer thickness of amines ranged between 0.6 and 0.8 nm and 0.9 and 1.5 nm for PPA and DAE molecule, respectively. It has been shown that higher hydroxyl fraction results in the formation of thicker amine layer. The surface hydroxylation also had an influence on the Brønsted/Lewis distribution. A higher Brønsted interaction was observed with higher surface hydroxylation. For both amines and for all treated surfaces, adsorption occurred in majority via a Lewis-like interaction.

Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie analytique, Analytical chemistry, Méthodes spectrométriques et optiques, Spectrometric and optical methods, Sciences appliquees, Applied sciences, Pollution, Traitement et pollution des eaux, Water treatment and pollution, Pollution des eaux naturelles, Natural water pollution, Méthodes d'analyse, Analysis methods, Elément trace, Trace element, Elemento traza, Métal lourd, Heavy metal, Metal pesado, DNA, Energie résonance, Resonance energy, Energía resonancia, Fluorescence, Fluorescencia, Mercure II, Mercury II, Mercurio II, Mesure concentration, Concentration measurement, Medición concentración, Méthode mesure, Measurement method, Método medida, Nanocristal, Nanocrystal, Nanomatériau, Nanostructured materials, Nanoparticule, Nanoparticle, Nanopartícula, Or, Gold, Oro, Point quantique, Quantum dot, Punto cuántico, Pollution eau, Water pollution, Contaminación agua, Porte temporelle, Time gate, Puerta temporal, Semiconducteur, Semiconductor materials, Semiconductor(material), Sensibilité, Sensitivity, Sensibilidad, Technique rapide, Rapid technique, Técnica rápida, Traitement surface, Surface treatment, and Tratamiento superficie

The authors herein described a time-gated fluorescence resonance energy transfer (TGFRET) sensing strategy employing water-soluble long lifetime fluorescence quantum dots and gold nanoparticles to detect trace Hg2+ ions in aqueous solution. The water-soluble long lifetime fluorescence quantum dots and gold nanoparticles were functionalized by two complementary ssDNA, except for four deliberately designed T― T mismatches. The quantum dot acted as the energy-transfer donor, and the gold nanoparticle acted as the energy-transfer acceptor. When Hg2+ ions were present in the aqueous solution, DNA hybridization will occur because of the formation of T― Hg2+―T complexes. As a result, the quantum dots and gold nanoparticles are brought into close proximity, which made the energy transfer occur from quantum dots to gold nanoparticles, leading to the fluorescence intensity of quantum dots to decrease obviously. The decrement fluorescence intensity is proportional to the concentration of Hg2+ ions. Under the optimum conditions, the sensing system exhibits the same liner range from 1 × 10―9 to 1 X 10―8 M for Hg2+ ions, with the detection limits of 0.49 nM in buffer and 0.87 nM in tap water samples. This sensor was also used to detect Hg2+ ions from samples of tap water, river water, and lake water spiked with Hg2+ ions, and the results showed good agreement with the found values determined by an atomic fluorescence spectrometer. In comparison to some reported colorimetric and fluorescent sensors, the proposed method displays the advantage of higher sensitivity. The TGFRET sensor also exhibits excellent selectivity and can provide promising potential for Hg2+ ion detection.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, 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, Matériaux particuliers, Specific materials, Fullerènes et matériaux apparentés; diamants, graphite, Fullerenes and related materials; diamonds, graphite, Nanomatériaux et nanostructures : fabrication et caractèrisation, Nanoscale materials and structures: fabrication and characterization, Fils quantiques, Quantum wires, 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, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Bande conduction, Conduction band, Banda conducción, Leitungsband, Cellule solaire, Solar cell, Célula solar, Epaisseur couche, Layer thickness, Espesor capa, Schichtdicke, Graphène, Graphene, Hétérojonction, Heterojunction, Heterounión, Nanofil, Nanowires, Nanomatériau, Nanostructured materials, Nanostructure, Nanoestructura, Optimisation, Optimization, Optimización, Optimierung, Orbitale moléculaire, Molecular orbital, Orbital molecular, Réseau (arrangement), Array, Red, Silicium, Silicon, Silicio, Spectre absorption, Absorption spectrum, Espectro de absorción, Technique basse température, Low-temperature techniques, Thiophène dérivé polymère, Thiophene derivative polymer, Tiofeno derivado polímero, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Travail sortie, Work function, Función de trabajo, Austrittsarbeit, 8105U, 8107V, 8460J, Substrat graphène, and Substrat silicium

In comparison to conventional metallic electrodes, graphene possesses superior properties in terms of higher optical transmittance, tunable work function, excellent stability in air, etc. Here, we demonstrate the use of graphene as transparent conductive electrodes for constructing highly efficient hybrid heterojunction solar cells based on nanostructured silicon, including silicon nanowire (SiNW) and silicon nanohole (SiNH) arrays. Poly(3-hexylthiophene) (P3HT) is adopted as hole transport layer in the hybrid heterojunction. It also offers a large offset between lowest unoccupied molecular orbital of the organic and the conduction band minimum of Si to reduce the electron recombination at graphene anode. The roles of graphene layer number, silicon surface modification, as well as P3HT layer thickness are systemically investigated. After sufficient device optimization, the devices based on graphene/P3HT/SiNW array and graphene/P3HT/SiNH array have achieved power conversion efficiencies of 9.94% and 10.34%, respectively. Considering the simple and low-cost solution processed capability for both graphene and P3HT layers, we believed that graphene/organic/silicon is a viable low-temperature technique for highly efficient silicon solar cell.

General chemistry, physical chemistry, Chimie générale, chimie physique, Biomedical engineering, Génie biomédical, Materials, Matériaux, Condensed state physics, Physique de l'état condensé, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biophysique moleculaire, Molecular biophysics, Adsorption, Adsorción, Couche ultramince, Ultrathin films, Cytochrome c, Citocromo c, Effet tunnel, Tunnel effect, Efecto túnel, Microbalance quartz, Quartz microbalance, Microbalanza cuarzo, Modification chimique, Chemical modification, Modificación química, Or, Gold, Oro, Propriété électrochimique, Electrochemical properties, Propiedad electroquímica, Résonance plasmon surface, Surface plasmon resonance, Traitement surface, Surface treatment, Tratamiento superficie, Transfert électron, Electron transfer, and Transferencia electrón

Quartz crystal microbalance (QCM), surface plasmon resonance (SPR), and electrochemistry techniques were used to study the electron-transfer (ET) reaction of cytochrome c (Cyt c) on gold surfaces modified with thionicotinamide, thioisonicotinamide, 4-mercaptopyridine, 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol, 5-phenyl-1,3,4-oxadiazole-2-thiol, 4,4'-bipyridine, and 4,4'-dithiopyridine. The electrochemical results showed that the ET process is complex, being chiefly diffusional with steps depending on the orientation of the pyridine or phenyl tail group of the modifiers. The correlation between the electrochemical results and those acquired by SPR and QCM indicated the presence of an adlayer of Cyt c adsorbed on the thiolate SAMs. This adlayer, although being not electroactive, is essential to assess the ET reaction of Cyt c in solution. The results presented in this work are consistent with the statement (Feng, Z. Q.; Imabayashi, S.; Kakiuchi, T.; Niki, K. J. Electroanal. Chem. 1995, 394, 149―154) that the ET reaction of Cyt c can be explained in terms of the through-bond tunneling mechanism.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, 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, Cellule solaire à colorant, Dye-sensitized solar cell, Célula solar sensibilizada tinte, Colorant organique, Organic dye, Colorante orgánico, Courant court circuit, Short circuit currents, Densité électron, Electron density, Densidad electrón, Epitaxie jet chimique, Chemical beam epitaxy, Optimisation, Optimization, Optimización, Oxyde de zinc, Zinc oxide, Zinc óxido, Rendement, Yield, Rendimiento, Semiconducteur, Semiconductor materials, Semiconductor(material), Solution aqueuse, Aqueous solution, Solución acuosa, Traitement surface, Surface treatment, Tratamiento superficie, 8105R, and ZnO

ZnO is a promising candidate as a low-cost porous semiconductor material for photoelectrodes in dye-sensitized solar cells (DSSCs). However, ZnO-based DSSCs tend to exhibit lower energy conversion efficiencies than do those based on TiO2. In this study, the performance of ZnO porous electrodes was enhanced using a surface treatment carried out by immersion in cold aqueous TiCl4 solution that resulted in TiO2-coated ZnO (Z/T) electrodes. The Z/T electrodes were sensitized with either the Ru complex dye N719 or the organic indoline dye D149. For each dye, the DSSCs with the Z/T photoelectrodes showed the highest open-circuit voltage (Voc), short circuit current (Jsc), and power conversion efficiency compared to those with ZnO, TiO2, or TiO2-coated TiO2 (T/T) electrodes. To study the effects of the TiCl4 treatment, the relationships between the electron lifetime (r), cell voltage, and electron density (n) of the cells prepared with each electrode, with each of the two dyes, or without either dye were assessed. It was found that the TiCl4 treatment negatively shifted the conduction band edge (CBE) potential of the ZnO electrodes by more than 100 mV for both dyes and also in the absence of a dye. In addition, τ increased with the use of the organic D149 and in the absence of a dye. The DSSC with a D149-sensitized Z/T layer showed the highest efficiency of 4.89% under 100 mW cm-2 irradiation.

Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Pollution, Traitement et pollution des eaux, Water treatment and pollution, Pollution des eaux naturelles, Natural water pollution, Phénomènes biologiques et physicochimiques, Biological and physicochemical phenomena, Pollution du sol et des sédiments, Soil and sediments pollution, Propriétés biologiques et physicochimiques des polluants. Interaction dans le sol, Biological and physicochemical properties of pollutants. Interaction in the soil, Terre, ocean, espace, Earth, ocean, space, Sciences de la terre, Earth sciences, Géologie de l'ingénieur et de l'environnement. Géothermie, Engineering and environment geology. Geothermics, Pollution, géologie de l'environnement, Pollution, environment geology, Devenir polluant, Pollutant behavior, Evolución contaminante, Hydrochimie, Hydrochemistry, Hidroquímica, Impact environnement, Environment impact, Impacto medio ambiente, Latex, Látex, Matière organique, Organic matter, Materia orgánica, Matériau modifié, Modified material, Material modificado, Nanocristal, Nanocrystal, Nanomatériau, Nanostructured materials, Nanoparticule, Nanoparticle, Nanopartícula, Nanotechnologie, Nanotechnology, Nanotecnología, Phénomène transport, Transport process, Fenómeno transporte, Point quantique, Quantum dot, Punto cuántico, Pollution eau, Water pollution, Contaminación agua, Pollution sol, Soil pollution, Polución suelo, Revêtement, Coatings, Revestimiento, Semiconducteur, Semiconductor materials, Semiconductor(material), Styrène polymère, Styrene polymer, Estireno polímero, Sédiment, Sediments, Sedimento, Séléniure de cadmium, Cadmium selenides, Tellurure de cadmium, Cadmium tellurides, Traitement surface, Surface treatment, and Tratamiento superficie

A clear understanding of the factors controlling the deposition behavior of engineered nanoparticles (ENPs), such as quantum dots (QDs), is necessary for predicting their transport and fate in natural subsurface environments and in water filtration processes. A quartz crystal microbalance with dissipation monitoring (QCM-D) was used to study the effect of particle surface coatings and water chemistry on the deposition of commercial QDs onto Al2O3. Two carboxylated QDs (CdSe and CdTe) with different surface coatings were compared with two model nanoparticles: sulfate-functionalized (sPL) and carboxyl-modified (cPL) polystyrene latex. Deposition rates were assessed over a range of ionic strengths (IS) in simple electrolyte (KCl) and in electrolyte supplemented with two organic molecules found in natural waters; namely, humic acid and rhamnolipid. The Al2O3 collector used here is selected to be representative of oxide patches found on the surface of aquifer or filter grains. Deposition studies showed that ENP deposition rates on bare Al2O3 generally decreased with increasing salt concentration, with the exception of the polyacrylic-acid (PAA) coated CdTe QD which exhibited unique deposition behavior due to changes in the conformation of the PAA coating. QD deposition rates on bare Al2O3 were approximately 1 order of magnitude lower than those of the polystyrene latex nanoparticles, likely as a result of steric stabilization imparted by the QD surface coatings. Adsorption of humic acid or rhamnolipid on the Al2O3 surface resulted in charge reversal of the collector and subsequent reduction in the deposition rates of all ENPs. Moreover, the ratio of the two QCM-D output parameters, frequency and dissipation, revealed key structural information of the ENP-collector interface; namely, on bare Al2O3, the latex particles were rigidly attached as compared to the more loosely attached QDs. This study emphasizes the importance of considering the nature of ENP coatings as well as organic molecule adsorption onto particle and collector surfaces to avoid underestimating ENP mobility in natural and engineered aquatic environments.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Propriété biologique, Biological properties, Propiedad biológica, Propriété surface, Surface properties, Propiedad superficie, Adhérence cellulaire, Cell adhesion, Adherencia celular, Antibactérien, Antibacterial agent, Antibacteriano, Argent, Silver, Plata, Bactéricidie, Bactericidal effect, Bactericidia, Etude expérimentale, Experimental study, Estudio experimental, Glycolique acide copolymère, Glycolic acid copolymer, Glicolico acido copolimero, In vitro, Lactique acide copolymère, Lactic acid copolymer, Láctico ácido copolímero, Mouillabilité, Wettability, Remojabilidad, Nanocomposite, Nanocompuesto, Particule métallique, Metal particle, Partícula metálica, Topographie surface, Surface topography, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, and Tratamiento superficie

The purpose of this study is to investigate the combined effects of oxygen plasma treatments and silver nanoparticles (Ag) on PLGA in order to modulate the surface antimicrobial properties through tunable bacteria adhesion mechanisms. PLGA nanocomposite films, produced by solvent casting with 1 wt % and 7 wt % of Ag nanoparticles were investigated. The PLGA and PLGA/Ag nanocomposite surfaces were treated with oxygen plasma. Surface properties of PLGA were investigated by field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), static contact angle (CA), and high resolution X-ray photoelectron spectroscopy (XPS). Antibacterial tests were performed using an Escherichia coli RB (a Gram negative) and Staphylococcus aureus 8325-4 (a Gram positive). The PLGA surface becomes hydrophilic after the oxygen treatment and its roughness increases with the treatment time. The surface treatment and the Ag nanoparticle introduction have a dominant influence on the bacteria adhesion and growth. Oxygen-treated PLGA/Ag systems promote higher reduction of the bacteria viability in comparison to the untreated samples and neat PLGA. The combination of Ag nanoparticles with the oxygen plasma treatment opens new perspective for the studied biodegradable systems in biomedical applications.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés de surface, Surface properties, Adsorption, Adsorción, Carboxylate polymère, Carboxylate polymer, Carboxilato polímero, Couche superficielle, Surface layer, Capa superficial, Liaison chimique, Chemical bond, Enlace químico, Propriété interface, Interface properties, Propiedad interfase, Spectrométrie FTIR, Fourier-transformed infrared spectrometry, Espectrometría FTIR, Structure moléculaire, Molecular structure, Estructura molecular, Traitement surface, Surface treatment, Tratamiento superficie, Zinc, and Zn

The interfacial bonding properties of carboxylic polymers on a Zn substrate have been investigated. Poly(methyl vinyl ether-alt-maleic acid monobutyl ester) and cured propoxylated bisphenol A fumarate unsaturated polyester were applied on a set of differently treated Zn samples. The buried metal-polymer interface was studied by polymer removal and evaluation of the residue layers on Zn surfaces representing the metal-polymer interface region. Additionally, the interfacial bondings were mimicked by adsorption of the representative carboxylic monomers, i.e., succinic and myristic acids. The differently treated Zn surfaces were found to be capable of adsorption of the carboxyl functionality of the polymers, resulting in formation of carboxylates. A comparison of the interfacial bondings by the residue layers of the polymers with those formed due to the molecular adsorption showed comparable adsorption mechanisms. Additionally, it was found that the polymer-metal interfacial bonding density mainly depends on the Zn surface hydroxyl fraction, while Zn oxide semiconductor properties play an important role when a curing process occurs during the polymer interaction with Zn surfaces.

Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, 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, Pollution, Traitement et pollution des eaux, Water treatment and pollution, Eaux potables, eaux de piscine, dessalement, Drinking water and swimming-pool water. Desalination, Eaux usées, Wastewaters, Procédés généraux d'épuration, General purification processes, Elément trace, Trace element, Elemento traza, Métal lourd, Heavy metal, Metal pesado, Adsorbant, Adsorbent, Adsorbente, Adsorption liquide solide, Liquid solid adsorption, Adsorción líquido sólido, Matériau modifié, Modified material, Material modificado, Matériau poreux, Porous material, Material poroso, Mutagène, Mutagen, Mutágeno, Nanocomposite, Nanocompuesto, Nanomatériau, Nanostructured materials, Nanoparticule, Nanoparticle, Nanopartícula, Oxyde de zirconium, Zirconium oxide, Zirconio óxido, Plomb, Lead, Plomo, Styrène polymère, Styrene polymer, Estireno polímero, Sulfonate, Sulfonato, Traitement eau, Water treatment, Tratamiento agua, Traitement surface, Surface treatment, and Tratamiento superficie

A novel hybrid nanomaterial was fabricated by encapsulating ZrO2 nanoparticles into spherical polystyrene beads (MPS) covalently bound with charged sulfonate groups (-SO3-). The resultant adsorbent, Zr-MPS, exhibited more preferential sorption toward Pb(II) than the simple equivalent mixture of MPS and ZrO2. Such observation might be ascribed to the presence of sulfonate groups of the polymeric host, which could enhance nano-ZrO2 dispersion and Pb(II) diffusion kinetics. To further elucidate the role of surface functional groups, we encapsulated nano-ZrO2 onto another two macroporous polystyrene with different surface groups (i.e., -N(CH3)3+/-CH2Cl, respectively) and a conventional activated carbon. The three obtained nanocomposites were denoted as Zr-MPN, Zr-MPC, and Zr-GAC. The presence of -SO3- and -N(CH3)3+ was more favorable for nano-ZrO2 dispersion than the neutral -CH2Cl, resulting in the sequence of sorption capacities as Zr-MPS > Zr-MPN > Zr-GAC > Zr-MPC. Column Pb(II) sorption by the four nanocomposites further demonstrated the excellent Pb(II) retention by Zr-MPS. Comparatively, Zr-MPN of well-dispersed nano-ZrO2 and high sorption capacities showed much faster breakthrough for Pb(II) sequestration than Zr-MPS, because the electrostatic repulsion of surface quaternary ammonium group of MPN and Pb(II) ion would result in a poor sorption kinetics. This study suggests that charged groups in the host resins improve the dispersion of embedded nanoparticles and enhance the reactivity and capacity for sorption of metal ions. Suitably charged functional groups in the hosts are crucial in the fabrication of efficient nanocomposites for the decontamination of water from toxic metals and other charged pollutants.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, 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, Points quantiques, Quantum dots, Divers, Other topics in nanoscale materials and structures, 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, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Adsorption, Adsorción, Bande valence, Valence band, Banda valencia, Valenzband, Cellule solaire, Solar cell, Célula solar, Couche mince, Thin film, Capa fina, Duennschicht, Electrolyte, Electrólito, Elektrolyt, Etat excité, Excited state, Estado excitado, Facteur limitant, Limiting factor, Factor limitante, Implémentation, Implementation, Implementación, Injection porteur charge, Charge carrier injection, Inyección portador carga, Interface, Interfase, Grenzflaeche, Luminescence, Luminiscencia, Lumineszenz, Mécanisme croissance, Growth mechanism, Mecanismo crecimiento, Wachstumsmechanismus, Nanomatériau, Nanostructured materials, Nickel, Niquel, Photocathode, Fotocátodo, Point quantique, Quantum dot, Punto cuántico, Semiconducteur, Semiconductor materials, Semiconductor(material), Halbleiter, Structure électronique, Electronic structure, Estructura electrónica, Elektronenstruktur, Séléniure de cadmium, Cadmium selenides, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, 8107T, 8110A, 8460J, Al2O3, CdSe, and NiO

Quantum dot sensitized solar cells (QDSCs) are receiving a lot of attention as promising third generation solar cells, being virtually all of them based on sensitized photoanodes. Finding efficient QD-sensitized photocathodes would pave the way toward the implementation of tandem QDSCs. In this context, NiO photocathodes have been sensitized with colloidal CdSe quantum dots directly attached to the semiconductor oxide surface. The emission spectra indicate effective hole injection from the excited state of the quantum dots to the valence band of the NiO. A maximum incident current to photon conversion efficiency of 17% at 420 nm has been achieved. For the sake of comparison, other ways to prepare and anchor the QDs have been tested. Sensitization routes based on presynthesized colloidal quantum dots show better results than in situ growth techniques such as successive ionic layer adsorption and reaction. Electrochemical impedance measurements have identified transport resistance in NiO as one of the limiting factors in the performance of the system under study. Interestingly, surface treatments based on the deposition of very thin films of either SiO2 or Al2O3 can diminish recombination at the NiO/CdSe/electrolyte interface. This work also identifies a number of possible routes for the improvement of this kind of electrodes, unveiling their potential use in tandem quantum dot solar cells.

Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, 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, Membranes, Sciences appliquees, Applied sciences, Genie chimique, Chemical engineering, Séparation par membrane (osmose inverse, dialyse...), Membrane separation (reverse osmosis, dialysis...), Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Résines échangeuses et membranes, Exchange resins and membranes, Pollution, Traitement et pollution des eaux, Water treatment and pollution, Généralités, General, Amide polymère, Nylon, Amida polímero, Encrassement, Fouling, Enmugrecimiento, Ethylène oxyde polymère, Ethylene oxide polymer, Etileno óxido polímero, Matériau composite, Composite material, Material compuesto, Matériau modifié, Modified material, Material modificado, Membrane polymère, Polymeric membrane, Membrana polímero, Osmose, Osmosis, Séparation par membrane, Membrane separation, Separación por membrana, Traitement surface, Surface treatment, Tratamiento superficie, and Membrane anti-encrassement

Forward osmosis (FO) is an emerging membrane-based water separation process with potential applications in a host of environmental and industrial processes. Nevertheless, membrane fouling remains a technical obstacle affecting this technology, increasing operating costs and decreasing membrane life. This work presents the first fabrication of an antifouling thin-film composite (TFC) FO membrane by an in situ technique without postfabrication treatment. The membrane was fabricated and modified in situ, grafting Jeffamine, an amine-terminated poly(ethylene glycol) derivative, to dangling acyl chloride surface groups on the nascent polyamide active layer. Surface characterization by contact angle, Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), zeta potential, atomic force microscopy (AFM), and fluorescence microscopy, confirms the presence of Jeffamine on the membrane surface. We demonstrate the improved fouling resistance of the in situ modified membranes through accelerated dynamic fouling FO experiments using a synthetic wastewater feed solution at high concentration (250 mg/L) of alginate, a model macromolecule for the hydrophilic fraction of wastewater effluent organic matter. Our results show a significantly lower flux decline for the in situ modified membranes compared to pristine polyamide (14.3 ± 2.7% vs 2.8 ± 1.4%, respectively). AFM adhesion force measurements between the membrane and a carboxylate-modified latex particle, a surrogate for the organic (alginate) foulant, show weaker foulant― membrane interactions, further confirming the enhanced fouling resistance of the in situ modified membranes.

General chemistry, physical chemistry, Chimie générale, chimie physique, Biomedical engineering, Génie biomédical, Materials, Matériaux, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, 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, Chromatophore, Cromatóforo, Conversion énergie, Energy conversion, Conversión energética, Fluorescence, Fluorescencia, Microstructure, Microestructura, Propriété électrochimique, Electrochemical properties, Propiedad electroquímica, Rayonnement solaire, Solar radiation, Radiación solar, Source lumière, Light sources, Traitement surface, Surface treatment, and Tratamiento superficie

Owing to the considerable current interest in replacing fossil fuels with solar radiation as a clean, renewable, and secure energy source, light-driven electron transport in natural photosynthetic systems offers a valuable blueprint for conversion of sunlight to useful energy forms. In particular, intracytoplasmic membrane vesicles (chromatophores) from the purple bacterium Rhodospirillum rubrum provide a fully functional and robust photosynthetic apparatus, ideal for biophysical investigations of energy transduction and incorporation into biohybrid photoelectrochemical devices. These vesicular organelles, which arise by invagination of the cytoplasmic membrane, are the sites of the photochemical reaction centers and the light harvesting 1 (LH1) complex. The LH1 protein is responsible for collecting visible and near-IR radiant energy and funneling these excitations to the reaction center for conversion into a transmembrane charge separation. Here, we have investigated the morphology, fluorescence kinetics and photocurrent generation of chromatophores from Rsp. rubrum deposited directly onto gold surfaces in the absence of chemical surface modifications. Atomic force microscopy showed a significant coverage of the gold electrode surface by Rsp. rubrum chromatophores. By in situ fluorescence induction/relaxation measurements, a high retention of the quantum yield of photochemistry was demonstrated in the photoactive films. Chronoamperometric measurements showed that the assembled bioelectrodes were capable of generating sustained photocurrent under white light illumination at 220 mW/cm2 with a maximum current of 1.5 μA/cm2, which slowly declines in about 1 week. This study demonstrates the possibility of photoelectrochemical control of robust chromatophore preparations from Rsp. rubrum that paves the way for future incorporation into functional solar cells.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Surfaces et interfaces; couches minces et trichites (structure et propriétés non électroniques), Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties), Surfaces solides et interfaces solide-solide, Solid surfaces and solid-solid interfaces, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Etats électroniques, Electron states, Méthodes de calcul de structure électronique, Methods of electronic structure calculations, Structure électronique et propriétés électriques des surfaces, interfaces, couches minces et structures de basse dimensionnalité, Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures, Phénomènes de transport électronique dans les couches minces et les structures de basse dimensionnalité, Electronic transport phenomena in thin films and low-dimensional structures, 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, Adsorption, Adsorción, Catalyseur, Catalyst, Catalizador, Degré recouvrement, Coverage rate, Grado recubrimiento, Désorption, Desorption, Desorción, Etude théorique, Theoretical study, Estudio teórico, Haute pression, High pressure, Alta presión, LEED, Molybdène, Molybdenum, Molibdeno, Méthode fonctionnelle densité, Density functional method, Oxyde de molybdène, Molybdenum oxide, Molibdeno óxido, Réaction chimique, Chemical reaction, Reacción química, Spectre photoélectron RX, X-ray photoelectron spectra, Spectrométrie Auger, Auger electron spectrometry, Espectrometría Auger, TDS, Traitement surface, Surface treatment, Tratamiento superficie, Ultravide, Ultrahigh vacuum, Ultravacío, 7115M, Substrat Molybdène, and Substrat platine

Modification of Pt group catalysts by molybdenum is known to improve catalyst performance in a number of important chemical reactions. To investigate fundamental mechanisms responsible for the promoting effect of Mo, temperature-programmed desorption (TPD) and low energy electron diffraction (LEED) experiments were performed to examine the adsorption of O2, D2, CO, and water on Pt(111) modified with submonolayer quantities of molybdenum. Auger electron spectroscopy (AES) was used to detect and quantify the Mo coverage and X-ray photoelectron spectroscopy (XPS) was employed in conjunction with density functional theory (DFT) calculations to identify Mo species present following various surface treatments. The state of Mo on the surface was found to vary depending on prior surface treatment Treatment with oxygen resulted in a surface molybdenum oxide, whereas treatment with hydrogen resulted in a reduced bimetallic surface. XPS results indicate that high pressures of oxygen create a higher valent oxide than what is created under ultrahigh vacuum. Oxidized Mo appeared to block Pt surface sites without significantly altering the behavior of species adsorbed on Pt. Reduced surfaces, on the other hand, were shown to decrease yield and desorption temperature for both D2 and CO. Isotopic TPD studies provided evidence of water dissociation on the reduced Mo modified surface, with a maximum extent of water dissociation occurring at intermediate Mo coverages.

Biotechnology, Biotechnologies, Ecology, Ecologie, Energy, Énergie, Environment, Environnement, Pollution, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biophysique moleculaire, Molecular biophysics, Chimie physique en biologie, Physical chemistry in biology, Electrochimie, Electrochemistry, Bactérie, Bacteria, Alkyle, Alkyl, Alquilo, Anode, Anodo, Bacterium, Biofilm, Bioélectrochimie, Bioelectrochemistry, Bioelectroquímica, Caractérisation, Characterization, Caracterización, Carbone, Carbon, Carbono, Cation organique, Organic cation, Catión orgánico, Charge superficielle, Surface charge, Carga superficial, Communauté microbienne, Microbial community, Comunidad microbiana, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Densité courant, Current density, Densidad corriente, Etat vitreux, Glassy state, Estado vitreo, Fonctionnalisation, Functionalization, Funciónalización, Hybridation in situ fluorescence, Fluorescence in situ hybridization, Hibridación in situ fluorescencia, Hydrophobicité, Hydrophobicity, Hidrofobicidad, Hydroxyde, Hydroxides, Hidróxido, Matériau électrode, Electrode material, Material electrodo, Production énergie électrique, Electric power production, Producción energía eléctrica, Sulfonate, Sulfonato, Traitement surface, Surface treatment, Tratamiento superficie, Voltammétrie cyclique, Cyclic voltammetry, Voltametría cíclica, and Geobacter

The focus of this study was to investigate the effects of surface charge and surface hydrophobicity on anodic biofilm formation, biofilm community composition, and current generation in bioelectrochemical systems (BESs). Glassy carbon surfaces were modified with -OH, -CH3, -SO3-, or -N+(CH3)3 functional groups by electrochemical reduction of aryl diazonium salts and then used as anodes with poised potential of -0.2 V (vs Ag/AgCl). The average startup times and final current densities for the -N+(CH3)3, -OH, -SO3-, and -CH3, electrodes were (23 d, 0.204 mA/cm2), (25.4 d, 0.149 mA/cm2), (25.9 d, 0.114 mA/ cm2), and (37.2 d, 0.048 mA/cm2), respectively. Biofilms on different surfaces were analyzed by nonturnover cyclic voltammetry (CV), fluorescence in situ hybridization (FISH), and 16S rRNA gene amplicon pyrosequencing. The results demonstrated that 1) differences in the maximum current output between surface modifications was correlated with biomass quantity, and 2) all biofilms were dominated by Geobacter populations, but the composition of -CH3-associated biofilms differed from those formed on surfaces with different chemical modification. This study shows that anode surface charge and hydrophobicity influences biofilm development and can lead to significant differences in BESs performance. Positively charged and hydrophilic surfaces were more selective to electroactive microbes (e.g. Geobacter) and more conducive for electroactive biofilm formation.

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, Sciences appliquees, Applied sciences, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Appareillage et mise en oeuvre, Machinery and processing, Matières plastiques, Plastics, Revêtement, métallisation, coloration, Coating, metallization, dyeing, Analyse surface, Surface analysis, Análisis superficie, Composition chimique, Chemical composition, Composición química, Ethylène(tétrafluoro) polymère, Tetrafluoroethylene polymer, Etileno(tetrafluoro) polímero, Etude expérimentale, Experimental study, Estudio experimental, Modélisation, Modeling, Modelización, Optimisation, Optimization, Optimización, Rayon X, X ray, Rayos X, Relation mise en oeuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Régression PLS, PLS regression, Regresión PLS, Simulation numérique, Numerical simulation, Simulación numérica, Spectrométrie photoélectron, Photoelectron spectrometry, Espectrometría fotoelectrón, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, and Tratamiento superficie

We investigated the effect of various plasma parameters (relative density of atomic N and H, plasma temperature, and vibrational temperature) and process conditions (pressure and H2/(N2 + H2) ratio) on the chemical composition of modified poly(tetrafluoroethyiene) (PTFE). The plasma parameters were measured by means of near-infrared (NIR) and UV-visible emission spectroscopy with and without actinometry. The process conditions of the N2— H2 microwave discharges were set at various pressures ranging from 100 to 2000 mTorr and H2/(N2+H2) gas mixture ratios between 0 and 0.4. The surface chemical composition of the modified polymers was determined by X-ray photoelectron spectroscopy (XPS). A mathematical model was constructed using the partial least-squares regression algorithm to correlate the plasma information (process condition and plasma parameters as determined by emission spectroscopy) with the modified surface characteristics. To construct the model, a set of data input variables containing process conditions and plasma parameters were generated, as well as a response matrix containing the surface composition of the polymer. This model was used to predict the composition of PTFE surfaces subjected to N2—H2 plasma treatment Contrary to what is generally accepted in the literature, the present data demonstrate that hydrogen is not directly involved in the defluorination of the surface but rather produces atomic nitrogen and/or NH radicals that are shown to be at the origin of fluorine atom removal from the polymer surface. The results show that process conditions alone do not suffice in predicting the surface chemical composition and that the plasma characteristics, which cannot be easily correlated with these conditions, should be considered. Process optimization and control would benefit from plasma diagnostics, particularly infrared emission spectroscopy.

General chemistry, physical chemistry, Chimie générale, chimie physique, Crystallography, Cristallographie cristallogenèse, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Etats électroniques, Electron states, Surface de fermi; masse effective, facteur g, Fermi surface: calculations and measurements; effective mass, g factor, 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, Fils quantiques, Quantum wires, Divers, Other topics in nanoscale materials and structures, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Ammoniac, Ammonia, Amoníaco, Ammoniak, Bande absorption, Absorption band, Banda absorción, Cinétique, Kinetics, Cinética, Kinetik, Contrôle chute potentiel, Potential drop method, Control caída voltaje, Potentialsondenpruefung, Densité porteur charge, Charge carrier density, Concentración portador carga, Densité trou, Hole density, Densidad huecos, Loecherdichte, Durée vie porteur charge, Carrier lifetime, Electrolyte, Electrólito, Elektrolyt, Etat surface, Surface conditions, Estado superficie, Oberflaechenzustand, Groupe hydroxyle, Hydroxyl group, Grupo hidróxilo, Nanobâtonnet, Nanorod, Nanopalito, Nanomatériau, Nanostructured materials, Nanostructure, Nanoestructura, Niveau Fermi, Fermi level, Nivel Fermi, Optimisation, Optimization, Optimización, Optimierung, Photoélectrode, Photoelectrode, Fotoelectrodo, Piège, Trap, Trampa, Propriété interface, Interface properties, Propiedad interfase, Recombinaison porteur charge, Charge carrier recombination, Recombinación portador carga, Recombinaison électron trou, Electron-hole recombination, Structure électronique, Electronic structure, Estructura electrónica, Elektronenstruktur, Séparation charge, Charge separation, Separación carga, Titane, Titanium, Titanio, Titan, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Transfert charge, Charge transfer, Transferencia carga, 8107V, and 8245G

Ammonia-induced reduction treatment of titanium dioxide rutile nanorods has been performed, where the treatment triggered a synergistic surface modification of titania electrodes that enhanced its overall photoelectrochemical performance, besides introducing a new absorption band in the 420―480 nm range. A physical model has been proposed to reveal the role of each fundamental interfacial property on the observed behavior. On the one hand, by tuning the Fermi level position, charge separation was optimized by adjusting the depletion region width to maximize the potential drop inside titanium dioxide and also filling the surface states, which in turn decreased electron―hole recombination. On the other hand, by increasing the density of surface holes traps (identified as surface hydroxyl groups), the average hole lifetime was extended, depicting a more efficient hole transfer to electrolyte species. The proposed model could serve as a rationale for controlled interfacial adjustment of nanostructured photoelectrodes tailoring them for the required application.