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Mechanical engineering, Génie mécanique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Acier ressort, Spring steel, Acero resorte, Federstahl, Diagramme SN, SN diagram, Diagrama SN, Woehler Kurve, Essai fatigue, Fatigue test, Ensayo fatiga, Dauerschwingversuch, Fatigue, Fatiga, Ermuedung, Grenaillage, Shot peening, Granalla, Kugelstrahlen, Propriété mécanique, Mechanical properties, Propiedad mecánica, Ressort, Spring, Resorte, Feder, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Helical compression springs, S-N curves, Spring steels, and Very high cycle fatigue test

Long-term fatigue tests on shot peened helical compression springs were conducted by means of a special spring fatigue testing machine at 40 Hz. Test springs were made of three different spring materials ― oil hardened and tempered SiCr- and SiCrV-alloyed valve spring steel and stainless steel. With a special test strategy in a test run, up to 500 springs with a wire diameter of d = 3.0 mm or 900 springs with d = 1.6 mm were tested simultaneously at different stress levels. Based on fatigue investigations of springs with d = 3.0 mm up to a number of cycles N = 109 an analysis was done after the test was continued to N = 1.5 × 109 and their results were compared. The influence of different shot peening conditions were investigated in springs with d = 1.6 mm. Fractured test springs were examined under optical microscope, scanning electron microscope (SEM) and by means of metallographic microsections in order to analyse the fracture behaviour and the failure mechanisms. The paper includes a comparison of the results of the different spring sizes, materials, number of cycles and shot peening conditions and outlines further investigations in the VHCF-region.

Mechanical engineering, Génie mécanique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Propriétés mécaniques. Rhéologie. Mécanique de la rupture. Tribologie, Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology, Fatigue, Fatigue, Fatiga, Ermuedung, Fonte, Cast iron, Fundición, Gusseisen, Grenaillage, Shot peening, Granalla, Kugelstrahlen, Microcristallisation, Microcrystallization, Microcristalización, Microstructure, Microestructura, Mikrogefuege, Nanocristal, Nanocrystal, Propriété mécanique, Mechanical properties, Propiedad mecánica, Résistance fatigue, Fatigue strength, Resistencia fatiga, Dauerfestigkeit, Résistance mécanique, Strength, Resistencia mecánica, Festigkeit, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Nodular cast iron, Severe shot peening, and Surface nanocrystallization

Effect of nanocrystalline surface obtained by severe plastic deformation on fatigue strength of nodular cast iron has been studied in the paper. Surface nanocrystallization has been applied by means of standard air blast shot peening equipment with particularly severe parameters compared to the usual ones used for similar classes of material. Microscopy observation, microhardness, surface roughness and X-ray diffraction measurements were carried out to characterize the treated surface of differently shot peened specimens. Rotating bending fatigue tests were performed to investigate the effects of process parameters on fatigue behaviour. The results indicate a sensible fatigue strength improvement obtained through application of severe shot peening with respect to conventional shot peening, notwithstanding the specimen's very high surface roughness due to high energy impacts. The obtained results are critically discussed.

Civil engineering, Génie civil, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Corrosion, Action des agents de corrosion, Corrosion environments, Alliage base aluminium, Aluminium base alloys, Corrosion, Corrosión, Korrosion, Cérium, Cerium, Cerio, Cer, Dépôt conversion, Conversion coating, Depósito conversión, Konversionsbeschichten, Lanthanide, Lantánido, Prétraitement, Pretreatment, Pretratamiento, Revêtement, Coatings, Revestimiento, Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

Cerium-based conversion coatings were deposited on Al 7075-T6 and characterized to determine the effect of different surface pre-treatments on the corrosion rate and surface morphology. The methods of potentiodynamic polarization and scanning electron microscopy were employed. The experimental results suggest that cerium-based conversion coating is corrosion resistant in NaCl solution. Corrosion current decreased with alkaline cleaning and acid activation of aluminum surface before cerium oxide deposition. Alkaline cleaning and activation improved deposition of cerium-based conversion coatings compared to only alkaline cleaning. Analysis of the surface morphology of the coatings showed that the coatings deposited on the alkaline cleaning and acid treated panels exhibited lower visible cracks compared to coatings on only alkaline cleaned panels.

Civil engineering, Génie civil, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Corrosion, Action des agents de corrosion, Corrosion environments, Addition nickel, Nickel addition, Adición niquel, Nickelzusatz, Application, Aplicación, Anwendung, Centrale électrique, Electric power plant, Central eléctrica, Corrosion, Corrosión, Korrosion, Paroi four, Furnace wall, Pared horno, Ofenwand, Revêtement, Coatings, Revestimiento, Ueberzug, Tube, Tubo, and Rohr

The use of waste wood as a fuel in power plants is becoming more widespread in Europe, because it is a renewable energy source with a lower cost than forest fuel. However it is more corrosive than coal and corrosion problems have arisen in the furnace wall area of a low NOx heat and power boiler. The furnace walls are made of a low alloy steel which has been coated in some parts with a nickel alloy to reduce corrosion. In this work, furnace tubes coated with a nickel alloy were compared to the uncoated tubes of the low alloy steel 16Mo3 after 3 years of exposure in the boiler. The nickel alloy coating and uncoated material were also compared with more controlled testing on a corrosion probe lasting for about 6 weeks. The corrosion rates were measured and the samples were chemically analysed by SEM/EDS/WDS and XRD methods. The corrosive environment was also modelled with Thermo-Calc software. The corrosion rates measured from the probe and tube samples of 16Mo3 agreed well with each other, implying linear corrosion rates. The results also showed that the use of nickel alloy coatings changes the corrosion mechanism, which leads to a dramatic reduction in the corrosion rate. The results are discussed in terms of the corrosion mechanisms and thermodynamic stability of the corrosion products.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, 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, Stratifiés, Laminates, Agent accrochage, Coupling agent, Agente enganche, Composite hybride, Hybrid composite, Compuesto híbrido, Copolymère greffé, Graft copolymer, Copolímero injertado, Epoxyde résine, Epoxy resin, Epóxido resina, Etude expérimentale, Experimental study, Estudio experimental, Fibre minérale, Mineral fiber, Fibra inorgánica, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Mode rupture, Fracture mode, Modo ruptura, Moulage injection, Injection molding, Moldeo por inyección, Nanocomposite, Nanocompuesto, Nanotube carbone, Carbon nanotubes, Propriété mécanique, Mechanical properties, Propiedad mecánica, Silane organique, Organic silane, Silano orgánico, Stratifié, Laminate, Estratificado, Tissu textile, Woven material, Tela textil, Tissu verre, Glass fiber fabric, Tela vidrio, Traitement surface, Surface treatment, Tratamiento superficie, Ténacité, Fracture toughness, Tenacidad, Nanotubes carbone greffés, Ténacité interlaminaire, A. Laminates, B. Fracture toughness, D. Electron microscopy, and E. Injection moulding

A novel and simple chemical route was successfully applied to graft carbon nanotubes (CNTs) onto silanized plain weave glass fabric (PWGF) mats, as confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy. The CNTs grafted PWGF mats were used to reinforce epoxy matrix for multi-scale composite production due to their potential for increasing interlaminar fracture toughness by bridging the ply interfaces. Grafting CNTs onto PWGFs improved both initial and steady-state toughness more than double as measured by Mode I interlaminar fracture testing. Failed specimens were visualized to determine the failure modes using fractography. The key findings indicated that the covalent interactions created between CNTs and fibers lead fibers bridging the interface region like barbed wires, which are mainly responsible for increased fracture toughness as a result of improved interfacial adhesion.

Civil engineering, Génie civil, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Corrosion, Corrosión, Korrosion, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

Tin has a strong influence on the electrodeposition of zinc already in concentrations of less than 1 ppm. Tin changes the mechanism, the deposition rate and the morphology of the resulting surface of zinc deposited from an acidic sulfate electrolyte. These severe changes are not obvious since both elements have similar overpotentials for hydrogen evolution as the dominant side reaction. The influence on the electrodeposition of zinc was studied using cyclic voltammetry on a rotating disc electrode, chemical analysis of the zinc layers, chronopotentiometric measurements, and investigations into the microstructure by SEM. It is shown that tin co-deposits with zinc starting at concentrations of about 1 ppm and therefore changes the structure of the zinc layer. A mechanism is presented that explains the significant drop in current efficiency in a pulsed deposition program, in which the codepositing tin acts as cathode during the off cycle leading to drastic anodic redissolution of the zinc.

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, Argile organique, Organic clay, Arcilla orgánica, Caoutchouc nitrile, Nitrile rubber, Caucho nitrilo, Compatibilisant, Compatibilizer, Compatibilizante, Composé de l'ammonium quaternaire, Quaternary ammonium compound, Amonio cuaternario compuesto, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Montmorillonite, Montmorilonita, Nanocomposite, Nanocompuesto, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété rhéologique, Rheological properties, Propiedad reológica, Propriété thermique, Thermal properties, Propiedad térmica, Propriété traction, Tensile property, Propiedad tracción, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, SBR, Température transition vitreuse, Glass transition temperature, Temperatura transición vítrosa, Traitement surface, Surface treatment, Tratamiento superficie, Viscoélasticité, Viscoelasticity, Viscoelasticidad, Vulcanisat, Vulcanizate, and Vulcanizado

Different montmorillonites either, completely hydrophilic (Mont-0), amphiphilic (Mont-25, Mont-50, and Mont-75) or completely hydrophobic (Mont-100) were used as reinforcing fillers for styrene butadiene rubber (SBR) and acrylonitrile butadiene rubber (NBR) individually to predict the influence of the different forms on the properties of the rubbers (rheometric characteristics and mechanical properties). The shifts in the glass transition temperatures after the clay insertion were determined from dynamic mechanical thermal analysis to investigate the preference and action of each form. In addition, the storage moduli were used as indications to the corresponding mechanical properties of the samples. The influences could be followed after comparing the impacts of aging conditions on the properties of rubber compositions. The obtained data may provide a platform to suggest the mechanism by which these forms can in some cases act as compatibilizers in addition to their reinforcing/plasticizing effect when employed with the physically incompatible NBR/SBR (50/50) blend, which helps to optimize the properties of nanocomposites based on these blends. The proposed mechanism of action showed good correlation with the results of the mechanical properties and x-ray diffraction investigations as well. .

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, 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, Conductivité électrique, Electrical conductivity, Conductividad eléctrica, Dérivé du triazole, Triazole derivatives, Triazol derivado, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Graphène, Graphene, Matériau composite, Composite material, Material compuesto, Modification chimique, Chemical modification, Modificación química, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Polymère conducteur, Conducting polymers, Polymère conjugué, Conjugated polymer, Polímero conjugado, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Propriété thermique, Thermal properties, Propiedad térmica, Propriété électrique, Electrical properties, Propiedad eléctrica, Préparation, Preparation, Preparación, Stabilité thermique, Thermal stability, Estabilidad térmica, Styrènesulfonate polymère, Styrenesulfonate polymer, Estireno sulfonato polímero, Thiophène dérivé polymère, Thiophene derivative polymer, Tiofeno derivado polímero, Traitement surface, Surface treatment, Tratamiento superficie, Ethylènedioxythiophène polymère, Graphène oxyde, Réaction click, A. Nano composites, A. Polymer―matrix composites (PMCs), B. Electrical properties, and D. Photoelectron spectroscopy (XPS)

The well dispersed graphene in poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) composites was achieved by chemical modification via click chemistry under mild condition in order to improve the electrical conductivity of polymer. Graphene sheets were prepared from natural graphite flake by a modified Hummers method followed by reducing with hydrazine. Graphene and PEDOT:PSS were functionalized with alkyne and azide, respectively followed by reacting via click chemistry at room temperature for 48 h using copper sulfate as catalyst. The successful functionalization and click reaction between terminal alkyne groups (―C≡C) on graphene sheets and terminal azide groups (—N3) of PED-OT:PSS were confirmed by Fourier Transform Infrared (FTIR), Raman and X-ray photoelectron (XPS) spectroscopy. The preliminary test to check the dissimilar dispersibility between graphene oxide and alkyne-modified graphene oxide in mixed water/hexane solvent was performed. Thermogravimetric analysis result exhibited the composites having excellent thermal stabilities due to the incorporation of graphene in PEDOT:PSS; however, clicked composites showed slightly lower thermal stabilities than unclicked ones as a result of cleavages of amide linkages and remaining oxygen-containing functionalities. It was also found that the surface morphologies observed by scanning electron microscope of clicked composites were smoother than those of unclicked composites because of the enhancement of interfacial interaction between graphene sheets and PEDOT:PSS matrix, resulting in a decrease in graphene agglomeration and, in turn, an increase in electrical conductivity.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Amidon et polyosides divers, Starch and polysaccharides, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés biologiques, Biological properties, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Chirurgie (generalites). Transplantations, greffes d'organes et de tissus. Pathologie des greffons, Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases, Technologie. Biomatériaux. Equipements, Technology. Biomaterials. Equipments, Bactérie, Bacteria, Micrococcaceae, Micrococcales, Oside polymère, Oside polymer, Osido polímero, Propriété biologique, Biological properties, Propiedad biológica, Propriété surface, Surface properties, Propiedad superficie, Pseudomonadaceae, Pseudomonadales, Adhérence cellulaire, Cell adhesion, Adherencia celular, Antibactérien, Antibacterial agent, Antibacteriano, Bactéricidie, Bactericidal effect, Bactericidia, Biomatériau, Biomaterial, Chitosane, Chitosan, Quitosano, Copolymère greffé, Graft copolymer, Copolímero injertado, Copulation chimique, Chemical coupling, Copulación química, Etheruréthanne polymère, Etherurethane polymer, Eteruretano polímero, Etude expérimentale, Experimental study, Estudio experimental, Mouillabilité, Wettability, Remojabilidad, Préparation, Preparation, Preparación, Pseudomonas aeruginosa, Réaction surface, Surface reaction, Reacción superficie, Staphylococcus aureus, Topographie surface, Surface topography, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Uréthanne copolymère, Urethane copolymer, Uretano copolímero, Energie libre surface, Antibacterial, Bacterial adhesion, Polyurethane, and Surface modification

Surface modification and providing antibacterial properties to the materials or devices are getting great attention especially in the last decades. In this study, polyurethane (PU) films were prepared by synthesizing them in medical purity from toluene diisocyanate and polypropylene ethylene glycol without using any other ingredients and then the film surfaces were modified by covalent immobilization of chitosan (CH) which has antibacterial activity. CH immobilized PU films (PU-CH) were found to be more hydrophilic than control PU films. Electron Spectroscopy for Chemical Analysis (ESCA) and Atomic Force Microscopy (AFM) analyses showed higher nitrogen contents and rougher surface topography for PU-CH compared to PU films. Modification with CH significantly increased antibacterial activity against Gram positive (Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa) bacteria. It was observed that the number of bacteria colonies were less about 102-105 CFU/mL and number of attached viable bacteria decreased significantly after CH modification of PU films.

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, Acrylate copolymère, Acrylate copolymer, Acrilato copolímero, Composé allylique, Allylic compound, Compuesto alílico, Copolymère réticulé, Crosslinked copolymer, Copolímero reticulado, Effet concentration, Concentration effect, Efecto concentración, Effet mémoire forme, Shape memory effect, Efecto memoria forma, Etude expérimentale, Experimental study, Estudio experimental, Limite élasticité, Yield strength, Límite elasticidad, Matériau composite, Composite material, Material compuesto, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Polymérisation photochimique, Photopolymerization, Polimerización fotoquímica, Propriété mécanique, Mechanical properties, Propiedad mecánica, Propriété thermique, Thermal properties, Propiedad térmica, Préparation, Preparation, Preparación, Prépolymère, Prepolymer, Prepolímero, Rayonnement UV, Ultraviolet radiation, Radiación ultravioleta, Température transition vitreuse, Glass transition temperature, Temperatura transición vítrosa, Traitement surface, Surface treatment, Tratamiento superficie, Uréthanne copolymère, Urethane copolymer, Uretano copolímero, Uréthanne polymère, Polyurethane, Uretano polímero, Graphène oxyde, UV cure, graphene oxide, hybrids, polyurethanes, and shape memory

Graphene oxide modified chemically with allyl isocyanate (iGO) was incorporated in various amounts into acrylate-terminated polyurethane (PU) via UV curing. The effects of this incorporation on the morphological, mechanical, dynamic mechanical, thermal and shape memory properties of the resulting hybrids were examined. The iGO nanoparticles incorporated into the PU chains acted as both multifunctional crosslinks and reinforcing fillers, and the effects were most pronounced at low iGO contents (0.5 and 1.0 wt%). Consequently, the glassy and rubbery state moduli, yield strength, glass transition temperature, shape fixity and shape recovery ratios were increased on adding up to 1 wt% iGO. At higher iGO loadings, the values of most of these properties decreased due to aggregation and the auto-inhibition of allyl compounds.

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, Copolymère séquencé, Block copolymer, Copolímero secuencia, Cristallinité, Crystallinity, Cristalinidad, Cristallisation isotherme, Isothermal crystallization, Cristalización isotérmica, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Interaction intermoléculaire, Intermolecular interaction, Interacción intermolecular, Lactone copolymère, Lactone copolymer, Lactona copolímero, Lactone polymère, Lactone polymer, Lactona polímero, Matériau composite, Composite material, Material compuesto, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Point quantique, Quantum dot, Punto cuántico, Polymère optiquement actif, Optically active polymer, Polímero ópticamente activo, Préparation, Preparation, Preparación, Styrène copolymère, Styrene copolymer, Estireno copolímero, Séléniure de cadmium, Cadmium selenides, Séparation phase, Phase separation, Separación fase, Traitement surface, Surface treatment, Tratamiento superficie, Lactide copolymère, Lactide polymère, Stéréocomplexe, block copolymer, chirality, hybrid materials, nanoparticle, and quantum dot

A new nanoparticle/block copolymer (NP/BCP) hybrid material combining the unique properties of BCP poly(styrene)-b-poly(D-lactide) (PS-b-PDLA) and inorganic NP quantum dots CdSe was developed. A systematic study on the microphase separation of a series of PS-b-PDLAs by small-angle X-ray scattering showed that the degree of order of the separated microdomains depended on the initial state of the BCP and the measurement temperature and can be improved through isothermal crystallization of PDLA, thermal annealing and shear field etc. Incorporating a small amount of NPs into the BCP matrix can improve the mobility of the polymer chains and thus promote self-assembly of the BCP, which leads to hierarchically ordered structures. Excess NPs, however, cannot be completely incorporated into the PDLA domains, resulting in the phase transformation of the BCP, destruction of the ordered structure and even macroscopic phase separation due to the aggregation of NPs. An important observation is that stereocomplexation between PDLA and poly(L-lactide) could provide a driving force to promote microphase separation of the BCP. The strategy presented in the current work has potential applications for developing highly ordered NP/BCP hybrid materials.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, 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, Acrylique acide polymère, Acrylic acid polymer, Acrílico ácido polímero, Agent accrochage, Coupling agent, Agente enganche, Alumine, Alumina, Alúmina, Céramique oxyde, Oxide ceramics, Cerámica óxido, Effet concentration, Concentration effect, Efecto concentración, Etude expérimentale, Experimental study, Estudio experimental, Matériau composite, Composite material, Material compuesto, Matériau hybride, Hybrid material, Material híbrido, Morphologie, Morphology, Morfología, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Procédé sol gel, Sol gel process, Procedimiento sol gel, Propriété chimique, Chemical properties, Propiedad química, Propriété thermique, Thermal properties, Propiedad térmica, Préparation, Preparation, Preparación, Silane organique, Organic silane, Silano orgánico, Stabilité thermique, Thermal stability, Estabilidad térmica, Traitement surface, Surface treatment, Tratamiento superficie, A. Hybrid, B. Surface properties, and E. Surface treatments

Hybrid inorganic-organic materials are promising systems for a variety of applications due to their extraordinary properties from the combination of different building blocks. In this work, we present the synthesis and characterization of a hybrid material based on poly[acrylic acid] (PAA), 3-(trimethoxysilyl)propyl methacrylate (TMPM), and aluminum oxide (Al2O3). The synthesis was carried out using a two-step process: first, a polymerization via radical initiation, and subsequently, a sol-gel process. The hybrids were prepared by keeping constant the amount of acrylic acid and aluminum oxide precursor but changing the amount of TMPM. The physical and chemical properties of the hybrids were investigated using infrared spectroscopy (FT-IR), X-ray diffraction (XRD), N2 absorption (SBET), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The results indicate that all of the materials were simultaneous interpenetrating networks (SIPNs) and that the morphologies and the properties depend on the amount of TMPM used. All materials showed good thermal stability, and the surface area of the composite decreased as more TMPM was incorporated in the network.

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, Aniline copolymère, Aniline copolymer, Anilina copolímero, Corrosion électrochimique, Electrochemical corrosion, Corrosión electroquímica, Etude expérimentale, Experimental study, Estudio experimental, Imide copolymère, Imide copolymer, Imida copolímero, Matériau composite, Composite material, Material compuesto, Perméabilité gaz, Gas permeability, Permeabilidad gas, Polycondensation, Condensation polymerization, Policondensación, Procédé sol gel, Sol gel process, Procedimiento sol gel, Propriété transport, Transport properties, Propiedad transporte, Propriété électrochimique, Electrochemical properties, Propiedad electroquímica, Préparation, Preparation, Preparación, Revêtement anticorrosion, Corrosion protective coatings, Résistance corrosion, Corrosion resistance, Resistencia corrosión, Silice, Silica, Sílice, Traitement surface, Surface treatment, and Tratamiento superficie

In this study, a series of electroactive polyimide/SiO2 (EPIS) composite materials containing conjugated segments of electroactive amino-capped aniline trimer (AT) unit were successfully prepared. First of all, the amino-modified silica (AMS) particles of ~100 nm in diameter were synthesized by performing the conventional base-catalyzed sol―gel reactions. Subsequently, the AMS nanoparticles were blending into the polymerization reactions between AT and 4,4ʹ-(4,4ʹ-isopropylidenediphenoxy)-bis(phthalic anhydride), leading to the formation of EPIS composites. The as-prepared EPIS materials in the form of coating on cold-rolled steel (CRS) electrode were found to be much superior in corrosion protection over those of non-electroactive polyimide and EPI materials based on a series of electrochemical corrosion measurements in saline. The significant enhancement in corrosion protection of EPIS coatings on CRS electrodes might probably be attributed to the redox catalytic property of organic EPI inducing the formation of passive metal oxide layer and the barrier property of well-dispersed AMS nanoparticles existed in EPI matrix.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Composite matrice métallique, Metal matrix composite, Compuesto matriz metalico, Céramique sans oxyde, Non oxide ceramics, Cerámica sin óxido, Etude expérimentale, Experimental study, Estudio experimental, Experimentelle Untersuchung, Laser, Láser, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Matériau renforcé dispersion, Dispersion reinforced material, Material renforzado dispersión, Dispersionsgehaerteter Werkstoff, Matériau revêtement, Coating material, Material revestimiento, Morphologie, Morphology, Morfología, Nickel alliage, Nickel alloy, Níquel aleación, Nickellegierung, Nitrure de silicium, Silicon nitride, Silicio nitruro, Siliciumnitrid, Propriété mécanique, Mechanical properties, Propiedad mecánica, Préparation, Preparation, Preparación, Vorbereitung, Résistance usure, Wear resistance, Resistencia al desgaste, Verschleissfestigkeit, Titane alliage, Titanium alloy, Titanio aleación, Titanlegierung, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Tribologie, Tribology, Tribología, A. Intermetallics, A. Metal-matrix composites (MMCs), B. Wear, and D. Surface analysis

Si3N4-Ni60 is firstly used to improve the wear resistance of a TA7 (Ti-5Al-2.5Sn) titanium alloy surface by mean of a laser alloying (LA) technique. The synthesis of the hard composite coating on a TA7 titanium alloy by LA of Ni60-Si3N4 pre-placed powders was investigated by means of scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and high resolution transmission electron microscope (HRTEM). Experimental results indicated that a number of the interdendritic lamellar eutectics, nanoscale ceramics (NC) and the amorphous phases were produced in such LA coating. The production of NC led the free energy to enhance, which increased the density of point defect, leading to the formation of hypersaturated state of point defect, causing lattice distortions. Compared with a TA7 alloy substrate, an improvement of the wear resistance was obtained for such LA composite coating.

Civil engineering, Génie civil, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Alliage base nickel, Nickel base alloys, Corrosion, Corrosión, Korrosion, Densité, Density, Densidad, Etat supercritique, Supercritical state, Estado supercrítico, Plasma, Projection plasma, Plasma spraying, Proyección plasma, Plasmaspritzen, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

In this study, IN625 and a NiCrAlY coated IN625 were tested in high density and low density supercritical water for 500 h.The NiCrAlY coating was applied using plasma spray method. The surfaces were finely polished before testing to assist microstructure observation after testing. The NiCrAlY coated samples were additionally heat treated in air furnace to encourage alumina formation. SEM and XRD analyses were carried out to determine surface microstructure changes, particularly oxide formation. The results showed that when tested under high density supercritical water, the bare IN625 sample suffered from intergranular attacking while low density supercritical water did not have the same effect. Both as-sprayed NiCrAlY and heat treated NiCrAlY did not show any signs of intergranular attack or pitting after being tested in high density and low density supercritical water.

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, Propriété surface, Surface properties, Propiedad superficie, Energie surface, Surface energy, Energía superficie, Etude expérimentale, Experimental study, Estudio experimental, Lactique acide polymère, Lactic acid polymer, Láctico ácido polímero, Mouillabilité, Wettability, Remojabilidad, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Relation mise en oeuvre structure, Structure processing relationship, Relación puesta en marcha estructura, Topographie surface, Surface topography, Traitement par plasma, Plasma assisted processing, Traitement surface, Surface treatment, Tratamiento superficie, Nanorugosité, Atmospheric plasma, and Polylactic acid

The main objective of this experimental study is the validation of the technique of atmospheric plasma with the aim of improving the surface energy of the polylactic acid (PLA) for further adhesion uses. The wettability of PLA has been improved with the application of an atmospheric plasma surface treatment. This method provides good adhesion properties with the optimizing the process parameters in terms of the nozzle-substrate distance and sample advance rate. In order to achieve that goal, a new and environmentally friendly technology has been used which is based on the use of air atmospheric plasma. The effects of the surface treatment on this type of substrates have been analyzed. The macroscopic effects of the process parameters have been determined using contact angle measurements and subsequent surface free energy (SFE) calculation. In addition, the chemical changes at the topmost layers have been studied using X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectroscopy (FTIR). Surface topography changes due to the plasma-acting mechanisms have been evaluated with scanning electron microscopy (SEM) and atomic force microscopy (AFM). The obtained results show a remarkable increase in surface free energy from 37.1 mJ m-2 up to values of 60 mJ m-2 thus indicating the effectiveness of the air plasma treatment. The main advantage of this technology is that the industrial process is continuous, it is easy to establish in current production systems and it does not generate wastes.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Fabrication microélectronique (technologie des matériaux et des surfaces), Microelectronic fabrication (materials and surfaces technology), 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, Domaines d'application, Application fields, Adhésif, Adhesive, Adhesivo, Argent, Silver, Plata, Conductivité thermique, Thermal conductivity, Conductividad térmica, Epoxyde résine, Epoxy resin, Epóxido resina, Etude expérimentale, Experimental study, Estudio experimental, Fabrication microélectronique, Microelectronic fabrication, Fabricación microeléctrica, Iode, Iodine, Iodo, Matériau composite, Composite material, Material compuesto, Microparticule, Microparticle, Micropartícula, Morphologie, Morphology, Morfología, Particule métallique, Metal particle, Partícula metálica, Particule sphérique, Spherical particle, Partícula esférica, Propriété thermique, Thermal properties, Propiedad térmica, Traitement chimique, Chemical treatment, Tratamiento químico, Traitement surface, Surface treatment, Tratamiento superficie, Adhésif conducteur, A. Polymer―matrix composites (PMCs), B. Thermal properties, and D. Scanning electron microscopy (SEM)

Heat dissipation is a critical issue in many areas such as the high-performance electronic devices. The present work gives a detailed investigation regarding a simple and efficient surface modification method, which can remarkably improve the thermal conductivity of the isotropically thermally conductive adhesives (TCAs). Herein we demonstrate that the thermal conductivity of TCAs based on micron-sized silver fillers can be improved to near eightfold merely through simple surface chemistry treatment of the fillers, without changing the conventional epoxy resin (adhesive) processing conditions. Experimental results show that the thermal conductivity of a TCA sample with iodine modified silver fillers (85 wt%, size 1-2 μm. near-spherical particles) achieved 13.5 Wm-1 K-1 when cured at 150 °C. Compared to the unmodified silver-based TCAs, only 1.7 Wm-1 K-1 was achieved when cured in the same condition. This work suggests that through modulating the filler interface of a TCA, the thermal conductivity of a TCA can be drastically improved. These TCAs with superior isotropic thermal conductivity may find many heat dissipation applications e.g. surface mounted devices (SMDs) and high power (printed circuit) motherboards.

Chemical industry parachemical industry, Industrie chimique et parachimique, Mechanics acoustics, Mécanique et acoustique, Metallurgy, welding, Métallurgie, soudage, 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, Amination, Aminación, Composition chimique, Chemical composition, Composición química, Epoxyde résine, Epoxy resin, Epóxido resina, Etude expérimentale, Experimental study, Estudio experimental, Fibre carbone, Carbon fiber, Fibra carbón, Fibre minérale, Mineral fiber, Fibra inorgánica, Fibre revêtue, Coated fiber, Fibra revestida, Interface fibre matrice, Matrix fiber interface, Interfase fibra matriz, Matériau composite, Composite material, Material compuesto, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Propriété interface, Interface properties, Propiedad interfase, Propriété mécanique, Mechanical properties, Propiedad mecánica, Relation mise en oeuvre propriété, Property processing relationship, Relación puesta en marcha propiedad, Résistance cisaillement, Shear strength, Resistencia cizallamiento, Stratifié, Laminate, Estratificado, Traitement surface, Surface treatment, Tratamiento superficie, Résistance cisaillement interfacial, Résistance cisaillement interlaminaire, A. Carbon fibers, A. Polymer―matrix composites, B. Surface properties, E. Surface treatments, and Supercritical fluids

To improve the interfacial properties between carbon fibers and epoxy matrix, the fibers were treated by an ammoniac medium, which consisted of supercritical water, ethanol and triethylene tetramine. The images of atomic force microscopy and scanning electron microscope indicate that coating layers are formed on the surfaces of treated fibers. The results of X-ray photoelectron spectroscopy demonstrate that N content on the surfaces of carbon fibers increases and the main ammoniac groups of the coating layers are amino and imino groups. The mechanical measurements indicate that both interlaminar and interface shear strength of carbon fibers are significantly increased after amination.

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, Acide sulfonique, Sulfonic acid, Acido sulfónico, Agent accrochage, Coupling agent, Agente enganche, Benzooxazole dérivé polymère, Benzoxazole derivative polymer, Benzooxazol derivado polímero, Epoxyde résine, Epoxy resin, Epóxido resina, Etude expérimentale, Experimental study, Estudio experimental, Fibre synthétique, Synthetic fiber, Fibra sintética, Interface fibre matrice, Matrix fiber interface, Interfase fibra matriz, Matériau renforcé fibre, Fiber reinforced material, Material reforzado fibra, Molécule polyédrique, Polyhedral molecule, Molécula poliédrica, Mélange polymère, Polymer blends, Oligomère, Oligomer, Oligómero, Polymère aromatique, Aromatic polymer, Polímero aromático, Propriété interface, Interface properties, Propiedad interfase, Propriété surface, Surface properties, Propiedad superficie, Rugosité, Roughness, Rugosidad, Silane organique, Organic silane, Silano orgánico, Silsesquioxane polymère, Silsesquioxane polymer, Silsesquioxano polímero, Traitement surface, Surface treatment, Tratamiento superficie, and Benzobisoxazole(p-phénylène) polymère

A novel three-step approach of methanesulfonic acid/γ-aminopropyl triethoxy silane/GlycidylEthyl polyhedral oligomeric silsesquioxane (MSA/KH550/POSS) was proposed to functionalize the surface of high modulus poly (p-phenylene-2,6-benzobisoxazole) (HMPBO) fibers. Results indicated that GlycidylEthyl POSS was successfully grafted on the surface of HMPBO fibers and the surface roughness of HMPBO fibers was increased obviously. The single fiber pull-out strength of POSS-g-HMPBO/epoxy resin microcomposite was improved to 1.19 MPa, better than that of native HMPBO/epoxy resin microcomposite.

Civil engineering, Génie civil, Metallurgy, welding, Métallurgie, soudage, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Dépôt de métaux et d'alliages, Metallic coatings, Corrosion, Action des agents de corrosion, Corrosion environments, Alliage base aluminium, Aluminium base alloys, Borure de titane, Titanium boride, Titanio boruro, Titanborid, Corrosion, Corrosión, Korrosion, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Elektroplattieren, Matériau composite, Composite material, Material compuesto, Verbundwerkstoff, Revêtement métallique, Metal coating, Revestimiento metálico, Metallischer Ueberzug, Traitement surface, Surface treatment, Tratamiento superficie, and Oberflaechenbehandlung

The electrodeposition behavior of aluminum on TiB2/A356 composite from AlCl3-NaCl-KCl molten salt was studied in this paper. The surface morphology, microstructure, and phase composition of aluminum coating were characterized by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The phase composition of the composite was examined by X-ray diffraction technique. The polarization curves were measured and the corrosion current densities were obtained. The results indicated that the aluminum coating was preferentially electrodeposited on the surface of TiB2 and Si phases. This phenomenon could be largely attributed to the different surface energies of TiB2, Si, and Al phases. With the increasing of deposition time, a continuous, dense, and faceted aluminum coating was finally obtained. It was inferred that the growth of aluminum coating on the surface of the composite was mainly through two-dimensional spreading. However, three-dimensional growth could also be seen. The corrosion current density of the aluminum-coated TiB2/A356 composite (1 min) decreased by an order of magnitude as compared with that of TiB2/A356 composite, and was close to that of A356 alloy, and also in the same order of magnitude with that of pure aluminum. It is evident that, the coverage ofTiB2 and Si phases by aluminum coating (1 min) can effectively improve the corrosion resistance of TiB2/A356 composite. In combination with SEM and EDS results, the behavior can be characterized as preferential electrodeposition.