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

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

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Membranes, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Biophysique moleculaire, Molecular biophysics, Physicochimie des membranes, Membrane physicochemistry, Propriété thermodynamique, Thermodynamic properties, Propiedad termodinámica, Angle contact, Contact angle, Angulo contacto, Article synthèse, Review, Artículo síntesis, Energie libre, Free energy, Energía libre, Energie surface, Surface energy, Energía superficie, Lipide, Lipids, Lípido, Membrane biologique, Biomembrane, Membrana biológica, Membrane, Membrana, Modèle, Models, Modelo, Mouillabilité, Wettability, Remojabilidad, Mouillage, Wetting, Remojo, Contact angles, Lipid layers, Surface free energy, and Wettability changes

Various aspects of native and model biological membrane wettability are discussed. Among others hydration of mono-, bi-, and multi-layers of lipids as well as wettability of macroscopic surfaces of solid supported lipid films was investigated via apparent contact angle measurements and calculation of the apparent surface free energy of the films. The effects of relative humidity on the layer hydration and contact angle changes are also discussed. Finally, the effect of liposomes and enzymes (due to the hydrolysis reactions) on the hydrophobic/hydrophilic character of the film surfaces is overviewed.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Diffusion(transport), Diffusion, Etat adsorbé, Adsorbed state, Estado adsorbido, Microscopie tunnel balayage, Scanning tunneling microscopy, Métal transition, Transition elements, Méthode fonctionnelle densité, Density functional method, Platine, Platinum, Pt, Aromatic adsorbates, Density functional theory, and Van der Waals

We present a combined density functional theory (DFT) and scanning tunneling microscopy (STM) investigation of the adsorption and diffusion of non-interacting 2,2,2-trifluoroacetophenone (TFAP) and (R)-(+)-1-(1-naphthyl)ethylamine ((R)-NEA) on the Pt(111) surface. The two adsorbates are prochiral and chiral, respectively, and their surface diffusion is of specific interest in relation to chirality transfer from chiral modifiers to prochiral reactants in Orito-type hydrogenation on metal catalysts. Using a van der Waals-DFT description, the two adsorbates are shown to bind strongly to the surface through the aromatic groups and their respective side groups with carbonyl and amine functions. Adsorption energies were calculated for twelve different (R)-NEA adsorption conformers. A naming convention is introduced to describe the different conformers, and the two most stable ones are labeled (R)-NEA-1 and (R)-NEA-2. Diffusion of both adsorbates is calculated to proceed in a walking manner, moving either the aromatic group or the substituent group. For TFAP a diffusion barrier of 0.66 eV is calculated while 0.74-0.89 eV barriers are found for the two adsorption conformers of (R)-NEA. In agreement with the computed results, the room temperature STM study shows rapid diffusion of TFAP and significantly slower diffusion of (R)-NEA. Whereas TFAP monomers are rarely imaged at room temperature, consistent with rapid diffusion, time-lapsed images of (R)-NEA show limited molecular motion in localized regions of the surface. Furthermore, the motion of (R)-NEA is strongly conformation dependent. (R)-NEA-1 displays a much greater propensity to undergo rotational motion. The STM data for (R)-NEA are compared with DFT calculated energy barriers for translation and rotation. The possible implications of the experimental and calculated data for a role for induced fit stereodirection by (R)-NEA/Pt(111) are commented on.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Propriété rhéologique, Rheological properties, Propiedad reológica, Article synthèse, Review, Artículo síntesis, Colloïde, Colloid, Coloide, Déplétion, Depletion, Depleción, Elasticité, Elasticity, Elasticidad, Matière molle, Soft matter, Materia suave, Particule, Particle, Partícula, Polymère étoile, Star polymer, Polímero estrella, Rhéologie, Rheology, Reología, Suspension colloïdale, Colloidal suspension, Suspensión coloidal, Viscosité, Viscosity, Viscosidad, Viscoélasticité, Viscoelasticity, Viscoelasticidad, Flow curves, Glass/Jamming, Microgels, Particle elasticity, Soft colloids, Star polymers, and Yield stress/strain

In the last two decades, advances in synthetic, experimental and modeling/simulation methodologies have considerably enhanced our understanding of colloidal suspension rheology and put the field at the forefront of soft matter research. Recent accomplishments include the ability to tailor the flow of colloidal materials via controlled changes of particle microstructure and interactions. Whereas hard sphere suspensions have been the most widely studied colloidal system, there is no richer type of particles than soft colloids in this respect. Yet, despite the remarkable progress in the field, many outstanding challenges remain in our quest to link particle microstructure to macroscopic properties and eventually design appropriate soft composites. Addressing them will provide the route towards novel responsive systems with hierarchical structures and multiple functionalities. Here we discuss the key structural and rheological parameters which determine the tunable rheology of dense soft deformable colloids. We restrict our discussion to non-crystallizing suspensions of spherical particles without electrostatic or enthalpic interactions.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Agrégation limitée diffusion, Diffusion limited aggregation, Agregación limitada difusión, Article synthèse, Review, Artículo síntesis, Colloïde, Colloid, Coloide, Diffusion RX centrale, Small angle X ray scattering, Difusión rayo X central, Diffusion RX, X ray scattering, Difusión rayo X, Echelle nanométrique, Nanometer scale, Fractal, Huile, Oil, Aceite, Matière grasse, Fat, Materia grasa, Modèle, Models, Modelo, Nanocristal, Nanocrystal, Nucléation, Nucleation, Nucleación, Simulation ordinateur, Computer simulation, Simulación computadora, Triglycéride, Triglyceride, Triglicérido, Mesoscale, Nanoscale, Triacylglycerols, and X-ray scattering

Triacylglycerols (TAGs) are the majority molecules present in edible fats and oils. Many of the functional characteristics of fat products depend on the colloidal fat crystal network present. Identifying the hierarchies of these colloidal networks and how they spontaneously self-assemble is important to understand their functionality and the oil binding capacity, and new insights into the nano- to meso-scale structure in these colloidal fat networks have been reported in recent years. Ultra small angle X-ray scattering (USAXS) is a technique new to the study of edible oil structures and, when combined with modelling and computer simulation, has enabled significant advances to be made in understanding the nano- to micro-scale crystalline structures of edible oils. In the four years since crystalline nanoplatelets (CNPs) were characterized, models have been made of these highly anisotropic nanoscale structures in which they were treated as the primary unit. In those models, CNPs were represented as close-packed rigid layers of spheres, so chosen because the van der Waals sphere―sphere interaction is known. The intent of the models was to predict the hierarchy of colloidal fat networks that would self-assemble from the components in edible oils. Initially, CNP aggregation was modelled under the assumption that all CNPs are present before aggregation begins and that their solubility in liquid oil is very low. The models successfully predicted the fractal dimensions subsequently measured using USAXS. This brief review reports on some of the latest models and simulations together with the results of USAXS experiments carried out on binary lipid systems, such as SSS in OOO, as well as certain complex systems that contain many different TAG molecules. The excellent agreement between the two approaches has established that USAXS is a powerful tool in the elucidation of the nano- to meso-length scales in fats and oils.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Autoassemblage, Self-assembly, Matériau poreux, Porous materials, Modélisation, Modelling, Méthode Monte Carlo, Monte Carlo methods, Simulation numérique, Digital simulation, Surcouche, Overlayers, Adsorption, Chiral porous networks, Functional molecules, and Monte Carlo simulations

Formation of complex ordered patterns by simple molecular building blocks adsorbed on solid substrates is an intriguing phenomenon in which small changes in the geometry and chemistry of the molecular brick can lead to entirely different 2D architectures. In this contribution we demonstrate how theoretical modeling can be effectively used to predict the morphology of adsorbed overlayers comprising cross-shaped functional molecules equipped with active interaction centers. In particular, we use the Monte Carlo lattice model to explore the effect of distribution of the centers within the probe molecule on the structure of the corresponding molecular assemblies. The simulated results show that, depending on the number and position of the active centers, the outcome of the self-assembly can be extended homochiral porous networks, molecular strings and dispersed molecular clusters. Our theoretical investigations can be helpful in custom designing methods for imparting chirality to solid surfaces via the adsorption of functional molecules.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Métal transition, Transition elements, Chiral, Inorganic materials, and Topological insulators

We demonstrate that an intrinsically chiral, high Miller index surface of an achiral metal can be used to template the enantioselective growth of chiral transition metal chalcogenide films. Specifically, Cu(643)R can be used as a template for the enantioselective growth of a chiral copper telluride alloy surface. Beyond a critical alloy thickness the chiral influence of the Cu(643)R surface diminishes and an achiral surface forms. Our work demonstrates a new method of producing chiral transition metal chalcogenide surfaces, with potential applications in the study of structurally chiral topological insulators.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Gels colloïdaux. Sols colloïdaux, Colloidal gels. Colloidal sols, Article synthèse, Review, Artículo síntesis, Eau, Water, Agua, Hydratation, Hydration, Hidratación, Interface, Interfase, Ion, Ions, Ión, Lanthanide, Lantánido, Lipide, Lipids, Lípido, Matière molle, Soft matter, Materia suave, Cation hydration and coordination, Hofmeister series, Lanthanides, Soft matter interfaces, and Specific ion effects

At charged surfaces bound ions reduce the repulsive electrostatic forces, while dissociated ions control the osmotic pressure in colloidal systems. For systems charged through ionic adsorption on the other hand, the adsorbed ions determine the charging boundary condition and colloidal interactions. Soft-matter interfaces have considerable flexibility and compressibility, hence ionic adsorption at such interfaces may generate new phenomena when (a) the ions compete with the lipid or polymeric components for water of hydration, or (b) position themselves at the polar-nonpolar interface and modify its structure. We review some recent advances on the understanding of specific ion effects from this perspective, and provide some unpublished illustrative examples involving soft flexible interfaces. We propose an extension of the chaotropic series to include disruptors of soft matter, which may act as cosurfactants or even as hydrotropes. We also examine the effects of coordinating ligands on specific ion adsorption at soft interfaces, using lanthanides as test cations, and discuss how such effects may be used to change the affinities between ions and interfaces in controlled ways.

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, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Rhéologie, Rheology, Techniques et appareillage, Techniques and apparatus, Mesures rhéologiques, Rheological measurements, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Mécanique fluide, Fluid mechanics, Mecánica flúido, Article synthèse, Review, Artículo síntesis, Couche mince, Thin film, Capa fina, Microfluidique, Microfluidics, Microfluidic, Propriété rhéologique, Rheological properties, Propiedad reológica, Rhéologie, Rheology, Reología, Microrhéologie, Microrheology, Microrheometric, Piezo vibrators, Thin film rheology, and Wall slip

Microrheology probes the mesoscale between bulk rheology, which provides an integral sample response, and nanorheology, which refers to a local response at a molecular confinement level. The term 'microrheology' is often used to refer to optical particle tracking methods that measure a local response of a sample. In contrast to this, non-optical microrheology techniques generally allow two different effects to be studied: actual confinement effects on the rheology and boundary effects such as slip. Investigating the mesoscale range has additional advantages such as the possibility to perform measurements with small sample volumes and at high shear rates. This review bundles the wide array of non-optical techniques into five categories: adaptations to a conventional rotational rheometer, sliding plate rheometry on a micrometer scale, microfluidics, piezo vibrators and radial channel flows. The concept of each set of techniques is described, together with their operational window and examples of recent studies.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Gels colloïdaux. Sols colloïdaux, Colloidal gels. Colloidal sols, Apatite hydroxylée, Hydroxyapatite, Hidroxiapatito, Article synthèse, Review, Artículo síntesis, Biomatériau, Biomaterial, Céramique, Ceramic materials, Cerámica, Os, Bone, Hueso, Préparation, Preparation, Preparación, Rhéologie, Rheology, Reología, Suspension, Suspensión, Ceramics, Scaffold, Slurry, and Tissue Engineering

As a result of aging populations in the industrialized world, the development of biomaterials for bone tissue engineering is becoming increasingly important. Rheology, which is a key parameter in process engineering, plays a decisive role in designing these biomaterials. As a prime example of biomaterials engineering, this review focuses on formulations that are based on hydroxyapatite (HAp). More specifically, we will discuss the contribution of rheology for designing injectable bone replacement materials, composite gel scaffolds, porous scaffolds and scaffolds that can be generated using rapid prototyping or 3D printing techniques.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Chimie surface, Surface chemistry, Cuivre, Copper, Dépendance température, Temperature dependence, EXAFS, Métal transition, Transition elements, Spectrométrie photoélectron, Photoelectron spectroscopy, TDS, Cu, Alanine, Chiral surfaces, NEXAFS, and TPD

Adsorption of L-alanine on the Cu{111} single crystal surface was investigated as a model system for interactions between small chiral modifier molecules and close-packed metal surfaces. Synchrotron-based X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy are used to determine the chemical state, bond coordination and out-of-plane orientation of the molecule on the surface. Alanine adsorbs in its anionic form at room temperature, whilst at low temperature the overlayer consists of anionic and zwitterionic molecules. NEXAFS spectra exhibit a strong angular dependence of the π* resonance associated with the carboxylate group, which allows determining the tilt angle of this group with respect to the surface plane (48° ± 2°) at room temperature. Low-energy electron diffraction (LEED) shows ap (2 √13 x 2 √13) R13° superstructure with only one domain, which breaks the mirror symmetry of the substrate and, thus, induces global chirality to the surface. Temperature-programmed XPS (TP-XPS) and temperature-programmed desorption (TPD) experiments indicate that the zwitterionic form converts into the anionic species (alaninate) at 293 K. The latter desorbs/decomposes between 435 K and 445 K.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Catalyse, Catalysis, Chimisorption, Chemisorption, Chiralité, Chirality, Hydrogénation, Hydrogenation, Microscopie tunnel balayage, Scanning tunneling microscopy, Méthode fonctionnelle densité, Density functional method, Asymmetric hydrogenation, Chiral modifier, Density functional theory, Heterogeneous catalysis, and Prochiral substrate

Linking STM images to atomic positions determined by DFT calculations is an important step in characterizing the intermolecular interactions at play in many surface processes including asymmetric hydrogenation on heterogeneous catalysts. An accelerated data extraction method is used to collect STM information on the geometry of complexes formed between the two substrates, 2,2,2-trifluoroacetophenone (TFAP) and 3,3,3-methyltrifluoropyruvate (MTFP), and the chiral modifier (R)-(+)-1-(-naphthyl)ethylamine ((R)-NEA) on Pt(111). We present new experimental data for complexes formed by MTFP and the (R)-NEA-1 conformer along with a new and enlarged set of reformulated STM data that extends what was reported in previously published studies of complexed MTFP and TFAP. Atomic geometries based on DFT calculations using PBE, M06-L, and optB88-vdW exchange-correlation functionals will also be presented. It will be shown that both substrates have well-defined complexation geometries when interacting with the modifier and that the relative complexation energies are not markedly sensitive to the functional employed.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Spectre IR, Infrared spectra, Spectre absorption, Absorption spectra, Spectre réflexion, Reflection spectrum, Espectro reflexión, Spectrométrie réflexion, Reflection spectroscopy, TDS, Chiral modification, D-( — )-tartaric acid, Pd(111), Reflection-absorption infrared spectroscopy, and Temperature-programmed desorption

The adsorption of chiral D-( — )-tartaric acid is studied on a Pd(111) substrate using a combination of temperature-programmed desorption (TPD) and reflection-absorption infrared spectroscopy (RAIRS). It is found that reaction at room temperature occurs predominantly via deprotonation of the carboxylic acid groups. Bitartrate species form at ~300 K at low coverages while monotartrate species predominate at higher coverages since the removal of the second proton is inhibited by surface crowding. It also appears that the bitartrate can rehydrogenate on heating to reform some monotartrate species. The hydrogens deriving from the carboxylate group desorbs at ~315 K, and the mono- and bitartrate species are stable to ~390 K where they decompose to evolve hydrogen, carbon dioxide and some water. Carbon monoxide is also formed and evolves in a desorption-rate limited state at ~450 K. Biacidic, second-layer D-( — )-tartaric acid adsorbs at higher coverages and initially desorbs in a state at ~329 K shifting to higher temperatures as the second-layer coverage increases, indicative of attractive interactions between adsorbates. A decomposition intermediate is detected by dosing D-( —)-tartaric acid at Iow temperatures (~100 K) and heating to ~300 K or by dosing at ~300 K and heating to ~320 K. and is characterized by modes at ~1313, 1261, 1202 and 1116 cm-1 assigned to δCH modes and a νalcCO vibration suggesting that the intermediate may form by the removal of the - COO group.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Interface gaz-liquide et liquide-liquide, Gas-liquid interface and liquid-liquid interface, Interface solide-liquide, Solid-liquid interface, Propriété physicochimique, Physicochemical properties, Propiedad fisicoquímica, Article synthèse, Review, Artículo síntesis, Etalement, Spreading, Escalonamiento, Gel polymère, Polymer gels, Goutte, Drop, Gota, Interface gaz liquide, Gas liquid interface, Interfase gas líquido, Interface liquide liquide, Liquid liquid interface, Interfase líquido líquido, Interface liquide solide, Liquid solid interface, Interfase líquido sólido, Liquide, Liquid, Líquido, Tension superficielle, Surface tension, Tensión superficial, Liquid surfaces, Marangoni flow, and Self-motility

Surface tension gradients are at the origin of the self-motion and deformation of millimeter-sized floating objects. For (quasi-)non-deformable systems, like solids and gels, the motion-mode is mainly controlled by the shape of the object and by the way the surface active propellant is released on the surrounding surface. Two situations are reviewed In the first one, the propellant container is the propelled object itself, while in the second case the propellant is placed in a reservoir embarked on a manufactured float. The properties and efficiency of these solid systems are examined and compared for different geometries. They are also compared with the intriguing properties of self-motile liquid lenses/drops which present several additional abilities (spontaneous deformation to adapt their shape to the selected motion-mode, presence of complex fluid flows outside and inside the drops, partial break-ups...). Three mechanisms leading to spontaneous motility have been identified in the literature. Among them two are more largely exemplified in the following as they involve a contribution of the Marangoni driven spreading effect, leading to velocities on the cm/s scale. The main theoretical tools usually used for describing the motion and deformation of such self-propelled systems are also reviewed.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Etudes physiques et chimiques. Granulométrie. Phénomènes électrocinétiques, Physical and chemical studies. Granulometry. Electrokinetic phenomena, Article synthèse, Review, Artículo síntesis, Asymétrie, Asymmetry, Asimetría, Capsule, Cápsula, Déformation, Deformation, Deformación, Forme, Shape, Forma, Microcapsule, Microcápsula, Nombre Reynolds, Reynolds number, Número Reynolds, Application biomédicale, Biomedical application, Autopropulsion, Micronageur, Microswimmer, Active swimmers, Deformation properties, Microcapsules, Movement at low Reynolds number, and Shape asymmetry

The mimicry of natural microswimmers by artificial nano- and micro-devices is extremely challenging because it is hard to achieve and control nanoscale actuation reproducibly and reversibly. In the context of recent developments, we shall review the basic phenomena of artificial swimming objects in the micrometer scale. Typically, these swimming devices were rigid, and up to now, the mechanisms of self-propulsion have only rarely been adapted to soft particles as microcapsules. The high flexibility of capsules is an important feature for more realistic descriptions of the basic swimming processes of biological cells. Additionally, micro- and nanocapsules show the advantage that they can store a defined amount of chemical or biological compounds in their core regions. This offers a high potential for the realization of diverse biological or medical applications (e.g. cargo transport and controlled drug delivery). The discussed phenomena are based on different chemical reactions or flow and diffusion principles, including bulk- and surface rheology, and they can be used to develop new ideas concerning the construction of advanced types of self-propelling microcapsules.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Emulsions. Microémulsions. Mousses, Emulsions. Microemulsions. Foams, Article synthèse, Review, Artículo síntesis, Cisaillement, Shear, Cizalladura, Couche interfaciale, Interfacial layer, Capa interfacial, Emulsion, Emulsión, Interface, Interfase, Mousse (émulsion), Foam, Espuma, Propriété dynamique, Dynamic properties, Propiedad dinámica, Rhéologie, Rheology, Reología, Bulk rheology of emulsion and foams, Dynamic interfacial properties, Interfacial dilational rheology, and Interfacial shear rheology

Dilational and shear viscoelasticities are important properties of interfacial layers. These quantities are particularly relevant in all systems which contain a huge internal interfacial area such as foams and emulsions. Therefore, also the 3D rheological behavior of foams or emulsions studied by respective methods is superimposed by the 2D interfacial rheology. We report on recent developments in dilational and shear rheology from an experimental point of view as well as discuss the state of the art of the underlying theories. Examples of most relevant experiments are also presented and discussed. Although not yet extensively investigated, the links between bulk rheology of foams and emulsions and the rheology of the corresponding interfacial layers are discussed. .

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Emulsions. Microémulsions. Mousses, Emulsions. Microemulsions. Foams, Article synthèse, Review, Artículo síntesis, Cisaillement, Shear, Cizalladura, Emulsion, Emulsión, Mousse (émulsion), Foam, Espuma, Rhéologie, Rheology, Reología, Emulsions, Foams, Shear-banding, Wall slip, and Yielding

We review the state of the art in foam and highly concentrated emulsion rheology, with an emphasis on progress made over the last five years. Since the structures and physico-chemical processes relevant for foams and emulsions are closely analogous, comparing the knowledge recently gained in these two neighboring fields brings fresh insight. In this spirit, we review how the macroscopic mechanical response arises from a coupling between interfacial energy and long range molecular interactions, entropic effects, interfacial rheology, and dynamics at the droplet or bubble scale. We present experiments and models concerning elasticity, osmotic pressure, yielding and flow behavior.

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Etat colloïdal et états dispersés, Colloidal state and disperse state, Micelles. Lames minces, Micelles. Thin films, Propriété rhéologique, Rheological properties, Propiedad reológica, Agent surface, Surfactant, Agente superficie, Article synthèse, Review, Artículo síntesis, Autoassemblage, Self assembly, Autoensamble, Micelle vermiculaire, Wormlike micelle, Micela elongada, Ramification, Branching, Ramificación, Rhéologie, Rheology, Reología, Viscoélasticité, Viscoelasticity, Viscoelasticidad, Self-assembled, and Wormlike micelles

The topology of self-assembled surfactant solutions includes varying degrees of micellar branching, ranging from linear wormlike micelles to a micellar network. Micellar branching acts as an effective attraction between micelles such that network condensation can lead to phase separation. Unlike chemical branching in polymers, micellar branches are labile. Movement of branches along a micelle contour has therefore been proposed as a mechanism of stress relaxation that leads to a reduction in the structural relaxation time and thus, the zero-shear viscosity. Branching is also thought to suppress flow alignment, and for lower levels of branching, may also suppress instabilities such as shear banding. The suppression of shear banding can lead to a lesser degree of shear-thinning in the apparent viscosity at higher shear rates, as well as a reduction in extensional thickening. However, for higher levels of branching, shear can induce branching for samples in proximity to such a phase transition, which can result in shear banding due to shear-induced phase separation. Recent modeling and simulations of the energetics of branching, as well as experiments on model systems, show that the reduction in zero-shear viscosity is due to micelle branching. Current research includes efforts to develop a more mechanistic, quantitative understanding of micellar branching and more generally, its effects on micellar solution rheology. .

Biochemistry, molecular biology, biophysics, Biochimie, biologie moléculaire, biophysique, General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Physicochimie de surface, Surface physical chemistry, Agents de surface: propriétés, Surface-active agents: properties, Etat colloïdal et états dispersés, Colloidal state and disperse state, Emulsions. Microémulsions. Mousses, Emulsions. Microemulsions. Foams, Acide gras, Fatty acids, Acido graso, Agent surface anionique, Anionic surfactant, Agente superficie aniónico, Article synthèse, Review, Artículo síntesis, Assemblage moléculaire, Molecular assembly, Ensamble molecular, Autoassemblage, Self assembly, Autoensamble, Interface, Interfase, Mousse (émulsion), Foam, Espuma, Rhéologie, Rheology, Reología, Fatty acid, Responsive surfactant, and Self-assembly

Fatty acids are anionic surfactants under their deprotonated forms. They are surfactants with both biodegrability and low toxicity. Fatty add molecules can self-assemble under various shapes in an aqueous solution. These self-assembled structures can respond to stimuli such as pH, CO2 and temperature due to changes occurring at the molecular level. These specificities make them surfactants of special interest to tune the properties at a macroscopic scale. The aim of this article is to review the recent advances in the creation and in the understanding of responsive self-assemblies obtained from fatty acid molecules in an aqueous solution. The links between the microscopic, mesoscopic and macroscopic scales are described. The alkyl chain melting phenomenon triggered by temperature at the molecular level leading to thermoresponsive interfaces and foams at the macroscopic scale is highlighted.

General chemistry, physical chemistry, Chimie générale, chimie physique, Nanotechnologies, nanostructures, nanoobjects, Nanotechnologies, nanostructures, nanoobjets, Condensed state physics, Physique de l'état condensé, Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Etat condense: structure, proprietes mecaniques et thermiques, Condensed matter: structure, mechanical and thermal properties, Etat condense: structure electronique, proprietes electriques, magnetiques et optiques, Condensed matter: electronic structure, electrical, magnetic, and optical properties, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Enantiosélectivité, Enantioselectivity, Enantioselectividad, Nanoparticule, Nanoparticles, Rotation polarisation optique, Optical rotation, Adsorption, Chiral, and Propylene oxide

Au nanoparticles modified with enantiomerically pure D- or L-cysteine have been shown to serve as enantioselective adsorbents of R- and S-propylene oxide. A simple adsorption model and accompanying experimental protocol have been developed to enable optical rotation measurements to be analyzed for quantitative determination of the ratios of the enantiospecific adsorption equilibrium constants of chiral species on the surfaces of chiral nanoparticles, KSL/KSD = KRD/KRL. This analysis is robust in the sense that it obviates the need to measure the absolute surface area of the absorbent nanoparticles, a quantity that is somewhat difficult to obtain accurately. This analysis has been applied to optical rotation data obtained from solutions of R- and S-propylene oxide, in varying concentration ratios, with D- and L-cysteine coated Au nanoparticles, in varying concentration ratios.