A5062417449- Polymer Nanocomposites and Properties
- Hydrogels: synthesis, properties, applications
- Polymer crystallization and properties
- Advanced Cellulose Research Studies
- Supramolecular Self-Assembly in Materials
- Polymer Surface Interaction Studies
- Material Dynamics and Properties
- Mesoporous Materials and Catalysis
- Electrostatics and Colloid Interactions
- Nanocomposite Films for Food Packaging
- Catalytic Processes in Materials Science
- Surfactants and Colloidal Systems
- Lipid Membrane Structure and Behavior
- Polydiacetylene-based materials and applications
- Lignin and Wood Chemistry
- Nanoparticle-Based Drug Delivery
- Phase Equilibria and Thermodynamics
- Fusion materials and technologies
- Force Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Rheology and Fluid Dynamics Studies
- Advanced Sensor and Energy Harvesting Materials
- Microstructure and Mechanical Properties of Steels
- Non-Destructive Testing Techniques
- Advanced Polymer Synthesis and Characterization
Université Grenoble Alpes
2014-2024
Centre National de la Recherche Scientifique
2013-2024
Laboratoire Interdisciplinaire de Physique
2012-2023
Université Joseph Fourier
2003-2011
Instituto de Ciencia y Tecnología de Polímeros
2007-2009
University of Brighton
2009
Lund University
2007-2009
Science et Ingénierie des Matériaux et Procédés
2007-2009
McGill University
2009
Leibniz Institute of Polymer Research
2009
Abstract Wood and other cellulosic materials are highly sensitive to changes in moisture content, which affects their use most applications. We investigated the effects of on nanoscale structure wood using X-ray neutron scattering, complemented by dynamic vapor sorption. The studied set samples included tension normal hardwood as well representatives two softwood species. Their nanostructure was characterized wet state before after first drying at relative humidities between 15 90%....
In this work, we propose the formation of stretchable hydrogels at neutral pH from physical crosslinking chitosan (CS) and hyaluronic acid (HA) by polyelectrolyte complexation. A mixture CS (M
The controlled complex coacervation of oppositely charged hyaluronic acid (Mw ≈ 800-1000 kg mol-1) and chitosan 160 mol-1, degree acetylation = 15%) led to hydrogels with controllable properties in terms elasticity strength. In this work, we performed desalting by dialysis high ionic strength solutions mixed polyelectrolytes showed that the control pH during polyelectrolyte assembly greatly impacts mechanical hydrogel. First, for pHs from 5.5 7.5, a slight was observed due low protonation...
Macroporous poly(N-isopropylacrylamide) (pNIPA) gels (so-called cryogels), cross-linked with different bis-acrylic compounds, N,N′-methylenebisacrylamide (MBAAm) and dimethacrylate-tyrosine-lysine-tyrosine (DMTLT), were prepared through free-radical polymerization at subzero temperature in dioxane/water media. DMTLT is a hydrolytically degradable cross-linker relatively hydrophobic character. The effects of synthesis conditions, namely the concentration monomers, cross-linker, initiator...
This study describes biosourced binary materials which synergize the attributes of guar gum, a vegetal galactomannan, with ones deep eutectic solvents (DES). The preparation library DES, stemming from H-bonding complexation renewable molecules such as choline chloride (ChCl) urea, di or triacids, polyols, carbohydrates was confirmed by thermal analysis, WAXS morphology, and viscosity study. Interestingly, gum develops favorable polar interactions (mainly H-bonds) most these leading to...
The use of two techniques, differential interferometry and quasi-elastic light scattering (QELS), allowed us to study solutions chitosan varying in degree acetylation (DA), dissociation (α), concentration (Cp). With the first technique, we demonstrated modification electric polarizability polymer chains, through a law behavior variation refractive index increment dn/dC with DA α. This brought information on various kinds interactions (H-bonds, electrostatic, hydrophobic) involved evolution...
The temperature-induced structural modifications of poly(N-isopropylacrylamide) hydrogel (pNIPA) were investigated by small-angle X-ray scattering (SAXS) over a broad range q values (3.5 × 10−2−12 nm−1) at temperatures ranging between 18 and 37 °C. sample studied was elaborated cryopolymerization yielding macroporous gel (cryogel). pNIPA forms the walls (the thickness 23 °C is about 12 μm). SAXS curves display an isoscattering (or isosbestic) point located qiso = 3.633 nm−1 disappearing...
The complexity of the mechanical behavior filled elastomers can be partly attributed to fact that duration an applied strain plays a crucial role. In order bring new insights into this still incompletely solved problem, we look for relationships between macroscopic relaxation and filler particles at nano- mesoscale. To end, X-ray photon correlation spectroscopy (XPCS) in homodyne heterodyne configurations combined with tensile stress is employed. paper devoted study role filler–filler...
A variety of activated carbons (ACs) with different burnoff degrees (0–60%) and polystyrene cross-linked divinylbenzene (PSDVB) were studied using small-angle X-ray scattering (SAXS) nitrogen adsorption methods. The ACs demonstrate increased deviation the pore shape from model slit-shaped pores increasing degree parallel contributions in 0.3–50 nm range. size distributions (PSDs) calculated SAXS density functional theory (DFT) methods have similar shapes but a more detailed picture for broad...
Chitosan-coated surfaces are of great interest for biomedical applications (antibacterial coatings, implants, would healing, single-cell microfluidics…). However, one major limitation chitosan-based systems is the high solubility polymer under acidic aqueous conditions. Herein, we describe a simple procedure to prepare extremely smooth and stable chitosan coatings. In detail, films with low degree N-acetylation thicknesses varying from 40 nm 10 μm were grafted onto epoxy-functionalized...
Abstract Elastomers are soft materials that can be reinforced by dispersing into them nanosized solid particles. Common examples of the latter silica or carbon black aggregates. However, mechanism reinforcement is still not yet fully understood. Our work consists in investigating small‐angle X‐ray scattering (SAXS) structure aggregate network spreading throughout matrix initial sample and its modification during after straining (elongation). The goal to relate macroscopic mechanical...
An emerging target to overcome cancer resistance treatments is copper, which upregulated in a wide variety of tumors and may be associated with progression metastases. The aim this study was develop multimodal ultrasmall nanoparticle, CuPRiX, based on the clinical AGuIX nanoparticle made polysiloxane matrix gadolinium chelates are grafted. Such hybrid nanoparticles allow: (i) localized depletion copper prevent tumor cell dissemination metastasis formation (ii) an increased sensitivity...
Two-photon fluorescence microscopy (TPFM) usually used to get 3-D pictures of biological systems has been applied here for the first time macroporous hydrogels prepared by cryogelation ("cryogels"). Unlike environmental scanning electron (ESEM) which analyzes surface swollen samples, TPFM delivers images successive planes in depth material allowing a imaging its structure. The studied were poly(N-isopropylacrylamide) (pNIPA), poly(hydroxyethyl methacrylate-l-lactide-dextran) (pHEMA-LLA-D)...
ABSTRACT Tensile stress‐relaxation measurements have been performed on a series of cross‐linked filled elastomers. The fillers are chosen to investigate the effect filler–filler and filler–matrix interactions time dependence tensile relaxation modulus E(t) after UP DOWN jumps. For carbon black‐filled sample (strong filler–elastomer interaction) decreases as log( t ) when strain ε is strictly larger than 0.2 reached by silica‐filled samples in same conditions, for all jump, including = 0.2,...
Fe3O4 nanoparticles coated with chito-oligosaccharides (COS) were prepared in situ by a simple co-precipitation method through mixing of iron ions (Fe3+ and Fe2+) COS aqueous solutions followed precipitation ammonia. The impact different degree polymerization (DP 10, 24 45) N-acetylation (DA) ∼ 24% 50% (exhibiting high solubility) on the synthesis physical properties magnetic was evaluated. Several advantages found when presence studied COS, such as: preparation functionalized narrower size...
We show by X-ray and neutron small-angle scattering that gold nanoparticles with controlled sizes morphologies can be obtained the metallic reduction of AuCl4– ions trapped in 3D organic molds radiolysis. The are spherical frozen micelles polystyrene-b-poly(dimethylaminoethyl methacrylate) (PS-b-PDMAEMA) block copolymer acidic aqueous solution a PS core surrounded corona PDMAEMA chains good solvent. behavior is [AuCl4–]/[DMAEMA] ratio RAuCl4–/DMAEMA. At low concentration, condense on...
Amylose, a mostly linear homopolymer of glucosyl units extracted from native starch granules, can form large variety so-called V-type host–guest complexes when cocrystallized with small hydrophobic molecules. Several allomorphs are known that contain six-, seven-, or eight-fold amylose single helices, the guest molecules being located in in-between, both. The present report describes crystal structure model lamellar inclusion prepared by crystallizing dilute aqueous solutions presence three...
Abstract Hydrothermal treatment between 150 °C and 230 is widely used in wood processing, from the steam of timber for better dimensional stability durability to pretreatment enzymatic saccharification chemical pulping. Understanding ultrastructural changes cell walls through hydrothermal treatments crucial controlling optimizing these treatment-based processes. Here, we studied ultrastructure 24 hardwood species using simultaneous small- wide-angle X-ray scattering measurements before after...