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Univ. Paris-Saclay
17 octobre 2022
I. Mirebeau et N. Martin, J. Appl. Cryst. (2022). 55, 1173-1183 The application is discussed of neutron methods to the study of reentrant spin glasses (RSGs), close to the transition towards a `canonical' spin glass (SG). The focus is on two emblematic systems, namely Au1−xFex and amorphous a-Fe1−xMnx. A set of experimental results is presented to highlight their peculiar static and dynamic properties.
02 septembre 2022
Simeon Minić, Burkhard Annighöfer, Arnaud Hélary, Laïla Sago, David Cornu, Annie Brûlet, Sophie Combet High pressure (HP) is a particularly powerful tool to study protein folding/unfolding, revealing subtle structural rearrangements. Bovine β-lactoglobulin (BLG), a protein of interest in food science, exhibits a strong propensity to bind various bioactive molecules.
01 juillet 2022
Tiago Outerelo Corvo, Antoine Jourdain, Shona O’Brien, Frédéric Restagno, Eric Drockenmuller, and Alexis Chennevière Poly(ionic liquid)s (PILs), similar to their ionic liquid (IL) analogues, present a nanostructure arising from local interactions.
02 juin 2022
Marion Grzelka, Iurii Antoniuk, Éric Drockenmuller, Alexis Chennevière, Liliane Léger, and Frédéric Restagno The role of the polymer volume fraction, ϕ, on steady-state slippage and interfacial friction is investigated for semi-dilute polystyrene solutions in diethyl phthalate in contact with two solid surfaces. Significant slippage is evidenced for all samples, with slip lengths b obeying a power law dependence.
21 avril 2022
Sumit Mehan, Laure Herrmann, Jean-Paul Chapel, Jacques Jestin, Jean-Francois Berret and Fabrice Cousin We investigate the formation/re-dissociation mechanisms of hybrid complexes made from negatively charged PAA2k coated g-Fe2O3 nanoparticles (NP) and positively charged polycations (PDADMAC) in aqueous solution in the regime of very high ionic strength (I).
22 février 2022
J.C.Riedl, M.Sarkar, T.Fiuza, F.Cousin, J.Depeyrot, E.Dubois,G.Mériguet,R.Perzynski and V.Peyre Some of the most promising fields of application of ionic liquid-based colloids imply elevated temperatures. Their careful design and analysis is therefore essential. We assume that tuning the structure of the nanoparticle-ionic liquid interface through its composition can ensure colloidal stability for a wide temperature range, from room temperature up to 200 °C. https://doi.org/10.
15 décembre 2021
Virginie Vergnat, Benoît Heinrich, Michel Rawiso, René Muller, Geneviève Pourroy and Patrick Masson Embedding nanoparticles (NPs) with organic shells is a way to control their aggregation behavior. Using polymers allows reaching relatively high shell thicknesses but suffers from the difficulty of obtaining regular hybrid objects at gram scale.
18 septembre 2021
T. Fiuza, M. Sarkar, J. C. Riedl, A. Cebers, F. Cousin, G. Demouchy, J. Depeyrot, E. Dubois, F. Gelebart, G. Meriguet, R. Perzynski and V. Peyre Ferrofluids based on maghemite nanoparticles (NPs), typically 10 nm in diameter, are dispersed in an ionic liquid (1-ethyl 3-methylimidazolium bistriflimide – EMIM-TFSI). The average interparticle interaction is found to be repulsive by small angle scattering of X-rays and of neutrons, with a second virial coefficient A2 = 7.3.
21 juillet 2021
Sebastian Jaksch, Alexis Chennevière, Sylvain Désert, Tadeusz Kozielewski, Herbert Feilbach, Pascal Lavie, Romuald Hanslik, Achim Gussen, Stephan Butterweck, Ralf Engels, Henrich Frielinghaus, Stephan Förster and Peter Müller-Buschbaum Small-K Advanced DIffractometer (SKADI is a Small-Angle Neutron Scattering (SANS) instrument to be constructed at the European Spallation Source (ESS).
02 décembre 2020
Simeon Minic, Burkhard Annighofer, Arnaud Helary, Djemel Hamdane, Gaston Hui Bon Hoa, Camille Loupiac, Annie Brulet, and Sophie Combet To probe intermediate states during unfolding and oligomerization of proteins remains a major challenge. High pressure (HP) is a powerful tool for studying these problems, revealing subtle structural changes in proteins not accessible by other means of denaturation.
10 novembre 2020
Chang Liu, Wenxian Hu, Hanqiu Jiang, Guoming Liu*, Charles C. Han, Henning Sirringhaus, François Boué, and Dujin Wang The determination of intrinsic chain stiffness of conjugated polymers is challenging, in particular, for scattering techniques because of their strong light absorption and structural instability due to the complicated intra-/intermolecular interactions.
28 septembre 2020
Li Shi, Florent Carn, Arsen Goukassov, Eric Buhler, and François Boué Mixing negatively charged polyelectrolyte (PEL) with positively charged gold nanoparticles (Au NPs) in aqueous solution results in electrostatics complexes of different shapes and compactness. Here, when complexing with a semirigid PEL hyaluronic acid (HA), we obtain crystals made of nanoparticles in a new region of the phase diagram, as evidenced by small-angle Xray scattering (SAXS).
02 septembre 2020
Marine Le Goas, Tom Roussel, Maria Kalbazova, David Carrière, Elodie Barruet, Valerie Geertsen, Giulia C. Fadda, Fabienne Testard, Geraldine Carrot and Jean-Philippe Renault Nanomedicines are considered as promising therapeutics for cancer treatment. However, clinical translation is still scarce, partly because their biological behavior is not well understood.
23 juin 2020
We show by X-ray and neutron small-angle scattering that gold nanoparticles with controlled sizes and morphologies can be obtained by the metallic reduction of AuCl4– ions trapped in 3D organic molds by X-ray radiolysis. The molds are spherical frozen micelles of polystyrene-b-poly(dimethylaminoethyl methacrylate) (PS-b-PDMAEMA) block copolymer in acidic aqueous solution with a PS spherical core surrounded by a corona of PDMAEMA chains in good solvent.
09 mai 2020
Andrew M. Jimenez, Dan Zhao, Kyle Misquitta, Jacques Jestin and Sanat K. Kumar Understanding the structure and dynamics of the bound polymer layer (BL) that forms on favorably interacting nanoparticles (NPs) is critical to revealing the mechanisms responsible for material property enhancements in polymer nanocomposites (PNCs).
08 avril 2020
Aline Maire du Poset, Mikaela Börjesson, Céline Rameau, Claire Madeleine-Perdrillat, Adrien Lerbret, Camille Loupiac, Fabrice Cousin, Ali Assifaoui We show here how the structure of polygalacturonate (polyGalA) hydrogels cross-linked by Ca2+ cations via external gelation controls the loading and release rate of beta-lactoglobulin (BLG), a globular protein.
13 février 2020
de Oliveira-Silva, Rodrigo; Bélime, Agathe; Le Coeur, Clémence; Chennevière, Alexis; Helary, Arnaud; Cousin, Fabrice; Judeinstein, Patrick; Sakellariou, Dimitrios; Zanotti, Jean-Marc In soft condensed matter, Small Angle Neutron Scattering (SANS) is a central tool to probe structures with characteristic sizes ranging from 1 to 100 nm. However, when used as a standalone technique, the dynamic properties of the sample are not accessible.
25 novembre 2019
A. S. Sukhanov, Praveen Vir, A. S. Cameron, H. C. Wu, N. Martin, S. Mühlbauer, A. Heinemann, H. D. Yang, C. Felser, and D. S. Inosov The cubic chiral helimagnets with the P213 space group represent a group of compounds in which the stable skyrmion-lattice state is experimentally observed. The key parameter that controls the energy landscape of such systems and determines the emergence of a topologically nontrivial magnetic structure is the Dzyaloshinskii-Moriya interaction (DMI).
20 juin 2019
A. Theodoratou, L.-T. Lee, J. Oberdisse and A. Aubert-Pouëssel, Langmuir 35(20) (2019) 6620. Abstract : Nanofilms of about 2 nm thickness have been formed at the air–water interface using functionalized castor oil (ICO) with cross-linkable silylated groups.
04 mai 2019
B. Annighöfer , A. Hélary, A. Brulet, A. Colas de la Noue, C. Loupiac and S. Combet Review of Scientific Instruments 90 (2019) 025106 Abstract : We report on a high pressure (HP) cell designed for the determination of the structure of molecular solutions by small-angle neutron scattering (SANS). The HP cell is fitted up with two thick metallic windows that make the device very resistant under hydrostatic pressures up to 600 MPa (or 6 kbar).
05 mars 2019
Annelies Sels, Giovanni Salassa, Fabrice Cousin, Lay-Theng Lee, Thomas Bürgi, Nanoscale 26 (2018) 12754. Aromatic dithiol linkers were used to prepare aggregates of Au25(SR)18 clusters (SR: thiolate) via ligand exchange reactions. Fractions of different aggregate sizes were separated by size exclusion chromatography (SEC).
04 mars 2019
Marguerite Léang, Didier Lairez, Fabrice Cousin, Frédérique Giorgiutti-Dauphiné, Ludovic Pauchard, Lay-Theng Lee During evaporative drying of a colloidal dispersion, the structural behavior at the air-dispersion interface is of particular relevance to the understanding of the consolidation mechanism and the final structural and mechanical properties of the porous media.
15 février 2019
Burkhard Annighöfer, Arnaud Hélary, Annie Brûlet, Alexandre Colas de la Noue, Camille Loupiac, and Sophie Combet We report on a high pressure (HP) cell designed for the determination of the structure of molecular solutions by small-angle neutron scattering (SANS). The HP cell is fitted up with two thick metallic windows that make the device very resistant under hydrostatic pressures up to 600 MPa (or 6 kbar).
12 décembre 2018
Souha Ben Mahmoud, Wafa Essafi, Annie Brûlet and François Boué The chain conformation in sulfonated polystyrene PSSNa of a degree of sulfonation 0.34 ≤ f ≤ 1, i.e., of various hydrophobicity, is followed in mixtures of water and increasing content of tetrahydrofuran (THF), a good solvent of the hydrophobic polystyrene moieties (which improves the solvent quality of the mixture).
20 novembre 2018
Jyotsana Lal This article is dedicated to the memory of Loic Auvray The results on Winsor phases, droplet and bicontinous microemulsions phases with polymer-grafted lipids studied by Small Angle Neutron Scattering (SANS) are reported below, together with the contrast variation techniques used to characterize the average curvature in the system.
15 octobre 2018
Raphael Dos Santos Morais, Olivier Delalande, Javier Perez, Dominique Mias-Lucquin, Melanie Lagarrigue, Anne Martel, Anne-Elisabeth Molza, Angelique Cheron, Celine Raguenes-Nicol, Thomas Chenuel, Arnaud Bondon, Marie-Sousai Appavou, Elisabeth Le Rumeur, Sophie Combet, and Jean-Francois Hubert Scaffolding proteins play important roles in supporting the plasma membrane (sarcolemma) of muscle cells.
24 septembre 2018
Fengjiao Qian, Lars J. Bannenberg, Heribert Wilhelm, Grégory Chaboussant, Lisa M. Debeer-Schmitt, Marcus P. Schmidt, Aisha Aqeel, Thomas T. M. Palstra, Ekkes Brück, Anton J. E. Lefering, Catherine Pappas, Maxim Mostovoy, Andrey O.
29 août 2018
I. Mirebeau, N. Martin, M. Deutsch, L. J. Bannenberg, C. Pappas, G. Chaboussant, R. Cubitt, C. Decorse, and A. O. Leonov Reentrant spin glasses are frustrated disordered ferromagnets developing vortexlike textures under an applied magnetic field. Our study of a Ni0.81Mn0.19Ni0.81Mn0.19 single crystal by small angle neutron scattering clarifies their internal structure and shows that these textures are randomly distributed.
09 août 2018
Maelenn Chevreuil, Didier Law-Hine, Jingzhi Chen, Stéphane Bressanelli, Sophie Combet, Doru Constantin, Jéril Degrouard, Johannes Möller, Mehdi Zeghal and Guillaume Tresset The survival of viruses partly relies on their ability to self-assemble inside host cells. Although coarse-grained simulations have identified different pathways leading to assembled virions from their components, experimental evidence is severely lacking.
17 avril 2018
We report on the self-assembly behavior of poly(2-methyl-2-oxazoline)–block–poly(2-octyl-2-oxazoline) comprising different terminal perfluoroalkyl fragments in aqueous solutions. As reported previously [Kaberov et al. (2017)] such polyphiles can form a plethora of nanostructures depending of the composition and on the way of preparation.
26 octobre 2017
Raphael Dos Santos Morais, Olivier Delalande, Javier Pérez, Liza Mouret, Arnaud Bondon, Anne Martel, Marie-Sousai Appavou, Elisabeth Le Rumeur, Jean-François Hubert, and Sophie Combet Obtaining structural information on integral or peripheral membrane proteins is currently arduous due to the difficulty of their solubilization, purification, and crystallization (for X-ray crystallography (XRC) application).

 

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