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Production scientifique
Matière Molle
(422) Articles dans des revues
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Direct Photomodification of Polymer Surfaces: Unleashing the Potential of Aryl-Azide Copolymers
Auteur(s): Schulz Anita, Stocco A., Bethry Audrey, Lavigne Jean-Philippe, Coudane Jean, Nottelet Benjamin
(Article) Publié:
Advanced Functional Materials, vol. 28 p.1800976 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01909547_v1
DOI: 10.1002/adfm.201800976
WoS: 000439738200010
Exporter : BibTex | endNote
6 Citations
Résumé: The possibility to impart surface properties to any polymeric substrate using a fast, reproducible, and industrially friendly procedure, without the need for surface pretreatment, is highly sought after. This is in particular true in the frame of antibacterial surfaces to hinder the threat of biofilm formation. In this study, the potential of aryl‐azide polymers for photofunctionalization and the importance of the polymer structure for an efficient grafting are demonstrated. The strategy is illustrated with a UV‐reactive hydrophilic poly(2‐oxazoline) based copolymer, which can be photografted onto any polymer substrate that contains carbon–hydrogen bonds to introduce antifouling properties. Through detailed characterization it is demonstrated that the controlled spatial distribution of the UV‐reactive aryl‐azide moieties within the poly(2‐oxazline) structure, in the form of pseudogradient copolymers, ensures higher grafting efficacy than other copolymer structures including block copolymers. Furthermore, it is found that the photografting results in a covalently bound layer, which is thermally stable and causes a significant antiadherence effect and biofilm reduction against Escherichia coli and Staphylococcus epidermidis strains while remaining noncytotoxic against mouse fibroblasts.
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Van der Waals Emulsions: Emulsions Stabilized by Surface-Inactive, Hydrophilic Particles via van der Waals Attraction
Auteur(s): Marina Paula Facal, Cheng Chongling, Sedev Rossen, Stocco A., Binks Bernard, Wang Dayang
(Article) Publié:
Angewandte Chemie International Edition, vol. 57 p.9510 - 9514 (2018)
Texte intégral en Openaccess :
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Methods for Screening Cloud Point Temperatures
Auteur(s): Pincemaille J., Banc A., Chauveau E., Fromental J.-M., Ramos L., Morel Marie-Hélène, Menut P.
(Article) Publié:
Food Biophysics, vol. 13 p.422-431 (2018)
Ref HAL: hal-01908982_v1
DOI: 10.1007/s11483-018-9548-1
WoS: WOS:000448509200010
Exporter : BibTex | endNote
4 Citations
Résumé: A novel and simple method for the measurement of cloud point temperatures of solutions is presented. Cloud point determination , which is currently used to establish the phase diagrams of protein solutions, is indicative of proteins interactions and constitutes a useful tool for food products engineering. We describe a novel experimental setup that allows screening of a large number of physical-chemical conditions in one measurement and the determination of cloud point temperatures both above and below ambient temperature. We use a simple method to avoid solvent evaporation and condensation, so that the setup can be used for solutions prepared with a volatile solvent. We present the operating parameter range and the precision of the measurement. The optical properties of the system are calibrated with solutions of known transmittance, and the determination of cloud point temperatures is validated on a standard non-ionic surfactant solution. Finally, we demonstrate the efficiency of the method by determining the phase diagram of a wheat protein extract, soluble in a water/ethanol mixture. Complemented with differential scanning calorimetry measurements, the liquid-liquid phase transition can be determined up to a protein concentration of 250 g/L, a range inaccessible with conventional methods for this protein extract.
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Quenched disorder of a nematic liquid crystal under a magnetic field
Auteur(s): Slyusarenko Kostyantyn, Blanc C., Reznikov Yuriy, Nobili M.
(Article) Publié:
Journal Of Molecular Liquids, vol. 267 p.100 - 108 (2018)
Ref HAL: hal-01906564_v1
DOI: 10.1016/j.molliq.2018.02.055
WoS: 000447575800015
Exporter : BibTex | endNote
2 Citations
Résumé: We report measurements and theoretical predictions on the effect of an aligning magnetic field on the orientational disorder of a nematic liquid crystal in contact with isotropic solid substrates. Different types of substrates present a similar disorder and a similar dependency on the magnetic field amplitude, i.e. a decreasing of the angular distribution widths and spatial correlation lengths. Measurements are in qualitative agreement with a theory where the orientational disorder emerges from the competition between the aligning magnetic torque and the disorienting thermal fluctuations during the adsorption of the liquid crystal molecules on the substrate.
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A wheat grain quantitative evaluation of vitreousness by light transmission analysis
Auteur(s): Chichti Emna, Carrère Myriam, George M., Delenne Jean-Yves, Lullien-Pellerin Valerie
(Article) Publié:
Journal Of Cereal Science, vol. 83 p.58 - 62 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01904339_v1
DOI: 10.1016/j.jcs.2018.07.009
WoS: 000448494900008
Exporter : BibTex | endNote
3 Citations
Résumé: Light transmission through wheat (T. aestivum L.) grain longitudinal cross sections of different thickness was used to study the endosperm microstructure and was shown to strictly follow a Beer-Lambert law allowing a non ambiguous quantification of the endosperm vitreousness. Therefore similar samples obtained from near-isogenic lines differing by hardness and grown in two distinct environments affecting their vitreousness were analyzed and confirmed the relationship between light transmission and the endosperm microstructure. In each sample, moreover analysis of light transmission within the different grain parts highlighted the greater compactness of the central endosperm cheeks in comparison with the distal and the proximal regions. These results helps a better understanding of the endosperm microstructure.
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Microscopic dynamics and failure precursors of a gel under mechanical load
Auteur(s): Aime S., Ramos L., Cipelletti L.
(Article) Publié:
Proceedings Of The National Academy Of Sciences Of The United States Of America, vol. 115 p.3587 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01904079_v1
Ref Arxiv: 1804.01810
DOI: 10.1073/pnas.1717403115
WoS: 000429012500051
Ref. & Cit.: NASA ADS
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19 Citations
Résumé: Material failure is ubiquitous, with implications from geology to everyday life and material science. It often involves sudden, unpredictable events, with little or no macroscopically detectable precursors. A deeper understanding of the microscopic mechanisms eventually leading to failure is clearly required, but experiments remain scarce. Here, we show that the microscopic dynamics of a colloidal gel, a model network-forming system, exhibit dramatic changes that precede its macroscopic failure by thousands of seconds. Using an original setup coupling light scattering and rheology, we simultaneously measure the macroscopic deformation and the microscopic dynamics of the gel, while applying a constant shear stress. We show that the network failure is preceded by qualitative and quantitative changes of the dynamics, from reversible particle displacements to a burst of irreversible plastic rearrangements.
Commentaires: . Réf Journal: PNAS 115, 3587 (2018)
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Nano-porous structures via self-assembly of amphiphilic triblock copolymers: influence of solvent and molecular weight
Auteur(s): Nehache Sabrina, Semsarilar M., In M., Dieudonne-George P., Lai Kee Him J., Bron P., Quemener D.
(Article) Publié:
Journal Of Polymer Science Part A: Polymer Chemistry, vol. 9 p.193-202 (2018)
Ref HAL: hal-01680368_v1
DOI: 10.1039/c7py01853c
WoS: 000418645100006
Exporter : BibTex | endNote
4 Citations
Résumé: Control of film structures made from a polystyrene-polystyrene sodium sulfonate-polystyrene (PS-PNaSS-PS) copolymer micellar solution is investigated in a THF/water mixture. Four different copolymers (varying molecular weights) are synthesised via RAFT (Reversible Addition Fragmentation chain Transfer) polymerisation. Depending on parameters such as copolymer molecular weight, solvent composition and copolymer concentration, the PS-PNaSS-PS triblock self-assembles into different morphologies in solution and dry state. The effect of each parameter is investigated using characterization techniques such as AFM, TEM, Cryo-TEM, SEM and SAXS. The morphologies obtained for PS-PNaSS-PS are found to be extremely sensitive when the water content of the micellar solution is low. Among the structures observed, a highly ordered nano-porous film is obtained using a PS10k-PNaSS6k-PS10k triblock copolymer solution containing 3.0 wt% of water. This micellar solution is used to prepare a porous membrane for filtration applications. Pure water filtration data suggest a pore size in the range of ultrafiltration, making these membranes attractive for applications in the food industry, for bacteria, virus and protein removal.
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