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Production scientifique
Matière Molle
(422) Articles dans des revues
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Overcharging and reentrant condensation of thermoresponsive ionic microgels
Auteur(s): Truzzolillo D., Sennato Simona, Sarti Stefano, Casciardi Stefano, Bazzoni Chiara, Bordi Federico
(Article) Publié:
Soft Matter, vol. 14 p.4110 - 4125 (2018)
Texte intégral en Openaccess :
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Multistep building of a soft plant protein film at the air-water interface
Auteur(s): Poirier A., Banc A., Stocco A., In M., Ramos L.
(Article) Publié:
Journal Of Colloid And Interface Science, vol. 526 p.337 - 346 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01788790_v1
PMID 29751267
DOI: 10.1016/j.jcis.2018.04.087
WoS: 000436900400034
Exporter : BibTex | endNote
20 Citations
Résumé: Gliadins are edible wheat storage proteins well known for their surface active properties. In this paper, we present experimental results on the interfacial properties of acidic solutions of gliadin studied over 5 decades of concentrations, from 0.001 to 110 g/L. Dynamic pendant drop tensiometry reveals that the surface pressure of gliadin solutions builds up in a multistep process. The series of curves of the time evolution of collected at different bulk protein concentrations C can be merged onto a single master curve when is plotted as a function of t where t is the time elapsed since the formation of the air/water interface and is a shift parameter that varies with C as a power law with an exponent 2. The existence of such time-concentration superposition, which we evidence for the first time, indicates that the same mechanisms govern the surface tension evolution at all concentrations and are accelerated by an increase of the bulk concentration. The scaling of with C is consistent with a kinetic of adsorption controlled by the diffusion of the proteins in the bulk. Moreover, we show that the proteins adsorption at the air/water interface is kinetically irreversible. Correlated evolutions of the optical and elastic properties of the interfaces, as probed by ellipsometry and surface dilatational rheology respectively, provide a consistent physical picture of the building up of the protein interfacial layer. A progressive coverage of the interface by the proteins occurs at low . This stage is followed, at higher , by conformational rearrangements of the protein film, which are identified by a strong increase of the dissipative viscoelastic properties of the film concomitantly with a peculiar evolution of its optical profile that we have rationalized. In the last stage, at even higher surface pressure, the adsorption is arrested; the optical profile is not modified while the elasticity of the interfacial layer dramatically increases with the surface pressure, presumably due to the film ageing.
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Aggregate Formation of Surface-Modified Nanoparticles in Solvents and Polymer Nanocomposites
Auteur(s): Musino D., Genix A.-C., Chaussee Thomas, Guy Laurent, Meissner Natalia, Kozak Radoslaw, Bizien Thomas, Oberdisse J.
(Article) Publié:
Langmuir, vol. 34 p.3010-3020 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01768107_v1
PMID 29443532
Ref Arxiv: 2007.15470
DOI: 10.1021/acs.langmuir.7b03932
WoS: WOS:000427095400012
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
9 Citations
Résumé: A new method based on the combination of small-anglescattering, reverse Monte Carlo simulations, and an aggregate recognition algorithm is proposed to characterize the structure of nanoparticle suspensions in solvents and polymer nanocomposites, allowing detailedstudies of the impact of different nanoparticle surface modifications.Experimental small-angle scattering is reproduced using simulated annealing of configurations of polydisperse particles in a simulation box compatible with the lowest experimental q-vector. Then, properties of interest likeaggregation states are extracted from these configurations and averaged. This approach has been applied to silane surface-modified silica nanoparticles with different grafting groups, in solvents and after casting into polymer matrices.It is shown that the chemistry of the silane function, in particular mono- or trifunctionality possibly related to patch formation, affects the dispersion state in a given medium, in spite of an unchanged alkylchain length. Our approach may be applied to study any dispersion or aggregation state of nanoparticles. Concerningnanocomposites, the method has potential impact on the design of new formulations allowing controlled tuning of nanoparticle dispersion.
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Impact of Beads and Drops on a Repellent Solid Surface: A Unified Description
Auteur(s): Arora S., Fromental J.-M., Mora S., Phou T., Ramos L., Ligoure C.
(Article) Publié:
Physical Review Letters, vol. 120 p.148003 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01761380_v1
DOI: 10.1103/PhysRevLett.120.148003
WoS: 000429451000016
Exporter : BibTex | endNote
5 Citations
Résumé: We investigate freely expanding sheets formed by ultrasoft gel beads, and liquid and viscoelastic drops, produced by the impact of the bead or drop on a silicon wafer covered with a thin layer of liquid nitrogen that suppresses viscous dissipation thanks to an inverse Leidenfrost effect. Our experiments show a unified behavior for the impact dynamics that holds for solids, liquids, and viscoelastic fluids and that we rationalize by properly taking into account elastocapillary effects. In this framework, the classical impact dynamics of solids and liquids, as far as viscous dissipation is negligible, appears as the asymptotic limits of a universal theoretical description. A novel material-dependent characteristic velocity that includes both capillary and bulk elasticity emerges from this unified description of the physics of impact.
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Role of spatial heterogeneity in the collective dynamics of cilia beating in a minimal one-dimensional model
Auteur(s): Dey S., Massiera G., Pitard E.
(Article) Publié:
Physical Review E: Statistical, Nonlinear, And Soft Matter Physics, vol. 97 p.012403 (2018)
Texte intégral en Openaccess :
Ref HAL: hal-01735760_v1
DOI: 10.1103/PhysRevE.97.012403
WoS: WOS:000423129000005
Exporter : BibTex | endNote
2 Citations
Résumé: Cilia are elastic hairlike protuberances of the cell membrane found in various unicellular organisms and in several tissues of most living organisms. In some tissues such as the airway tissues of the lung, the coordinated beating of cilia induce a fluid flow of crucial importance as it allows the continuous cleaning of our bronchia, known as mucociliary clearance. While most of the models addressing the question of collective dynamics and metachronal wave consider homogeneous carpets of cilia, experimental observations rather show that cilia clusters are heterogeneously distributed over the tissue surface. The purpose of this paper is to investigate the role of spatial heterogeneity on the coherent beating of cilia using a very simple one dimensional model for cilia known as the rower model. We systematically study systems consisting of a few rowers to hundreds of rowers and we investigate the conditions for the emergence of collective beating. When considering a small number of rowers, a phase drift occurs, hence a bifurcation in beating frequency is observed as the distance between rowers clusters is changed. In the case of many rowers, a distribution of frequencies is observed. We found in particular the pattern of the patchy structure that shows the best robustness in collective beating behavior, as the density of cilia is varied over a wide range.
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Mathematics of pattern growth in condensed matter Interfacial Wave Theory of Pattern Formation in Solidification: Dendrites, Fingers, Cells and Free Boundaries , Jian-Jun Xu, Springer, 2017 (2nd ed.). $159.00
Auteur(s): Truzzolillo D.
(Article) Publié:
Physics Today, vol. 71 p.56 - 57 (2018)
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Hydrodynamic instabilities in miscible fluids
Auteur(s): Truzzolillo D., Cipelletti L.
(Article) Publié:
Journal Of Physics: Condensed Matter, vol. 30 p.033001 (2018)
Texte intégral en Openaccess :
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