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DOI: 10.1088/0953-8984/28/7/075201
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10 Citations
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We introduce a temporal scheme for data sampling, based on a variable delay between two successive data acquisitions. The scheme is designed so as to reduce the average data flow rate, while still retaining the information on the data evolution on fast time scales. The practical implementation of the scheme is discussed and demonstrated in light scattering and microscopy experiments that probe the dynamics of colloidal suspensions using CMOS or CCD cameras as detectors.

Commentaires: Published in J. Phys.: Cond. Matter. 11 pages, 5 figures + Supporting Data (Python software to implement the method described in the manuscript)

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DOI: 10.1039/C5CP02742J
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In this work, we develop the concept of evaporation-induced self-structuring as a novel approach forproducing organised films by exploiting cooperative physical and chemical interactions under far-fromequilibriumconditions (spin-coating), using sol–gel precursors with multiple functional groups. Thin filmsof self-structured silsesquioxane nanohybrids have been deposited by spin coating through the sol–gelhydrolysis and condensation of a bridged organosilane bearing self-assembling urea groups. The resultingnanostructure, investigated by FTIR, AFM and SEM, is shown to be highly dependent on the catalyst used(nucleophilic or acidic), and can be further modulated by varying the spinning rate. FTIR studies revealed thepresence of highly organised structures under acidic catalysis due to strong hydrogen bonding between ureagroups and hydrophobic interactions between long alkylene chains. The preferential orientation of the ureacross-links parallel to the substrate is shown using polarized FTIR experiments.

PMID 26573173
DOI: 10.1039/c5sm01952d
WoS: 000369747900007
18 Citations
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The accumulation of colloidal particles to build dense structures from dilute suspensions may follow distinct routes. The mechanical, structural and geometrical properties of these structures depend on local hydrodynamics and colloidal interactions. Using model suspensions flowing into microfabricated porous obstacles, we investigate this interplay by tuning both the flow pattern and the ionic strength. We observe the formation of a large diversity of shapes, and demonstrate that growing structures in turn influence the local velocity pattern, favouring particle deposition either locally or over a wide front. We also show that these structures are labile, stabilised by the flow pushing on them, in low ionic strength conditions, or cohesive, in a gel-like state, at higher ionic strength. The interplay between aggregate cohesion and erosion thus selects preferential growth modes and therefore dictates the final shape of the structure.[on SciFinder (R)]

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DOI: 10.1021/acs.langmuir.5b03221
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Using aminoglycoside antibiotics as drug models, it was shown that electrostatic complexes between hydrophilic drugs and oppositely charged double-hydrophilic block copolymers can form ordered mesophases. This phase behavior was evidenced by using poly(acrylic acid)-block-poly(ethylene oxide) block copolymers in the presence of silica precursors, and this allowed preparing drug-loaded mesoporous silica directly from the drug-polymer complexes. The novel synthetic strategy of the hybrid materials is highly efficient, avoiding waste and multistep processes; it also ensures optimal drug loading and provides pH-dependence of the drug release from the materials.

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PMID 2564328
DOI: 10.1039/C4SM02891K
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DOI: 10.1016/j.cocis.2015.10.002
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The structure and dynamics of filler nanoparticles and macromolecules in polymer nanocomposites determine many aspects of macroscopic behavior, which is why these properties have attracted considerable interest in the scientific literature. In this article, recent progress using scattering techniques for the elucidation of structure and dynamics, of both filler nanoparticles and polymer chains, is reviewed. Small-angle X-ray and neutron scattering, more and more combined with direct imaging methods and simulations, are appropriate methods to investigate nanocomposite structure. While they can usually be applied to standard samples for filler structure, chain structure can only be accessed with neutrons and isotopic substitution, under the zero-average contrast condition to match the filler contribution. Quasi-elastic neutron scattering and X-ray photon correlation spectroscopy cover different time scales with spatial resolution in the nanoscale. The former allows studies of polymer motions from atomic or segmental relaxation to reptation of the entire chain in presence of filler, while the latter is increasingly used for investigations of nanoparticle dynamics.

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DOI: 10.1038/srep18002
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The development of visible-light responsive photocatalysts would permit more efficient use ofsolar energy, and thus would bring sustainable solutions to many environmental issues. Conductivepolymers appear as a new class of very active photocatalysts under visible light. Among them poly(3,4-ethylenedioxythiophene) (PEDOT) is one of the most promising conjugated polymer with a widerange of applications. PEDOT nanostructures synthesized in soft templates via chemical oxidativepolymerization demonstrate unprecedented photocatalytic activities for water treatment withoutthe assistance of sacrificial reagents or noble metal co-catalysts and turn out to be better than TiO2as benchmark catalyst. The PEDOT nanostructures exhibit a narrow band gap (E = 1.69 eV) and arecharacterized by excellent ability to absorb light in visible and near infrared region. The novel PEDOTbasedphotocatalysts are very stable with cycling and can be reused without appreciable loss of activity.Interestingly, hollow micrometric vesicular structures of PEDOT are not effective photocatalysts ascompared to nanometric spindles suggesting size and shape dependent photocatalytic properties.The visible-light active photocatalytic properties of the polymer nanostructures present promisingapplications in solar light harvesting and broader fields.