The production of nanoparticles (NPs) is increasing rapidly for applications in electronics, chemistry, and biology. This interest due to the very small size NPs which provides them with many interesting properties such as rapid diffusion, high specific surface areas, reactivity liquid or gas phase, a close biomacromolecules. In turn, these extreme abilities might be problem when considering potentially uncontrolled exposure environment. For instance, highly mobile transported environment...

Cerium dioxide nanoparticles have been proposed for an increasing number of applications in biomedicine, cosmetic, as polishing materials and also byproducts from automotive fuel additives. The aim this study was to examine the potential vitro cyto- genotoxicity nano-sized CeO2 (7 nm) on human dermal fibroblasts. By combining a physico-chemical (geno)toxicological approach, we defined causal mechanisms linking properties nano-CeO2 with their biological effects. Using X-ray absorption...

The heteroaggregation of engineered nanoparticles (ENPs) with natural colloids (NCs), which are ubiquitous in surface waters, is a crucial process affecting the environmental transport and fate ENPs. Attachment efficiencies for heteroaggregation, αhetero, required as input parameters models to predict ENP concentrations contribute risk assessment. Here, we present novel method determining αhetero values by using combination laser diffraction measurements aggregation modeling based on...

Physico-chemical interactions between nanoparticles and cell membranes play a crucial role in determining the cytotoxicity of nanoparticles, which may thereby vary depending on nature target microorganisms. We investigated responses two different models unicellular bacteria to cerium oxide (CeO2) nanoparticles. These organisms are: Synechocystis PCC6803 representative environmentally important cyanobacterial (producer biomass for aquatic food chains), Escherichia coli intestine-colonizing...

Abstract Liquid crystals have found wide applications in many fields ranging from detergents to information displays and they are also increasingly being used the ‘bottom-up’ self-assembly approach of material nano-structuration. Moreover, liquid-crystalline organizations frequently observed by biologists. Here we show that one four major lyotropic liquid-crystal phases, columnar one, is much more stable on dilution than reported so far literature. Indeed, aqueous suspensions imogolite...

The CeO2 NPs are increasingly used in industry but the environmental release of these and their subsequent behavior biological effects currently unclear. This study evaluates for first time on survival swimming performance two cladoceran species, Daphnia similis pulex after 1, 10 100 mg.L−1 exposures 48 h. Acute toxicity bioassays were performed to determine EC50 exposed daphnids. Video-recorded both daphnids was measure speeds various aggregated NPs. acute ecotoxicity showed that D. is 350...

Large amounts of regular tetrapods and hexapods made a central silica core four or six polystyrene satellite nodules were prepared with yields over 80% from 55 nm 85 seeds, respectively. The robustness the process is supported by extensive statistical analyses large-field transmission electron microscopy images.

It is known that silicon can be successfully replaced by germanium atoms in the synthesis of imogolite nanotubes, leading to shorter and larger AlGe nanotubes. Beside change morphology, two characteristics nanotube were recently discovered. nanotubes synthesized at much higher concentrations than AlSi imogolite. exists form both single-walled (SW) double-walled (DW) whereas DW imogolites have never been observed. In this article, we give details on physicochemical control over SW or...

Different shapes: Tetravalent, hexavalent, and dodecavalent silica particles were obtained by the growth of core binary tetrapods, hexapods, dodecapods, respectively. The surface multivalent can be regioselectively functionalized, thereby leading to with anisotropic geometry chemistry.

Composite organic/inorganic latexes encapsulating CeO2 nanoparticles were successfully synthesized by surfactant-free emulsion polymerization. Since carboxylic acid groups are known to interact strongly with the surface of CeO2, either a poly(acrylic acid) (PAA) homopolymer or random copolymer acrylic (AA) and n-butyl acrylate (BA) was first in solution using trithiocarbonate compounds as RAFT agents. The interaction between resulting macroRAFT agents investigated study adsorption isotherms....

New developments in nanosciences and nanotechnologies are strongly dependent on our ability to synthesize well-controlled nanobuilding units, with specific properties. We report this paper the first synthesis of hybrid single-walled imogolite nanotubes (OH)3Al2O3SixGe1–xCH3 diameter-controlled hydrophobic nanopores varying from 1.8 2.4 nm. Methylation nanotube dimensions studied by combining infrared spectroscopy, cryo-TEM observations, X-ray scattering measurements. show that, solution,...

Micron-long germanium-based double-walled imogolite nanotubes were synthesized at high concentrations, as evidenced by cryo-TEM, AFM, SAXS and IR characterization methods. In addition, the spontaneous formation of a liquid-crystalline phase was observed. The novel synthesis route made it possible for first time to obtain both long concentrated imogolite-like in single step.

Protein adsorption on a surface is generally evaluated in terms of the evolution proteins' structures and functions. However, when that nanoparticle, protein corona formed around it possesses particular supramolecular structure gives "biological identity" to new object. Little known about actual shape corona. Here, by model proteins (myoglobin hemoglobin) silica nanoparticles was studied. Small-angle neutron scattering oxygenation studies were combined assess both structural functional...

Nanoparticles confined in droplets of less than a picoliter are forced to organize submicronic dry grains through solvent evaporation. The evolution structures the and constituent nanoparticles during slow drying process investigated situ with small-angle X-ray scattering (SAXS) for first time. results have been explained on basis equilibrium thermodynamics tube. We demonstrate that this technique is really efficient describing internal arrangement inside droplets. Distinction between an...

The growth mechanisms of imogolite-like aluminogermanate nanotubes have been examined at various stages their formation. accurate determination the nucleation stage was using a combination local- (XAS Ge−K edge and 27Al NMR) semilocal scale technique (in situ SAXS). For first time, model is proposed for precursors nanotubular structure consist in rooftile-shaped particles, up to 5 nm size, with ca. 26% Ge vacancies varying curvatures. These assemble form short nanotubes/nanorings observed...

It has been recently discovered that the synthesis of Al−Ge imogolite-like nanotubes is possible at high concentration. Despite this initial success, structure these remains not completely understood. Using resolution cryo-TEM and Small Angle X-ray Scattering, we unravel their mesoscale in two contrasted situations. On one hand, imogolite synthesized 0.25 M are double-walled 4.0 ± 0.1 nm with an inner tube 2.4 nm. Moreover, SAXS data also suggest concentric tubes have equal length identical...

The inorganic manufactured nanoparticles as TiO2, Ag°, the iron oxides and CeO2 are more present in various products aqueous media (TiO2). Their dispersion ecosystems during their life cycle will be associated with interactions biota (plants, bacteria, fishes). work shows strong relations between particular physical chemical properties of very small (size < 30 nm) biological activity perturbations. It is shown that Ag° act at low concentrations. TiO2 via ROS production due to...

The growth of gold nanorods has been followed by small angle X-ray scattering and absorption. synthesis is performed at high concentration 3.5 mM in using situ generation seeds. It shown that the occurs constant number density nanoparticles after initial nucleation seeds final step reduction Au(I) to Au(0) only surface growing nanorods. Anisotropy acquired during with a ratio longitudinal basal rates measured 12. aspect limited available amount material experiment overgrowth was allowed...

Atomic Force Microscopy (AFM) and in situSmall Angle X-ray Scattering (SAXS) were used to investigate the evolution of aluminogermanate imogolite-like nanotubes concentration morphology during their synthesis. In particular, situSAXS allowed quantifying transformation protoimogolite into nanotubes. The size distribution final was also assessed after growth by AFM. A particular attention focused on determination single double walled nanotube length distributions. We observed that two types do...