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7 results on '"Spalla, Olivier"'

1. Role of the environment in the stability of anisotropic gold particles

Author

Fleury, Blaise, Cortes-Huerto, Robinson, Taché, Olivier, Testard, Fabienne, Menguy, Nicolas, Spalla, Olivier, Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Chemistry, Isotropy, Nucleation, General Physics and Astronomy, Nanoparticle, Nanotechnology, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Kinetic energy, 01 natural sciences, Stability (probability), 0104 chemical sciences, Equilibrium thermodynamics, Chemical physics, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Physical and Theoretical Chemistry, Facet, 0210 nano-technology, Anisotropy
Abstract

International audience; Despite the long-lasting interest in the synthesis control of nanoparticles (NPs) in both fundamental and applied nanosciences, the driving mechanisms responsible for their size and shape selectivity in an environment (solution) are not completely understood, and a clear assessment of the respective roles of equilibrium thermodynamics and growth kinetics is still missing. In this study, relying on an efficient atomistic computational approach, we decipher the dependence of energetics, shapes and morphologies of gold NPs on the strength and nature of the metal–environment interaction. We highlight the conditions under which the energy difference between isotropic and elongated gold NPs is reduced, thus prompting their thermodynamic coexistence. The study encompasses both monocrystalline and multi-twinned particles and extends over size ranges particularly representative of the nucleation and early growth stages. Computational results are further rationalized with arguments involving the dependence of facet and edge energies on the metal–environment interactions. We argue that by determining the abundance and diversity of particles nucleated in solution, thermodynamics may constitute an important bias influencing their final shape. The present results provide firm grounds for kinetic simulations of particle growth.

Published
2015
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2. Evidence of double-walled Al-Ge imogolite-like nanotubes. A cryo-TEM and SAXS investigation

Author

Maillet, Perrine, Levard, Clement, Larquet, Eric, Mariet, Clarisse, Spalla, Olivier, Menguy, Nicolas, Masion, Armand, Doelsch, Emmanuel, Rose, Jerome, and Thill, Antoine

Subjects
Aluminum -- Chemical properties, Germanium -- Chemical properties, Nanotubes -- Structure, Nanotubes -- Chemical properties, Transmission electron microscopes -- Usage, Chemistry
Abstract

High resolution cryo-TEM and Small Angle X-ray scattering are used for understanding the mesoscale structure of Al-Ge imogolite-like nanotubes in two contrasted situations. SAXS data has shown that the two concentric tubes have an equal length and identical wall structure and both SAXS and cryo-TEM data has confirmed the formation of single-walled nanotube at higher concentration.

Published
2010

3. Understanding of the size control of biocompatible gold nanoparticles in millifluidic channels

Author

Spalla Olivier, Malloggi Florent, Pierre-Eugène Coulon, Menguy Nicolas, Testard Fabienne, and Han Jun

Subjects
Aqueous solution, Materials science, Molecular Structure, Reducing agent, Scattering, Surface Properties, Dispersity, Nucleation, Nanoparticle, Metal Nanoparticles, Nanotechnology, Biocompatible Materials, Surfaces and Interfaces, Microfluidic Analytical Techniques, Condensed Matter Physics, chemistry.chemical_compound, Monomer, chemistry, Colloidal gold, Electrochemistry, General Materials Science, Gold, Particle Size, Spectroscopy
Abstract

The size control of gold nanoparticles synthesized in surfactant free water with a continuous flow mode was elucidated and used to produce higher concentration (3 mM) of stabilized gold nanoparticles. The originality of the synthesis was to finely modulate the initial pH of the reducing agent instead of the gold precursor to modify the kinetic of the reaction. The acceleration of the kinetic (~1 s) prevents the modification of the gold precursors ensuring the control of the final size (from 3 to 25 nm) of the nanoparticles with a low polydispersity for aqueous surfactant free solution. The accurate measure of the size distribution by small angle X-ray scattering was combined to the use of a model based on the coupling of nucleation and growth equations together with a progressive injection of monomers. The results on the final state show that the size of the nanoparticles is indeed controlled by the kinetic of reduction of gold atoms. A millifluidic setup equipped with a homemade mixer offers a robust way of rapid mixing to obtain a reproducible production of large amounts of nanoparticles.

Published
2012

4. Synthesis and liposome insertion of a new poly(carbonylalkylthio)porphyrazine to improve potentiality in multiple-approach cancer therapy

Author

Ristori, Sandra, Salvati, Anna, Martini, Giacomo, Spalla, Olivier, Pietrangeli, Daniela, Rosa, Angela, and Ricciardi, Giampaolo

Subjects
Carbonyl compounds -- Chemical properties, Carbonyl compounds -- Structure, Liposomes -- Research, Chemistry
Abstract

Synthesis of a new poly(carbonylalkylthio)porphyrazine is presented. Experimental and theoretical data showed that interactions between the new polycarbonyl porphyrazine and the polar heads of liposome is a useful strategy for the design of new tetrapyrrolic systems to be loaded in liposomes and delivered through the membrane of cancerous tissues.

Published
2007

5. Chemical waves and pattern formation in the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/water lamellar system

Author

Magnani, Agnese, Marchettini, Nadia, Ristori, Sandra, Rossi, Federico, Spalla, Olivier, Rossi, Claudio, Rustici, Mauro, and Tiezzi, Enzo

Subjects
Lipid membranes -- Research, Belousov-Zhabotinskii reaction -- Usage, Chemistry
Abstract

A Belousov Zhabotinsky(BZ) reaction, which is carried out in the anisotropic environment of the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine(DPPC)/water binary system that presents layered aqueous domains separated by lipid bilayers are studied. Experiments on BZ behavior were carried out at room temperature by mixing DPPC with all the reactants, except ferroin, in a beaker under stirring.

Published
2004

6. Cytotoxicity of CeO2 Nanoparticles for Escherichia coil. Physico-Chemical Insight of the Cytotoxicity Mechanism.

Author

Thill, Antoine, Zeyons, Ophélie, Spalla, Olivier, Chauvat, Franck, Rose, Jerôme, Auffan, Mélanie, and Flank, Anne Marie

Subjects
*CELL-mediated cytotoxicity, *NANOPARTICLES, *ESCHERICHIA coli, *ELECTRONICS, *CHEMISTRY, *BIOLOGY, *SURFACE area, *BIOMACROMOLECULES, *PARTICLES
Abstract

The production of nanoparticles (NPs) is increasing rapidly for applications in electronics, chemistry, and biology. This interest is due to the very small size of NPs which provides them with many interesting properties such as rapid diffusion, high specific surface areas, reactivity in liquid or gas phase, and a size close to biomacromolecules. In turn, these extreme abilities might be a problem when considering a potentially uncontrolled exposure to the environment. For instance, nanoparticles might be highly mobile and rapidly transported in the environment or inside the body through a water or air pathway. Accordingly, the very fast development of these new synthetic nanomaterials raises questions about their impact on the environment and human health. We have studied the impact of a model water dispersion of nanoparticles (7 nm CeO2 oxide) on a Gram-negative bacteria (Escherichia coli). The nanoparticles are positively charged at neutral pH and thus display a strong electrostatic attraction toward bacterial outer membranes. The counting of colony forming units (CFU) after direct contact with CeO2 NPs allows for the defining of the conditions for which the contact is lethal to Escherichia coli. Furthermore, a set of experiments including sorption isotherms, TEM microscopy, and X-ray absorption spectroscopy (XAS) at cerium L3 edge is linked to propose a scenario for the observed toxic contact. [ABSTRACT FROM AUTHOR]

Published
2006
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7. Surface Chemistry of Nanometric Ceria Particles in Aqueous Dispersions

Author

Bernard Cabane, Olivier Spalla, Minou Nabavi, Laboratoire Interdisciplinaire sur l'Organisation Nanométrique et Supramoléculaire (LIONS), Nanosciences et Innovation pour les Matériaux, la Biomédecine et l'Energie (ex SIS2M) (NIMBE UMR 3685), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire Colloïdes et Matériaux Divisés (LCMD), Centre National de la Recherche Scientifique (CNRS)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Spalla, Olivier, Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
chemistry.chemical_classification, [CHIM.MATE] Chemical Sciences/Material chemistry, Aqueous solution, Inorganic chemistry, Oxide, Aqueous dispersion, 02 engineering and technology, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Biomaterials, chemistry.chemical_compound, Colloid and Surface Chemistry, Adsorption, chemistry, Desorption, Titration, Particle size, 0210 nano-technology, Inorganic compound, ComputingMilieux_MISCELLANEOUS
Abstract

The oxide/water interface of nanometric ceria particles has been studied through titration of the surface sites. The adsorption and desorption of protons, hydroxyls, and anions have been measured through potentiometry and chemical analysis. It has been found that these processes cause reactions between surfaces. Conversely, the loss of reactive surfaces which results from chemical treatments changes the charge behavior of the dispersions and reduces it to that of the pure fired oxide.

Published
1993

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