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Sanchez C.,CNRS Laboratory of Condensed Matter Chemistry, Paris | Belleville P.,CEA Le Ripault | Popall M.,Fraunhofer Institute for Silicate Research | Nicole L.,CNRS Laboratory of Condensed Matter Chemistry, Paris
Chemical Society Reviews | Year: 2011

Today cross-cutting approaches, where molecular engineering and clever processing are synergistically coupled, allow the chemist to tailor complex hybrid systems of various shapes with perfect mastery at different size scales, composition, functionality, and morphology. Hybrid materials with organic-inorganic or bio-inorganic character represent not only a new field of basic research but also, via their remarkable new properties and multifunctional nature, hybrids offer prospects for many new applications in extremely diverse fields. The description and discussion of the major applications of hybrid inorganic-organic (or biologic) materials are the major topic of this critical review. Indeed, today the very large set of accessible hybrid materials span a wide spectrum of properties which yield the emergence of innovative industrial applications in various domains such as optics, micro-electronics, transportation, health, energy, housing, and the environment among others (526 references). © 2011 The Royal Society of Chemistry.


An especially simple approach to the evaluation of flash point (FP) from additive fragment contributions is outlined. Being based on a square root expression derived from the examination of n-alkanes data, it avoids the need for nonlinear fitting procedures and for trial-and-error optimization of the analytical relationship between FP and molecular descriptors. Furthermore, in spite of a specially small number of additive contributions, the method can be applied to most organic molecules. For organosilicon compounds, it exhibits some advantages compared to previously available procedures, while providing very similar performances, with an average absolute deviation from experiment close to 12 K, a determination coefficient R 2 = 0.89 and only one error >40 K. © 2012 American Chemical Society.


Mathieu D.,CEA Le Ripault
Industrial and Engineering Chemistry Research | Year: 2012

Taking advantage of an extended data set of sublimation enthalpies recently used to develop an artificial neural network for the prediction of this property, an alternative model based on 35 atom and ring contributions is presently reported. The values predicted using both approaches are remarkably similar, although the present one is much simpler and less empirical. © 2012 American Chemical Society.


Mathieu D.,CEA Le Ripault
Journal of Energetic Materials | Year: 2015

A new analytic model is introduced to predict Gurney parameters of explosives from their empirical formula, density, and formation enthalpy. It involves the H2O-CO2 arbitrary, the assumption of a constant polytropic coefficient, and two empirical parameters. It is more physically grounded than previous models and proves twice more reliable, hence demonstrating that combining an analytic description of purely academic interest for hot gases with a small number of empirical parameters making up for its deficiencies proves superior to straightforward Quantitative Structure-Property Relationships (QSPR) approaches. © 2015, Taylor & Francis Group, LLC.


Mathieu D.,CEA Le Ripault
Journal of Hazardous Materials | Year: 2010

The problem of predicting flash points (T*) of alkanes from their molecular formula is revisited. Starting from an examination of the dependence of T* on the length of the carbon chain for n-alkanes, a new model is proposed. Despite its extreme simplicity, it performs better than published alternatives based on advanced regression techniques. This illustrates the interest of an inductive approach to quantitative structure-property relationships, whereby a model is first developed for restricted series of simple compounds before being generalized. © 2010 Elsevier B.V.


Mathieu D.,CEA Le Ripault
Industrial and Engineering Chemistry Research | Year: 2013

By analogy with recent models for flash point, the lower and upper flammability limit temperatures of organic compounds are represented as power law expressions in terms of fragment contributions. The predictive value of the resulting models compares well with recently published methods. A major advantage of the present approach is the fact it provides better insight into the relationships between flammability limit temperatures and molecular structure. © 2013 American Chemical Society.


Belleville P.,CEA Le Ripault
Comptes Rendus Chimie | Year: 2010

CEA's sol-gel laboratory is specialized in the development of innovative sol-gel optical coatings and has extended its application field to membrane materials and coatings for energy conversion, to electric coatings for microelectronics devices and to thin films for gas sensing. This article describes, by way of examples, the laboratory's research on sol-gel functional coatings, including nanomaterial synthesis, organic-inorganic hybrid-based solution preparation as well as deposition process development and prototyping. © 2010 Académie des sciences.


Mathieu D.,CEA Le Ripault
Journal of Hazardous Materials | Year: 2010

To satisfy the need of energetic materials chemists for reliable and efficient predictive tools in order to select the most promising candidates for synthesis, a custom software package is developed. Making extensive use of publicly available software, it integrates a wide range of models and can be used for a variety of tasks, from the calculation of molecular properties to the prediction of the performance of heterogeneous materials, such as propellant compositions based on ammonium perchlorate/aluminium mixtures. The package is very easy to use through a graphical desktop environment. According to the material provided as input, suitable models and parameters are automatically selected. Therefore, chemists can apply advanced predictive models without having to learn how to use complex computer codes. To make the package more versatile, a command-line interface is also provided. It facilitates the assessment of various procedures by model developers. © 2009 Elsevier B.V. All rights reserved.


Laberty-Robert C.,11 Place Marcelin Berthelot | Valle K.,CEA Le Ripault | Pereira F.,CEA Le Ripault | Sanchez C.,11 Place Marcelin Berthelot
Chemical Society Reviews | Year: 2011

This critical review presents a discussion on the major advances in the field of organic-inorganic hybrid membranes for fuel cells application. The hybrid organic-inorganic approach, when the organic part is not conductive, reproduces to some extent the behavior of Nafion where discrete hydrophilic and hydrophilic domains are homogeneously distributed. A large variety of proton conducting or non conducting polymers can be combined with various functionalized, inorganic mesostructured particles or an inorganic network in order to achieve high proton conductivity, and good mechanical and chemical properties. The tuning of the interface between these two components and the control over chemical and processing conditions are the key parameters in fabricating these hybrid organic-inorganic membranes with a high degree of reproducibility. This dynamic coupling between chemistry and processing requires the extensive use and development of complementary ex situ measurements with in situ characterization techniques, following in real time the molecular precursor solutions to the formation of the final hybrid organic-inorganic membranes. These membranes combine the intrinsic physical and chemical properties of both the inorganic and organic components. The development of the sol-gel chemistry allows a fine tuning of the inorganic network, which exhibits acid-based functionalized pores (-SO3H, -PO3H2, -COOH), tunable pore size and connectivity, high surface area and accessibility. As such, these hybrid membranes containing inorganic materials are a promising family for controlling conductivity, mechanical and chemical properties (349 references). © 2011 The Royal Society of Chemistry.


A new approach to the development and parametrization of reactive potentials for organic compounds is put forward. As a byproduct of preliminary efforts in this direction, the performance of a simple representation of the energy of equilibrium structures in term of pairwise atom-atom and bond-bond contributions is investigated. For now, each contribution is assumed constant, given the multiplicity of covalent bonds, rather than computed on-the-fly from geometries and bond orders. In spite of this rough approximation, the approach performs remarkably well by comparison with semiempirical quantum chemical methods. Nevertheless, further refinement proves necessary for some unstable species involved in chemical reactions. As it stands, the present model appears as a promising basis in view of less empirical and more versatile alternatives to group contribution methods for the fast prediction of heats of formation, although much work remains to be done to demonstrate its value as a starting point toward better reactive potentials. © 2012 American Chemical Society.

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