49-3 FIELD Section Title:Industrial Inorganic Chemicals 60, 61, 77 Laboratoire de Physicochimie des Electrolytes, Colloides et Sciences Analytiques, (PECSA-UMR 7195 UPMC-CNRS-ESPCI) UPMC - 4, Paris, Fr. FIELD URL: written in EnglishWe describe the prepn. of magnetic silica nanocomposite millimetric beads using alginate as a green biopolymer template. The simple and soft method which is used here is particularly suitable since the alginate template allows a multiscale control of the structure of the material, both its morphol. characteristics at the millimetric scale and its porosity at the nanometric level. These nanocomposites are characterized by a high monodispersity, a perfect spherical shape, a very large and multiscale porosity with pore diams. ranging from 2 nm to more than 50 nm, a homogeneous dispersion of the magnetic nanoparticles in the silica matrix and a high magnetic susceptibility which increases linearly with the vol. fraction of the nanoparticles. These highly porous materials which can be used as magnetic adsorbents in water treatment, showed a good sorption capacity for methylene blue, chosen as a model dye. [on SciFinder(R)

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This paper presents a new mathematical representation of multiphase thermodynamic equilibrium using so-called repartition coefficients. Combined with a global mass formulation of multiphase Darcy flow in porous media, it allows the derivation of a computationally efficient family of time schemes. The model accounts for the mass conservation of an arbitrary number of components flowing through an arbitrary number of phases, coupled with thermodynamic equilibrium and pore volume conservation. By separating the thermodynamic equilibrium part from the flow part through the repartition coefficients, the formulation removes the need for any specific handling of phase appearance and disappearance within the flow solver. Any "black box" thermodynamic equilibrium solver can then be used to compute the repartition coefficients, from EOS based solvers to tabulated representation of the thermodynamic equilibrium, each specific choice of thermodynamic solver leading to a new scheme. Three numerical experiments, from a simple beam to a real case, illustrate the good behavior of the approach.