8 abr 2014

SEMINARIOS IQFR: "Dynamics and phase transitions of complex fluids adsorbed on porous glasses"


Programa del Ciclo de Seminarios del IQFR 2014


              Seminario del Dra. Cecilia Bores Quijano

"Dynamics and phase transitions of complex fluids adsorbed on porous glasses"

               Miércoles 9 de abril a las 12.00
                  Salón de Actos IQFR-CSIC


"Dynamics and phase transitions of complex fluids adsorbed on porous glasses"
C. Bores1, E.Lomba1, G. Kahl2

2 Insitut für Theoretische Physik and Center for Material Science, TU Wien

Complex fluids considered in this work are simple models of colloids or protein solutions which are known to present a rich phase behaviour. These systems are modelled by the short-atractive long-repulsive potential described in [1] which typically gives rise to rich microphase formation.
The structural and dynamical properties of fluids with competing interactions, and the influence of confinement and randomness on their behaviour, have already been studied [2] [4]. These studies have confined the fluids in hard walls, ordered and disordered hard spheres matrices, ... but controlled-pore glasses have never been considered yet.
Porous glasses present important advantages, for instance the pores size can be tuned with the manufacturing parameters. They are produced by demixing a mixture into two phases by means of the spinodal decomposition process, and removing one of the phases that is soluble in acid [5]. In this way, we mimic the manufacturing process of porous glasses using a simple 2D binary mixture of non additive hard spheres, that also exhibits this spinodal separation. Semi-grand canonical Monte Carlo simulations of this NAHS system provide the pore configurations, and Delaunay decomposition and other geometrical analysis [3] allows us to characterize the porous systems previously generated.
Fluids with competing interactions have been simulated by means of grand canonical Monte Carlo programs. Both situations, bulk and adsorbed fluids in porous glasses have been studied by analysing the clustering and correlation functions, in order to know the effect of the confinement on the pattern formation. The dynamics of these systems will also be analysed in the framework of Krakoviack's extension of the mode Coupling Theory to porous fluids[3] [6] and integral equation theory.
The aim of this research is the study of both dynamic, thermodynamic and structural properties of fluids with competing interactions confined in model controlled-pore glasses.

[1] A. Imperio and L. Reatto, Journal of Phys.: Condens. Matter 16, S3769-S3789 (2004)
[2] A. Imperio and L. Reatto,  The Journal of Chem. physics 124, 164712 (2006)
[3] J. Kurzidim and G. Kahl,  Mol. Physics 109, 1331-1342 (2011)
[4] D.F.Schwanzer, G. Kahl,  Cond. Matter Phys. 14, 3, 33801 (2011)
[5] L.D.Gelv, K. E. Gubbins, Langmuir 14, 2097-2111 (1998)
[6]  V. Krakoviack, Phys. Rev. Letters 94, 065703 (2005)

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