Abstract.
The temperature-induced microphase separation of the binary liquid system iso-butyric acid+heavy water (iBA + D2O) in a mesoporous silica glass (CPG-10-75) of nominal pore width 7.5 nm was investigated by neutron spin-echo spectroscopy (NSE) and neutron small-angle scattering (SANS). Two mixtures of different composition were studied at different scattering angles at temperatures above and below the bulk phase transition temperature. The phase separation in the pore space is found to occur at a lower temperature than the bulk transition and extends over a significant temperature range. The effective diffusion coefficient derived from NSE at low scattering angles is found to decrease by one order of magnitude from 70 ∘C to 20 ∘C. This observation is attributed to the growing size of concentration fluctuations having a cut-off at ca. 8 nm, which corresponds to the mean pore size. The dynamics of the concentration fluctuations appears to be strongly influenced by the confinement in the pores, as it differs strongly from the bulk behaviour. These results are consistent with the preliminary results of the SANS study.
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References
1. L.D. Gelb, K.E. Gubbins, R. Radhakrishnan, M. Sliwinska-Bartkowiak, Rep. Prog. Phys. 62, 3573 (1999)
2. A. Schreiber, H. Bock, M. Schoen, G.H. Findenegg, Molevular Phys. 100(53), 2997 (2002)
3. F. Porcheron, M. Schoen, Phys. Rev. E 66, 041205 (2002)
4. P.G. de Gennes, J. Phys. Chem. 88, 6469 (1984)
5. M.Y. Lin, S.K. Sinha, J.M. Drake, X.-I. Wu, P. Thiyagarajan, H.B. Stanley, Phys. Rev. Lett. 72(14), 2207 (1994)
6. S.B. Dierker, P. Wiltzius, Phys. Rev. Lett. 66, 1185 (1991)
7. F. Formisano, J. Teixeira, Eur. Phys. J. E 1, 1 (2000)
8. F. Formisano, J. Teixeira, J. Phys. Cond. Matt. 12, A351 (2000)
9. H.-H. Limbach, G. Buntkovsky, personel communication, slow relaxation is not accesible by NMR
10. Neutron Spin Echo, Vol. 124 of Lecture Notes in Physics, edited by F. Mezei (Springer Verlag, Berlin, 1980)
11. J.B. Hayter, in Scattering Techniques Applied To Supramolecular And Nonequilibrium Systems, edited by S.-H. Chen, B. Chu, R. Nossal (Plenum Press, New York, 1981), pp. 3–33
12. F. Mezei, C. Pappas, T. Gutberlet, Neutron Spin Echo Spectroscopy, Vol. 601 of Lecture Notes in Physics (Springer, Heidelberg, 2003)
13. P.G. de Gennes, Physica 25, 825 (1959)
14. A. Höhr, H.-B. Neumann, P.W. Schmidt, P. Pfeifer, D. Avnir, Phys. Rev. B 38, 1462 (1988)
15. FLUKA, CPG, Tech. Rep., Fluka Chemie AG
16. P. Gansen, D. Wörmann, J. Phys. Chem. 88, 2655 (1984)
17. G. Rother, Adsorption und Phasentrennung binärer flüssiger Mischungen in Porensystemen, Ph.D. thesis, TU Berlin (2002)
18. H. Furukawa, Physica 123A, 497 (1984)
19. P. Debye, H.R. Anderson Jr., H. Brumberger, J. Appl. Phys. 28, 679 (1957)
20. L. Auvray, P. Auroy, Scattering by Interfaces: Variations on Porod’s Law (Elsevier Science Publishers B.V., 1991), pp. 199–221
21. R. Papoular, La spectromètre par Echos de Spin de Neutron. Application à l’étude de la dynamique des polymers en solution, Ph.D. thesis, Université de Paris-Sud (1992)
22. S. Schemmel, G. Rother, T. Hellweg, H. Eckerlebe, G.H. Findenegg (2003), in preparation
23. B.J. Frisken, F. Ferri, D.S. Cannell, Phys. Rev. E 51, 5922 (1995)
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Hellweg, T., Schemmel, S., Rother, G. et al. De-mixing dynamics of a binary liquid system in a controlled-pore glass. Eur. Phys. J. E 12 (Suppl 1), 1–4 (2003). https://doi.org/10.1140/epjed/e2003-01-001-9
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DOI: https://doi.org/10.1140/epjed/e2003-01-001-9