Hostname: page-component-848d4c4894-ttngx Total loading time: 0 Render date: 2024-05-04T09:19:32.027Z Has data issue: false hasContentIssue false
  • English
  • Français

Dielectric and Mechanical Relaxation of Glass-Forming Liquids in Nanopores

Published online by Cambridge University Press:  10 February 2011

H. Wendt  and
R. Richert
H. Wendt
Affiliation:
Max-Planck-Institut fuir Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany
R. Richert
Affiliation:
Max-Planck-Institut fuir Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany
Get access

Abstract

We have measured the time resolved phosphorescence of different probe molecules in glassforming solvents under the condition of geometrical confinement in porous glasses. This solvation dynamics technique probes the local dielectric relaxation in the case of a dipolar chromophore in polar liquids. In the absence of dipolar interactions, the observed Stokes shifts reflect the local density or mechanical responses. Therefore, both orientational and translational modes of molecular motions can be measured for liquids imbibed in porous silica glasses. The effect of confinement on the relaxations of supercooled liquids is strongly dependent on the surface chemistry and can be rationalized on the basis of the cooperativity concept. As in the bulk case, we find that the relaxations in nano-confined liquids display heterogeneous dynamics. The density relaxation turns out to be more sensitive to the thermal history relative to the orientational features of molecular motion. By selectively positioning the chromophores at the liquid/solid interface, we observe also that the structural relaxation of the liquid in the immediate vicinity of the glass surface is slowed down but not entirely blocked.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 543: Symposium W – Dynamics in Small Confining Systems IV , 1998 , 15
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Dynamics in Small Confining Systems III, edited by Drake, J.M., Klafter, J. and Kopelman, R. (Mater. Res. Soc. Proc. 464, Pittsburgh, PA, 1997).Google Scholar
2. Molecular Dynamics in Restricted Geometries, edited by Klafter, J. and Drake, J.M. (John Wiley, New York, 1989).Google Scholar
3. Jackson, C.L. and McKenna, G.B., J. Non-Cryst. Solids 131–133, 221 (1991).Google Scholar
4. Petychakis, L., Floudas, G. and Fleischer, G., Europhys. Lett. 40, 685 (1997).Google Scholar
5. Richert, R., Phys. Rev. B 54, 15762 (1996).Google Scholar
6. Adam, G. and Gibbs, J.H., J. Chem. Phys. 43, 139 (1965).Google Scholar
7. Zhou, H.-X., Bagchi, B., Papazyan, A. and Maroncelli, M., J. Chem. Phys. 97, 9311 (1992).Google Scholar
8. Richert, R., Stickel, F., Fee, R.S. and Maroncelli, M., Chem. Phys. Lett. 229, 302 (1994).Google Scholar
9. R. Richert in Disorder Effects on Relaxational Processes, edited by Richert, R. and Blumen, A. (Springer-Verlag, Berlin, 1994).Google Scholar
10. Schwalb, G., Deeg, F.W. and Bräuchle, C., J. Non-Cryst. Solids 172–174, 348 (1994).Google Scholar
11. Farrer, R.A., Loughnane, B.J. and Fourkas, J. T., J. Phys. Chem. 101, 4005 (1997).Google Scholar
12. C. Streck, Melnichenko, Y.B. and Richert, R., Phys. Rev. B 53, 5341 (1996).Google Scholar
13. Yan, X., Streck, C. and Richert, R., Mat. Res. Soc. Symp. Proc. 464, 33 (1997).Google Scholar
14. Richert, R., J. Phys.: Condens. Matter 8, 6185 (1996).Google Scholar
15. Fourkas, J.T., Benigno, A. and Berg, M., J. Non-Cryst. Solids 172–174, 234 (1994).Google Scholar
16. Berg, M., J. Phys. Chem. A 102, 17 (1998).Google Scholar
17. Wendt, H. and Richert, R., J. Phys. Chem. A 102, 5775 (1998).Google Scholar
18. Richert, R. and Wagener, A., J. Phys. Chem. 95, 10115 (1991).Google Scholar
19. Wendt, H. and Richert, R., J. Phys.: Condens. Matter (in press).Google Scholar
20. Williams, G. and Watts, D.C., Trans. Faraday Soc. 66, 80 (1970).Google Scholar
21. Donati, C. and Jackie, J., J. Phys.: Condens. Matter 8, 2733 (1996).Google Scholar
22. Reichardt, C., Solvents and Solvent Effects in Organic Chemistry (VCH, Weinheim, 1988).Google Scholar
23. Richert, R. and Wagener, A., J. Phys. Chem. 97, 3146 (1993).Google Scholar
24. Ediger, M.D., Angell, C.A. and Nagel, S.R., J. Phys. Chem. 100, 13200 (1996).Google Scholar
25. Schmidt-Rohr, K. and Spiess, H.W., Phys. Rev. Lett. 66, 3020 (1991).Google Scholar
26. Böhmer, R., Chamberlin, R.V., Diezemann, G., Geil, B., Heuer, A., Hinze, G., Kuebler, S.C., Richert, R., Schiener, B., Sillescu, H., Spiess, H.W., Tracht, U., Wilhelm, M., J. Non-Cryst. Solids 235–237, 1 (1998).Google Scholar
27. Richert, R., J. Phys. Chem. B 101, 6323 (1997).Google Scholar
28. Richert, R., J. Non-Cryst. Solids 235–237, 41 (1998).Google Scholar
29. Richert, R. and Richert, M., Phys. Rev. E 58, 779 (1998).Google Scholar
30. Stephens, M.D., Saven, J.G. and Skinner, J.L., J. Chem. Phys. 106, 2129 (1997)Google Scholar