Oscillations, Waves, and Interactions - GWDG

Liquids: Formation of complexes and complex dynamics 397
Figure 29. Maximum values in the excess attenuation spectra (•) and the critical contribution
to the spectra (◦) displayed as a function of critical micelle concentration for a
variety of CiEj − H2O mixtures at 25 ◦ C (C7E3 at 22.5 ◦ C; C10E4 at 18 ◦ C [16]).
5 Conclusions
Liquids are characterized by a rich variety of rapidly fluctuating structures, including
short living dimers as well as complexes formed from micelles, being aggregates themselves.
The diversity in the molecular dynamics resulting thereby can be favourably
studied by acoustical spectrometry. Compressional waves couple to nearly all relevant
molecular mechanisms, covering a broad range of frequencies and thus relaxation
times. Though naturally rather nonspecific, variations of the temperature of the liquid
and of the concentration and chemical composition of constituents enable definite
results on thermodynamic and tranport parameters, which are difficult to obtain otherwise.
Specific insights into even complex dynamics is enabled thereby, especially if
additional experimental methods are used for complementary information.
References
[1] I. Ohmine and H. Tanaka, ‘Fluctuation, Relaxations, and Hydration in Liquid Water.
Hydrogen-Bond Rearrangement Dynamics’, Chem. Rev. 93, 2545 (1993).
[2] U. Kaatze, R. Behrends, and R. Pottel, ‘Hydrogen Network Fluctuations and Dielectric
Spectrometry of Liquids’, J. Non-Crystalline Solids 305, 19 (2002).
[3] U. Kaatze, in Electromagnetic Aquametry, Electromagnetic Wave Interaction with
Water and Moist Substances, edited by K. Kupfer (Springer, Berlin, 2005).
[4] A. M. Belloc, Membranes, Microemulsions and Monolayers (Springer, Berlin, 1994).
[5] D. F. Evans and H. Wennerström, The Colloidal Domain. Where Physics, Chemistry,
and Biology Meet (Wiley-VCH, New York, 1999).