Large supramolecular structures in water-alcohol mixtures evidenced by elastic light scattering

Summary We report the results of different light scattering experiments, both elastic and quasi-elastic, performed as a function of temperature at different concentrations on a water-butoxyethanol (C₄E₁) mixture. The comparison of the obtained data with the results of SANS gives evidence of the amphiphilic character of the alcohol molecules. In particular, we observe such a property gives rise to a well-defined micellarlike structure. At low temperatures (T≤5°C) we find that the mixture exhibits a surprising behaviour, namely very large structures (of the order of 2000 ?) built by an intermicellar aggregation process. In addition when the light scattering data show the presence of such large aggregates, neutron data reveal the persisting presence of micelles of about 20 ?. Such a structural picture agrees with the behaviour of the viscosity data. Due to the relevance of its scientific content, this paper has been given priority by the Journal Direction.