Octanol‐rich and water‐rich domains in dynamic equilibrium in the pre‐ouzo region of ternary systems containing a hydrotrope. (25th October 2013)

• Record Type: Journal Article
• Authors: Diat, Olivier; Klossek, Michael L.; Touraud, Didier; Deme, Bruno; Grillo, Isabelle; Kunz, Werner; Zemb, Thomas
• Is Part Of: Journal of applied crystallography. Volume 46:Part 6(2013:Dec.)
• Page Start: 1665
• Page End: 1669
• Publication Date: 2013-10-25
• Subjects: Crystallography -- Periodicals; 548.05
• DOI: 10.1107/S002188981302606X
• Languages: English
• ISSNs: 0021-8898

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Ternary mixtures of medium‐chain fatty alcohols, water and a hydrotrope (such as ethanol), near the immiscibility gap, make stable single phases at constant temperature. Interestingly, in this `pre‐ouzo region' these single phases consist of two distinct nanoscopic pseudo‐phases, one octanol‐rich and one water‐rich. This domain of composition, which is known to produce strong light scattering and to separate under ultracentrifugation into two phases, has been studied using contrast variation in small‐angle neutron scattering (SANS) combined with small‐ and wide‐angle X‐ray scattering (SWAXS). The existence of fatty alcohol‐rich domains of well defined size of the order of 2 nm radius is proven. The scattering can be approximated by an Ornstein–Zernike function, which is close to the general expression of Choi, Chen, Sottmann &amp; Strey [<italic>Physica B</italic>, (1998), <bold>241–243</bold>, 976–978] with vanishing quadratic Porod term. Exploitation of the relative intensities at the vanishing scattering angle in SANS demonstrates that the distribution coefficient of ethanol between the octanol‐rich and the water‐rich domains is close to one. WAXS of the two coexisting pseudo‐phases is compared with the corresponding binary water–ethanol and octanol–ethanol samples.</p> </abstract>