8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Tue 611:23-14:00P2.57Local internal pressures in aqueous and alcoholsolutionsNubia Mendoza, 1 Mercedes Cáceres, 1 Mercedes Taravillo, 1 and Valentin GarcíaB. 11 Universidad Complutense de Madrid, Ciudad Universitaria S/N, Depto. Quimica-FísicaFac. Ciencias Quimica 28040, Madrid, SpainOur goal is to confirm that the mixture effects can be correlated to external pressures applied toneat liquids, so a local internal pressure due to mixing can be defined unambiguously. In orderto establish such correlation we performed a series of Raman experiments. We first measured thehigh pressure Raman spectra of the pure liquids up to 1000 MPa in order to correlate the observedRaman shifts to external pressures. We later measured the Raman spectra of several mixtures atroom pressure. Specifically, we have measured the water plus methanol, water plus ethanol andmethanol plus ethanol solutions over the whole composition range. Since methanol is being one ofthe simplest anfifilic molecules this work can also serve as a reference for more complex systemslike micelles, bilayers, etc. in different solvents. The mixture ethanol-methanol completes ourstudy and has special impact for the high pressure community for its use as a hydrostatic media.This work was supported by MICINN and Comunidad de Madrid under research projects MALTA-Consolider CSD2007-00045, CTQ2009-14596-C02-01 and S2009/PPQ-1551.57