Effects of chaotropic and kosmotropic solutes on the structure of lipid cubic phase: Monoolein-water systems

Using X-ray diffraction technique, we investigated the modulation of the bi continuous cubic structure of monoacylglycerol (monoolein)-water systems by the presence of solutes. X-ray diffraction results demonstrated that chaot ropic solutes (NaSCN, NaI, and urea) expand the lattice constants of fully hydrated monoolein in Pn3m cubic phase and on the other hand, that kosmotro pic solutes (Na2SO4, NaCl, and sucrose) reduce the lattice constants. These results can be interpreted as suggesting that kosmotropes reduce the inter facial area and that chaotropes expand the interfacial area, by assuming in dependence of the molecular length of monoolein on the presence of solutes.