A New Type of Supramolecular Fluid Based on H 2 O–Alkylammonium/Phosphonium Solutions

Abstract Here we show that by adjusting the concentration of tetrabutyl ammonium and phosphonium salts in water (≈1.5–2.0 m), hydrophobic solvation triggers formation a unique, highly incompressible supramolecular liquid, with dynamic structure similar to clathrates, involving essentially all H 2 O molecules solvent. Despite increasing local order, thermal diffusivity, compressibility these liquids is strongly decreased respect bulk due slower relaxation dynamics. The results presented this paper open an avenue design new family fluids, stable under atmospheric conditions, which can find important technological applications energy storage conversion.