Abstract
Porous liquids are an emerging class of microporous materials where intrinsic, stable porosity is imbued in a liquid material. Many porous liquids are prepared by dispersing porous solids in bulky solvents; these can be contrasted by the method of dissolving microporous molecules. We highlight the latter "Type II" porous liquids-which are stable thermodynamic solutions with demonstrable colligative properties. This feature significantly impacts the ultimate utility of the liquid for various end-use applications. We also describe a facile method for determining if a Type II porous liquid candidate is "porous" based on assessing the partial molar volume of the porous host molecule dissolved in the solvent by measuring the densities of candidate solutions. Conventional CO(2) isotherms confirm the porosity of the porous liquids and corroborate the facile density method.