Porous Liquids: The Next Frontier

Porous liquids (PLs) are a new class of materials with compositions ranging from discrete molecular cages to porous cages and colloidal particles stabilized by bulk molecules and electrostatic charges. A basic unifying principle among all types of PLs is that of size exclusion adsorption, which is governed by the pore openings and prevents self-adsorption. The open pores, having tailorable sizes and selectivity, make these fluids attractive for many applications and redefine homogeneous and heterogeneous separations, catalysis, and even carbon capture and energy storage technologies. These PLs are also new platforms for the design of porous solid materials and composites. Challenges in extracting the full potential of PLs include their high density, viscosity, and melting temperatures. Rationalizing PLs as ideal solutions or colloidal fluids, however, may provide a suitable platform for manipulating these and other physicochemical properties of PLs and for future developments in this field.