Emulsion templating: DIY versatility for the creative design of macroporous polymers

Porous polymers are of interest for a wide variety of applications including absorption, adsorption, tissue engineering, membranes, controlled release, reaction supports, and shape memory foams. Emulsion templating can be used to generate high-porosity, macroporous polymer monoliths with highly interconnected, micrometer-scale porous structures through polymerization in the external, continuous phase followed by removal of the internal, dispersed phase. Emulsion templating possesses, on one hand, the benefit of being seemly simple. This simplicity, however, belies its inherent versatility and considerable parameter space that enables creative design of innovative new materials in terms of their macromolecular structures, their porous structures, and their properties. As described here, approaching emulsion templating with a specific structure or application in mind can enable a do-it-yourself outlook to imaginatively selecting the most appropriate emulsion type, stabilization strategy, polymerization mechanism, crosslinking strategy, and post-synthesis modification. The research and development of emulsion-templated polymers has been blossoming, as reflected not only in the number of articles published, but also in the number of novel porous polymer materials synthesized and in the number of heretofore unexplored applications investigated. It is the hidden complexity of emulsion templating that enables a continuous stream of pioneering works stemming from breakthrough insights in connected and contiguous scientific fields. This appraisal, highlighting emulsion templating strategies, will serve as a guide for those involved in developing innovative polymers with unique macromolecular and porous structures that engender exceptional properties. Contemplating the future directions of emulsion templating, given the robust nature of its established foundation, suggests that innovative research and development will continue to flourish.