Conjugated Poly(ionic liquid)-Based Nanoporous Membrane for Rapid Moisture Response.

Stimuli-responsive nanoporous materials represent a newly emerging category of functional materials, for which instant and significant response behavior is strongly demanded but still challenging. Herein, a new kind of conjugated poly(ionic liquid)s (PILs) synthesized via a simple one-pot spontaneous nucleophilic substitution and polymerization between 4,4'-vinylenedipyridine and propargyl bromide is reported. A nanoporous membrane actuator is further developed via ionic complexation between the current PIL and trimesic acid. The actuator carries a gradient density in the hydrophobicity content along the membrane cross-section, which results in a fast response to moisture.