Thermo-regulating mesoporous semi-rigid metal-organic-polymer frameworks for controllable adsorption and confinement

In nature, most living organisms are mesoscopic complex assemblages of soft and hard anisotropic blocks, featuring both outstanding mechanical performances and functional adaptability. A similar design also endows mesoporous metal-organic frameworks with limited flexibility but lacks specific stimulus-responsiveness and selectivity. So we introduced for the first time poly(acrylamide-co-acrylonitrile) (P(AAm-co-AN)) with upper critical solution temperature UCST into a conventional metal-organic framework (MOF) by a one-pot method, to construct a "living" metal-organic-polymer framework (MOPF) based on multiple coordination and dipolar interaction. The 3D "brick-and-mortar" MOPFs comprising rigid regular nanorods and amorphous flexible polymeric linkers exhibit attractive thermal responsiveness. Under thermal induction, the reversible interchain transition P(AAm-co-AN) brought about obvious variation in inner pore size. The confinement effect caused by pore variation further affects CO2 adsorption and aggregation-induced emissions. This thermo-regulatable confinement effect of "semi-rigid" MOPFs provides a novel, facile, and promising strategy of physicochemical manipulation for controllable substance loading.