Developing a synthetic methodology for the fabrication of hierarchically porous metal-organic monoliths that feature high surface area, low density and tunable porosity is imperative for mass transfer applications, including bulky molecule capture, heterogeneous catalysis and drug delivery. Here we report a versatile and facile synthetic route towards ultralight micro/mesoporous metal-organic aerogels based on the two-step gelation of metal-organic framework nanoparticles. Heating represents a key factor in the control of gelation versus crystallization of Al(III)-multicarboxylate systems. The porosity of the resulting metal-organic aerogels can be readily tuned, leading to the formation of well-ordered intraparticle micropores and aerogel-specific interparticle mesopores, thereby integrating the merits of both crystalline metal-organic frameworks and light aerogels. The hierarchical micro/mesoporosity of the Al-metal-organic aerogels is thoroughly evaluated by N2 sorption. The good accessibility of the micro/mesopores is verified by vapour/dye uptake, and their potential for utilization as effective fibre-coating absorbents is tested in solid-phase microextraction analyses.
Embedding an enzyme within aMOF as exoskeleton (enzyme@MOF) offers new opportunities to improve the inherent fragile nature of the enzyme,but also to impart novel biofunctionality to the MOF.D espite the remarkable stability achieved for MOF-embedded enzymes,e mbedding patterns and conversion of the enzymatic biofunctionality after entrapment by aM OF have only received limited attention. Herein, we reveal howe mbedding patterns affect the bioactivity of an enzyme encapsulated in ZIF-8. The enzyme@MOF can maintain high activity when the encapsulation process is driven by rapid enzyme-triggered nucleation of ZIF-8. When the encapsulation is driven by slow coprecipitation and the enzymes are not involved in the nucleation of ZIF-8, enzy-me@MOF tends to be inactive owing to unfolding and competing coordination caused by the ligand, 2-methyl imidazole.T hese two embedding patterns can easily be controlled by chemical modification of the amino acids of the enzymes,modulating their biofunctionality.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.
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