Metal‐Organic Framework Nanoparticles with Universal Dispersibility through Crown Ether Surface Coordination for Phase‐Transfer Catalysis and Separation Membranes

Abstract Dispersing metal‐organic framework (MOF) solids in stable colloids is crucial for their availability and processibility. Herein, we report a crown ether surface coordination approach for functionalizing the surface‐exposed metal sites of MOF particles with amphiphilic carboxylated crown ether (CE C ). The surface‐bound crown ethers significantly improve MOF solvation without compromising the accessible voids. We demonstrate that CE C ‐coated MOFs exhibit exceptional colloidal dispersibility and stability in 11 distinct solvents and six polymer matrices with a wide range of polarities. The MOF‐CE C can be instantaneously suspended in immiscible two‐phase solvents as an effective phase‐transfer catalyst and can form various uniform membranes with enhanced adsorption and separation performance, which highlights the effectiveness of crown ether coating.