Reversibly Dispersible/Collectable Metal-Organic Frameworks Prepared by Grafting Thermally Responsive and Switchable Polymers

A reversibly dispersible/collectable metal-organic framework (MOF) system has been developed. The MOF particles were modified by grafting the thermally switchable copolymers of 2-(2-methoxyethoxy)ethyl methacrylate and oligo(ethylene glycol) methacrylate through a surface-initiated atom transfer radical polymerization (SI-ATRP) approach. The resulted MOF materials preserved their original framework structure and could be readily dispersed in water at room temperature to form stable dispersions. The dispersed MOF particles could also be recollected by heating the dispersions to above the lower critical solution temperature (LCST) of the grafted copolymer. The dispersion and collection processes were reversible.