PVP-assisted synthesis of monodisperse UiO-66 crystals with tunable sizes

A polyvinylpyrrolidone (PVP)-assisted synthesis method was reported to prepare monodisperse UiO-66 octahedral crystals with tunable sizes. In this acetic acid/PVP co-modulated synthesis system, the relatively weak coordination of PVP to Zr(IV) played an important role in manipulating the sizes of UiO-66 crystals instead of their shapes. With the optimized PVP concentrations, sizes of the monodisperse UiO-66 crystals could be effectively tuned from ~ 1900 nm to ~ 700 nm. These uniform MOF crystals could be assembled into monolayers on water surface and further transferred onto a solid substrate to yield MOF films with preferential orientation and controlled thicknesses.