Microfluidic reactors for the size-controlled synthesis of ZIF-8 crystals in aqueous phase

Zeolitic imidazolate framework (ZIF-8) crystals can be produced effectively via continuous processes using either a single water phase or a biphasic water/alkane flow in a three-dimensional rnicrochannel. ZIF-8 particles were characterized by SEM, TEM, XRD, BET and Raman spectroscopy. The microfluidic technology developed allows the fast synthesis (10 min) of ZIF-8 crystals over a wide size range (from ca. 300 to 900 nm) simply by varying the experimental parameters (flow rates, temperature,...), while maintaining the high specific surface of this material (ca. 1700 m(2). g(-1)) and the sodalite crystalline structure. The microfluidic processes developed operate in water between 25 and 100 degrees C and at atmospheric pressure and are therefore valuable alternatives for the environmentally friendly preparation of ZIF-8 particles. (C) 2017 Elsevier Ltd. All rights reserved.