In-situ growing ZIF-8 on cellulose nanofibers to form gas separation membrane for CO2 separation

ZIF-8@cellulose nanofiber (ZIF-8@CNF) composite membranes were prepared via in-situ growing ZIF-8 crystals on cellulose nanofibers (CNFs) and vacuum filtration. Owning to the electrostatic forces between -COO- of CNFs and Zn2+ of ZIF-8, ZIF-8 crystals were anchored homogenously on CNFs. With ZIF-8 loading increased to sufficiently high, the intrinsic selectivity of ZIF-8 played an important role for gas separation. As a result, the optimum separation performance is achieved over ZIF-8@CNF-70 composite membrane with CO2 permeability of 550 Barrer and CO2/N-2 and CO2/CH4 ideal selectivity of 45.5 and 36.2, respectively.