Preparation of hydrophilic modified ZIF-8 and its application in the preparation of nanocomposite matrix reverse osmosis membrane with improved permeation performance

Metal–organic frameworks (MOFs) are widely employed in designing nanocomposite membranes owing to their excellent performance and diversity. However, their inherent hydrophobicity limits their application in nanocomposite membranes. In order to improve the hydrophilicity of zeolitic imidazolate framework-8 (ZIF-8), tannic acid (TA) was utilized to etch-modify it, resulting in a TA-ZIF-8 nanostructure with a hydrophilic shell. TA-ZIF-8 was subsequently introduced into the aqueous phase and used to prepare a nanocomposite matrix reverse osmosis membrane through interfacial polymerization (IP). The prepared nanocomposite reverse osmosis membrane had a surface with good hydrophilicity and a pure water flux increased to 55.28 L m−2 h−1 (approximately 1.74 times). Additionally, the introduction of TA-ZIF-8 significantly enhanced the electronegativity of the membrane surface, and the nanoparticles were compatible with the polyamide layer, leading to a salt rejection rate of up to 99.5% for a NaCl solution with a concentration of 32000 ppm. These results indicate great potential for applying hydrophilically modified ZIF-8 to reverse osmosis membranes.