Screen printing directed synthesis of covalent organic framework membranes with water sieving property

Screen printing is introduced to direct the synthesis of crack-free and thickness-tunable TpPa(OH) 2 covalent organic framework membranes. A smooth precursor layer is firstly screen printed and then fully crystallised into the TpPa(OH) 2 membrane. Molecular-scale pores endow the membrane with a fast water-sieving property, which is promising in water desalination. An effective approach of screen printing has been developed to direct the synthesis of continuous COF membranes. The prepared membranes exhibit fast and selective water permeation properties.