Synthesis And Characterization Of The GA/MOF/PPy Coated Nanofiltration Membrane

To lessen the water scarcity is a big challenge faced by separation technology around the world,to date,several advancements have been carried out in purification technology to remove the emerging contaminants from aqueous media.Among the membrane separation technologies,nanofiltration（NF）is widely used in purification of water,foodstuffs,dye removal and desalination.In order to optimally utilize the inherent potential of NF membrane,some achievements have been made in the research of thin film composites.Therefore,based on the existing research,it is of practical significance to explore more excellent membrane materials for the higher needs in the industry.Recently,the rapid development of bio-inspiring materials assisted techniques in the membrane separation field has attracted the great attention.Because of their unique efficiency,they are widely used to restrain the instinctual dimensions and characteristics of various organic-inorganic materials,such as nanomaterials,MOFs,and COFs.In this thesis,a novel strategy is revealed to construct nanoscale porous thin film composite TFC NF membrane with an efficient performance via the dip-coating method.In which zeolitic imidazolate framework（ZIF-67）with gallic acid material（GA）was used as a sacrificial model.Herein,the pyrrole polymerization reaction is carried out on membrane layer which made of gallic acid and ZIF-67 nanoparticles,meanwhile the polypyrrole reaction,ZIF-67 nanoparticles readily dissolve into water and leave a nanoscale porous structure and form a nanoscale porous thin film membrane layer GA/ZIF-67/PPy.This work showed strong mechanical integrity and antifouling property with high performance,exclusively based on steric-hindrance principle.Whereas the chemical composition,surface morphology,surface elemental composition,crystallinity and wettability of GA/ZIF-67/PPy TFC nanofiltration membranes is characterized by FTIR,SEM,XPS,XRD,and WCA.The NF performance of as-prepared membrane showed the rejection rates up to 98.53%,98.7%,99.19%,and 80.2%for RB（973.67 Da）,MB（799.80 Da）,CR（696.7 Da）,and BTB（624.3 Da）dyes along with permeances up to 14.76,12.07,12.57,and 9.98 L h^-1 m^-2bar^-1 respectively.