Supramolecular recognition PVDF/PVA ultrafiltration membrane for rapid removing aromatic compounds from water

Water is very important for human survival. Economic and industrial development has caused urgent water pollution problems, especially pollution of water with aromatic compounds, which adversely affects human health. In this study, the polyvinylidene fluoride (PVDF) ultrafiltration membrane with the ability to remove aromatic compounds from water was developed. The supramolecular recognized PVDF/polyvinyl alcohol (SPVDF/PVA) ultrafiltration membrane that could remove aromatic compounds from water was obtained by firstly introducing reactive groups on the surface of PVDF ultrafiltration membranes through polymer/non-solvent co-induced phase separation, and then grafting hydroxypropyl-β-cyclodextrin on the membrane surface using chemical modification. The removal of aromatic compounds by the SPVDF/PVA ultrafiltration membrane mainly satisfied the Langmuir isothermal model and the pseudo-second-order kinetic equation. Density functional theory suggested that the SPVDF/PVA ultrafiltration membrane removed aromatic compounds by size matching and electrostatic attraction. The SPVDF/PVA ultrafiltration membrane exhibited hierarchical filtration characteristics when removing mixed solutions of proteins and aromatic compounds, with proteins removed by sieving and aromatic compounds removed by supramolecular recognition. Meanwhile, in the presence of various aromatic compounds, the SPVDF/PVA ultrafiltration membrane showed strong supramolecular recognition of phenolphthalein with a removal rate of 100%. In addition, the SPVDF/PVA ultrafiltration membrane had good reusability, with the regeneration rate remaining at 80% after 10 cycles. This study provided a reference for the removal of aromatic compounds from water by separation membranes and contributed a new idea for the preparation of novel functionalized separation membranes.