Modification of PVDF membrane by post-modified NH2-MIL-88B(Fe) showing improved permeability and oil/water separation performance

• Published in: Journal of environmental chemical engineering Vol. 11; no. 3; p. 109621
• Main Authors: Shen, Shusu, Li, Honglin, Shen, Yang, Bai, Renbi, Zhang, Ganwei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-06-2023
• Subjects: Membrane modification; NH2-MIL-88B(Fe); Oil/water separation; Permeability; Polyvinylidene fluoride membrane; Oil/water separation; Permeability; NH2-MIL-88B(Fe); Polyvinylidene fluoride membrane; Membrane modification
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2023.109621

Metal organic frameworks (MOFs) possess excellent post-modification characteristics, high specific surface area, diversity of skeleton composition and pore tunability, have been increasingly applied in membrane modifications. In this work, NH2-MIL-88B(Fe) (NM88B) was first fixed onto polyvinylidene fluoride (PVDF) membrane by polyethyleneimine (PEI) through a vacuum-assisted self-assembly process, and the deposited NM88B was subsequently grafted with perfluoroalkyl polyethoxyacetic acid (FPEOAA) via a condensation reaction to realize the surface modifications. The modified membranes (named as N1Fx) showed improved hydrophilicity and underwater-oleophobicity. In addition, very high pure water flux (up to 9403 L‧m−2‧h−1) was obtained for the N1Fx membranes due to the high porosity of introduced NM88B. In the dead-end filtration experiments of n-hexadecane-water emulsion, the optimum membrane N1F20 showed a good oil rejection rate (98.3%) and high permeation flux (667 L‧m−2‧h−1) which is approximately seven times of the pure PVDF membrane, indicating that the surface-modified membranes had excellent permeability and good separation performance. Even after four filtration cycles of oil-water emulsion, the rejection rate maintained higher than 97%, showing good reusability. Furthermore, the study found that N1F20 had certain acid and alkaline resistance and great potential for engineering applications.
[Display omitted]
•Surface modified PVDF membrane is achieved by post-modified NM88B.•Modified membrane shows high pure water flux (9403 L‧m-2‧h-1‧bar-1).•Water contact angle reduces from 112.7° to 66.3°.•Membrane shows good oil rejection (>97%) and usability.