High-performance polyethyleneimine based reverse osmosis membrane fabricated via spin-coating technology

• Published in: Journal of membrane science 2023-02, Vol.668, p.121248, Article 121248
• Main Authors: Xie, Tengteng, Wang, Hao, Chen, Kuo, Li, Feiyang, Zhao, Shengchao, Sun, Haixiang, Yang, Xiujie, Hou, Yingfei, Li, Peng, Niu, Q. Jason
• Format: Article
• Language: English
• Subjects: Antifouling; Multilayer interfacial polymerization; Reverse osmosis; Spin-coating
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2022.121248

Conventional thin-film composite (TFC) reverse osmosis (RO) membranes prepared by ultrafast and uncontrolled interfacial polymerization (IP) generally have unsatisfactory permeability and high fouling propensity, which distinctly impedes their development and wide application. Controllable thickness and roughness offer an opportunity to optimize the permeability and fouling resistance of RO membranes. In this work, we propose spin-coating assisted multilayer interfacial polymerization (SMIP) as a promising approach to fabricating high-performance RO membranes using polyethyleneimine (PEI) and 1, 3, 5-benzoyl chloride (TMC). SMIP integrates the high efficiency and uniformity of spin-coating technology, the nano-level and individual properties control of multilayer interfacial polymerization, and the simplicity of the IP process. Combining the strong hydrophilicity with low diffusion efficiency and positive charge of PEI, a thin, intrinsically hydrophilic, smoother and almost electro-neutral polyamide (PA) nanofilm was obtained. The optimal RO membrane with a controlled thickness of the selective layer (≈61 nm) has a water permeance of 3.12 L m−2 h−1 bar−1 and an acceptable NaCl rejection of 97.5%, while the strong hydrophilicity, minimal surface roughness and almost neutral surface charge afford it excellent fouling resistance. SMIP technology not only provides a new approach to preparing highly permeable and low-fouling RO membranes using macromolecular monomers, but also has great application potential in other separation membranes due to its precise control of the selective layer. [Display omitted] •A novel RO membrane was fabricated by spin-coating assisted multilayer interfacial polymerization (SMIP) with PEI and TMC.•The prepared RO membrane featured controllable thickness, minimal surface roughness and electro-neutral surface at pH 6–7.•Molecular simulation results showed that the SMIP increased the cross-linkage of the polyamide layer.•The RO membrane exhibited high permeability and excellent antifouling properties.•SMIP provides an approach for the controllable preparation of high-performance RO membranes.