Whether membranes developed for organic solvent nanofiltration (OSN) tend to be hydrophilic or hydrophobic? ── a review

Yi-Hao Tong; Li-Han Luo; Rui Jia; Rui Han; Sun-Jie Xu; Zhen-Liang Xu

doi:10.1016/j.heliyon.2024.e24330

Whether membranes developed for organic solvent nanofiltration (OSN) tend to be hydrophilic or hydrophobic? ── a review

Heliyon. 2024 Jan 12;10(2):e24330. doi: 10.1016/j.heliyon.2024.e24330. eCollection 2024 Jan 30.

Authors

Yi-Hao Tong¹, Li-Han Luo¹, Rui Jia¹, Rui Han¹, Sun-Jie Xu^{2

1

3}, Zhen-Liang Xu^{1

3}

Affiliations

¹ State Key Laboratory of Chemical Engineering, Membrane Science and Engineering R&D Lab, Chemical Engineering Research Center, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
² School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
³ Shanghai Electronic Chemicals Innovation Institute, East China University of Science and Technology, Shanghai 200237, China.

Abstract

In the past few decades, organic solvent nanofiltration (OSN) has attracted numerous researchers and broadly applied in various fields. Unlike conventional nanofiltration, OSN always faced a broad spectrum of solvents including polar solvents and non-polar solvents. Among those recently developed OSN membranes in lab-scale or widely used commercial membranes, researchers preferred to explore intrinsic materials or introduce nanomaterials into membranes to fabricate OSN membranes. However, the hydrophilicity of the membrane surface towards filtration performance was often ignored, which was the key factor in conventional aqueous nanofiltration. The influence of surface hydrophilicity on OSN performance was not studied systematically and thoroughly. Generally speaking, the hydrophilic OSN membranes performed well in the polar solvents while the hydrophobic OSN membranes work well in the non-polar solvent. Many review papers reviewed the basics, problems of the membranes, up-to-date studies, and applications at various levels. In this review, we have focused on the relationship between the surface hydrophilicity of OSN membranes and OSN performances. The history, theory, and mechanism of the OSN process were first recapped, followed by summarizing representative OSN research classified by surface hydrophilicity and types of membrane, which recent OSN research with its contact angles and filtration performance were listed. Finally, from the industrialization perspective, the application progress of hydrophilic and hydrophobic OSN membranes was introduced. We started with history and theory, presented many research and application cases of hydrophilic and hydrophobic OSN membranes, and discussed anticipated progress in the OSN field. Also, we pointed out some future research directions on the hydrophilicity of OSN membranes to deeply develop the effect made by membrane hydrophilicity on OSN performance for future considerations and stepping forward of the OSN industry.

Keywords: Hydrophilic; Hydrophobic; Industrial application; Organic solvent nanofiltration (OSN).

Publication types

Review