Asymmetric Surface Engineering for Janus Membranes

Abstract Janus membranes show great promise toward various applications and are undergoing a fast‐paced development in materials science. The asymmetric surface engineering on surface wettability, layer thickness, and pore structure enables Janus membranes with superiority in mass transport over conventional membranes. This review aims to provide an overview on the role of asymmetric surface engineering in membrane fabrication, structure control, and property tuning. The relationship between asymmetric surface engineering and performance optimization of Janus membranes is then elucidated based on an understanding of the underlying mass transport mechanism for target applications. Finally, current challenges in this field are highlighted, hopefully inspiring more researches to address the controllability and tunability of surface engineering for Janus membranes in future.