Biomimetic Janus membrane with spongy channels for directional liquid transport

Abstract

Janus fiber membranes enable directional liquid transport (DLT) for oil-water separation and moisture management, yet conventional pore-channel designs offer limited efficiency. Herein, we have developed a groundbreaking Janus nanofiber structure inspired by the structural characteristics of plant leaves, specifically the pore gradient and liquid transport channels within leaves. An innovative intermediate buffer layer composed of a three-dimensional helical nanofiber membrane was introduced to boost porosity and horizontal interconnectivity. A dopamine-controlled regulation mechanism synergistically optimized the pore structure and wettability of this layer. The resulting Janus membrane exhibits a remarkable unidirectional transport index (1250%), a high oil-water separation efficiency (98.92%), and an ultra-high flux (13860.77 L·m⁻²·h⁻¹). Its integration with textiles demonstrates superior moisture and thermal management, confirming its versatility for applications in oil-water separation, industrial wastewater treatment, and high-performance functional garments.