Self-induced crystallization to form a shish-kebab structure on PLA-based Janus membrane to promote water transmission and interlayer binding force

Janus membranes are widely used in fields such as oil-water separation and wound dressings due to their asymmetric wetting properties. However, the weak interface binding force between the hydrophobic and hydrophilic layers can affect the liquid transport performance and membrane separation. In this study, we have reported a method using self-induced crystallization to grow shish-kebab (SK) structures in electrospinning polylactic acid-based fiber membranes. Peel testing revealed that the peel load after induced crystallization increased from 0 to 0.05 N to 0.05–0.15 N, and the time for droplets to penetrate from the hydrophobic side to the hydrophilic side decreased from 16S to 3S. This indicates that SK structures can enhance the adhesion between the hydrophilic and hydrophobic interface, as well as facilitating droplet transport. Through the oil-water separation experiment, it was discovered that the presence of SK structures can filter out more microemulsions. For different emulsions (kerosene, petroleum, n-hexane, petroleum ether, tea tree oil), the separation efficiency of Janus-SK membrane increased by 1.67 %, 2.5 %, 3.0 %, 9.7 %, 4.3 %, respectively. The development of Janus membranes has been provided with a new direction.