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

Authors：Dai, Tianliang; Wang, Lina; Yao, Juming; Zhu, Guocheng; Guo, Baochun; Militk, Jiri; Kremenakova, Dana; Zhang, Ming^*

Source：SEPARATION AND PURIFICATION TECHNOLOGY, 2024, 332: 125793.

DOI：10.1016/j.seppur.2023.125793

• Electrospinning
• Janus membrane
• Shish-kebab structure
• Water transport
• Emulsion separation

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 hy-drophilic 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 be-tween 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.