Gong Cheng,Chao Sui,Weizhe Hao,Jiaxuan Li,Yushun Zhao,Linlin Miao,Guoxin Zhao,Junjiao Li,Yuna Sang,Chenxi Zhao,Lei Wen,Xiaodong He,Chao Wang
Vapor-driven smart Janus materials have made significant advancements in intelligent monitoring, control, and interaction, etc. Nevertheless, the development of ultrafast response single-layer Janus membrane, along with a deep exploration of the smart response mechanisms, remains a long-term endeavor. Here, the successful synthesis of a high-crystallinity single-layer Covalent organic framework (COF) Janus membrane is reported by morphology control. This kind of membrane displays superior mechanical properties and specific surface area, along with excellent responsiveness to CH 2 Cl 2 vapor. The analysis of the underlying mechanisms reveals that the vapor-induced breathing effect of the COF and the stress mismatch of the Janus structure play a crucial role in its smart deformation performance. It is believed that this COF Janus membrane holds promise for complex tasks in various fields.
Liu Chunhua,Peng Yun,Huang Conglin,Shang Jiaoping,Liu Guohua,Li Yibao
Janus membranes with superwetting play an important role in many fields, such as oil/water separation, unidirectional fluid transportation, microfluidic devices, intelligent ion valve, mass/heat transfer applications, etc. Although there has been some progress in the preparation of the Janus membranes with unidirectional penetration, it still remains a great difficulty for facile fabrication of two dimensional Janus membranes with a large pore structure and stable bubble unidirectional transport in the water. Herein, a signal-layer Janus membrane with superwetting is fabricated via the method of liquid-regulated hydrophobic modification strategy. The resultant Janus mesh achieves underwater unidirectional penetration. Namely, Underwater bubbles can pass unidirectionally from superhydrophobic side to hydrophilic side, but are blocked from passing through in the opposite direction. Thus, this Janus membrane with the unidirectional underwater bubbles penetration “diode” performance. We believe this work can promote the development of multi-dimensional Janus materials for fluid directional transport.