Zhaolong Wang,Jinsong Xiong,Yibo Liao,Mingzhu Xie,Dongsheng Yang,Ce Zhang,Yongping Chen,Zhigang Zou
Manipulation of bubbles underwater is attracting a wide range of interests due to the immense potential applications for industry, human health, etc. Inspired by superaerophilic legs of the water strider, a unique type of superaerophilic/aerophobic Janus membrane with precisely controllable geometric parameters and morphologies for unidirectional transportation of bubbles underwater is proposed and fabricated by projection micro-stereolithography (P μ SL) based 3D printing technique. The bionic Janus membranes possess different wettability on their two sides, which enables them stable and ultra-fast unidirectional bubbles transportation underwater. The superhydrophobic microholes forbid the water entering them but provide numerous gas channels, which is dominated by the superaerophilic coating (nano-SiO 2 ). Most significantly, we apply our bionic Janus membranes for the ultra-fast removal of hydrogen bubbles adhering to the copper cathode during the hydrogen evolution reaction (HER). The amazing performance of our 3D printed bionic Janus membranes promises applications in terms of ultra-fast unidirectional gas transportation underwater, such as fast gas–liquid separation, bubble collection, gas removal for chemical reaction, and so on.
Due to the prominent membrane interface effect micro-oil or micro-water droplets are easily fused with water or oil and are difficult to separate. The size of underwater/underoil droplets varies greatly, it needs a functional membrane for separating various oil–water mixtures. A novel bionic Janus membrane with a superhydrophobic spindle knots structure was prepared by a one-step dual-axis electrospinning technique. The Janus membrane relying on liquid unidirectional permeation achieves the separation of various oil–water mixtures including light/heavy oils-water, oil-in-water, and water-in-oil emulsions. Accordingly, it can be designed as an underoil diode water collector without any leakage. Importantly, the spindle knots absorb, transport and coalesce the micro-oil droplets into large oil droplets during separating oil-in-water emulsion, whereas it can repel water adhesion and allow oil spreading during separating water-in-oil emulsion. Thus, the spindle knots endow the ultra-high interface oil–water mixture, various emulsions separation efficiency (interface oil: >99.8 %, oil-in-water emulsion: 99.5 %, water-in-oil emulsion: 99.2 %), and excellent antifouling properties of Janus membranes for underwater oil and underoil water. This bionic Janus membrane presents a wide application in smart oil–water separation equipment, biomedical microreactors, and flotation filtration devices.
Yihang Zhang,Jing Guo,Fucheng Guan,Xuecui Song,Qiang Yang,Xinbin Ji,Zheng Li,Jing Tao
As more eco-friendly and economical choice for wet facial masks, dry facial masks have always had the problem of cumbersome application process and poor water retention property. In this study, based on the mechanism of directional water transport of Janus membrane and plant transpiration , the hydrophobic polylactic acid (PLA) nanofiber layer and the superhydrophilic guar gum (GG) nanofiber layer were prepared on both sides of the silk facial mask (SM) by electrospinning to obtain the guar gum-based bionic Janus directional water transport facial mask (G-DFM). The results showed that the directional water transport function improved the facial mask's water retention by 37 %, and the nicotinamide (NAM) encapsulated in the GG layer gave the facial mask excellent whitening and antibacterial properties . The GG layer could be directed to swell after absorbing water to form the “gel-like”, which ensured that the G-DFM could continue to release NAM during its work and would enhance the attachment between the G-DFM and the skin. G-DFM not only retained the advantages of SM but also expanded the functions that SM did not have, providing an idea for designing more practical and ideal facial masks in the future.
危险品化学品经营许可证（带存储）