Department of Mechanical Engineering, The University of Hong Kong , Pokfulam, Hong Kong.
HKU-Zhejiang Institute of Research and Innovation (HKU-ZIRI) , Hangzhou 311300, Zhejiang, China.
ACS Appl Mater Interfaces. 2018 Jan 24;10(3):3029-3038. doi: 10.1021/acsami.7b14453. Epub 2018 Jan 10.
The maneuver of small bubbles in a programmed way will advance numerous processes, including gas evolution reaction and aeration. Unlike in-air droplets, rapidly rising bubbles in liquid medium can hardly be steered through interaction with solid substrates, causing difficulties in maneuvering bubbles. We pattern and lubricate nanoporous substrates with regions of contrasting wettability that is similar to the back of Namib desert beetles and subsequently immerse the lubricated surface underwater to spontaneously form spatially patterned Nepenthes-inspired slippery surfaces after the dewetting of lubricants. As a result, bubbles are confined on lubricant-infused surfaces, with their high mobility well preserved. The interfacial states of attached bubbles are analyzed, and their dynamic sliding velocities are quantified. Using the lubricated patterned surfaces, we further demonstrate the predefined motion of bubbles driven by buoyancy at a small tiling angle, as well as a self-propulsion of bubbles driven by surface tension force at a tilting angle of 0°, respectively. The spatially lubricated surfaces simplify gas handling in liquid medium and have potential applications in fields where bubble handling is crucial.
通过编程控制小气泡的运动将推进众多过程，包括气体释放反应和曝气。与空气中的液滴不同，在液体介质中快速上升的气泡很难通过与固体基底的相互作用来控制，这给气泡的控制带来了困难。我们通过图案化和润滑具有对比润湿性的纳米多孔基底，其类似于纳米比亚沙漠甲虫的背部，随后将润滑表面浸入水下，在去润湿润滑剂后，自然形成空间图案化受猪笼草启发的滑溜表面。结果，气泡被限制在注满润滑剂的表面上，其高迁移率得到很好的保留。分析了附着气泡的界面状态，并对其动态滑动速度进行了量化。使用润滑图案化表面，我们进一步演示了在小倾斜角度下由浮力驱动的气泡的预定运动，以及在 0°倾斜角度下由表面张力驱动的气泡的自推进。空间润滑表面简化了液体介质中的气体处理，在气泡处理至关重要的领域有潜在的应用。
