将超疏水表面与莱登冻土的悬浮悬浮悬浮在热表面上徘徊而不是与之进行物理接触的水滴结合在一起 - 过去十年来，人们一直在广泛探索过，希望揭开水上依赖水的神圣的圣地。
在新的转折中，首尔国立大学和Dankook大学的一群韩国研究人员报告说，Leidenfrost Levitation在纳米叶片表面上产生的一种异常的水滴爆炸现象Applied Physics Letters.
“润湿性在确定平衡接触角，接触角滞后和固体之间的粘附方面起着关键作用surface液体和液体的缩回过程撞击了表面上的液滴。
非润湿表面往往be created by one of two methods. “First, textured surfaces enable nonwettability because a liquid can’t penetrate into the micro- or nano-features, thanks to air entrapment between asperities on the textured materials,” Lee said.
Or, second, the Leidenfrost effect “can help produce a liquid droplet dancing on a hot surface by floating it on a cushion of its own vapor,” he added. “The vapor film between the droplet and heated surface allows the droplet to bounce off the surface—also known as the ‘dynamic Leidenfrost phenomenon.'”
Lee and colleagues developed a special “nonwetting, nanotextured surface” so they could delve into the dynamic Leidenfrost effect’s impact on the material.
“Our nanotextured surface was verified to be ‘nonwetting’ via thermodynamic analysis,” Lee elaborated. “This analytical approach shows that the water droplet isn’t likely to penetrate into the surface’s nanoholes, which is advantageous for designing nonwetting, water-repellant systems. And the water droplet bouncing was powered by the synergetic combination of the nonwetting surface—often called a ‘Cassie surface’—and the Leidenfrost effect.”
通过比较疏水表面和纳米刺的表面，该小组发现增强的水滴弹跳是由Leidenfrost悬浮悬浮和无障碍的Cassie状态的综合影响产生的。
“A thermodynamic approach predicts the nonwettability on the nanotextured surface, and a scaling law between the capillary and vapor pressure of the droplet explains the mechanism of the dynamic Leidenfrost phenomenon,” said Lee.
这些发现应该“对于广泛的研究领域，例如通过Leidenfrost效应和纳米讲特征，增强的液滴弹跳以及在加热的Cassie表面上煮沸液滴的薄膜沸腾的特征，例如通过leidenfrost效应和纳米叶片的特征进行无损坏表面的研究有价值。”
值得注意的是，该小组的工作进一步发展了对疏水和纳米工程表面上动态的Leidenfrost液滴悬浮和液滴反弹现象的基本理解。这意味着它将用于为工业应用开发高度替水的表面，例如自我清洁的窗户，挡风玻璃，外部油漆，防污染涂料，屋顶瓷砖和纺织品。
Lee指出：“我们未来的工作将着重于使用微观和纳米级规律性开发多尺度结构，并以动态的Leidenfrost效应探索其表面的无障碍特征。”
Filed Under:工业自动化
