Choi Jung Won, Ham Daseul, Han Seonghyun, Noh Do Young, Kang Hyon Chol
School of Materials Science and Engineering and Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
Department of Materials Science and Engineering, Chosun University, Gwangju 61452, Korea.
Nanomaterials (Basel). 2021 Jan 20;11(2):268. doi: 10.3390/nano11020268.
Liquid drops on deformable soft substrates exhibit quite complicated wetting behavior as compared to those on rigid solid substrates. We report on a soft wetting behavior of Co nanoparticles (NPs) on a sapphire substrate during pulsed laser-induced dewetting (PLID). Co NPs produced by PLID wetted the sapphire substrate with a contact angle near 70°, which is in contrast to typical dewetting behavior of metal thin films exhibiting contact angles greater than 90°. In addition, a nanoscale γ-AlO wetting ridge about 15 nm in size and a thin amorphous AlO interlayer were observed around and beneath the Co NP, respectively. The observed soft wetting behavior strongly indicates that the sapphire substrate became soft and deformable during PLID. Moreover, the soft wetting was augmented under PLID in air due to the formation of a CoO shell, resulting in a smaller contact angle near 30°.
与刚性固体基底上的液滴相比，可变形软基底上的液滴表现出相当复杂的润湿行为。我们报道了脉冲激光诱导去湿（PLID）过程中钴纳米颗粒（NPs）在蓝宝石基底上的软润湿行为。PLID产生的Co NPs以接近70°的接触角润湿蓝宝石基底，这与表现出大于90°接触角的金属薄膜的典型去湿行为形成对比。此外，在Co NP周围和下方分别观察到尺寸约为15 nm的纳米级γ-AlO润湿脊和薄的非晶AlO中间层。观察到的软润湿行为强烈表明，蓝宝石基底在PLID过程中变得柔软且可变形。此外，由于形成了CoO壳，在空气中的PLID作用下软润湿增强，导致接触角更小，接近30°。
