Shoji Eita, Hoshino Akira, Biwa Tetsushi, Kubo Masaki, Tsukada Takao, Tomai Takaaki, Adschiri Tadafumi
Department of Mechanical Systems Engineering, Tohoku University, Sendai, Miyagi 980-8579, Japan.
Department of Chemical Engineering, Tohoku University Sendai, Sendai, Miyagi 980-8579, Japan.
Langmuir. 2024 Dec 17;40(50):26509-26516. doi: 10.1021/acs.langmuir.4c03347. Epub 2024 Dec 2.
Wetting of nanofluids containing highly dispersed nanoparticles of single-nanometer size was investigated, as these nanoparticles can persist within a nanometer-scale liquid film near contact line, potentially causing significant changes in wetting characteristics. We discerned distinctive superspreading wetting, featured by temporal indices (0.29 to 0.46) in the relationship between contact radius and time. We employed a phase-shifting imaging ellipsometer to measure droplet shape, including the nanometer-scale liquid film and nanoparticle layer after drying. The liquid film shapes differed from pure liquids at micrometer-scale but not at nanometer-scale. Furthermore, surface tension measurements and substrate surface energy control contributed to unraveling these characteristics. These findings differentiated the observed superspreading wetting from the mechanisms proposed in existing studies of aqueous surfactant solutions.
对含有单纳米尺寸高度分散纳米颗粒的纳米流体的润湿性进行了研究，因为这些纳米颗粒可以在接触线附近的纳米级液膜中持续存在，这可能会导致润湿性特征发生显著变化。我们识别出了独特的超铺展润湿性，其特征在于接触半径与时间关系中的时间指数（0.29至0.46）。我们使用相移成像椭圆仪来测量液滴形状，包括干燥后的纳米级液膜和纳米颗粒层。液膜形状在微米尺度上与纯液体不同，但在纳米尺度上没有差异。此外，表面张力测量和基底表面能控制有助于揭示这些特性。这些发现将观察到的超铺展润湿性与现有水性表面活性剂溶液研究中提出的机制区分开来。
