Freezing of Nanofluid Droplets on Superhydrophobic Surfaces
Freezing of Nanofluid Droplets on Superhydrophobic Surfaces
复制标题
超疏水表面上纳米流体液滴的冻结
DOI：
10.1021/acs.langmuir.0c02432
复制
发表时间：
2020-11-03
期刊：
影响因子：
3.9
通讯作者：
Chen, Xuemei
中科院分区：
文献类型：
--
作者：
Li, Xiaoyang;Yu, Jie;Chen, Xuemei
近年来，液滴在超疏水冷表面上的冻结得到了广泛的研究。然而，以往的工作主要集中在研究水滴的冻结行为，很少有工作已经进行了研究纳米流体液滴在超疏水表面上的冻结动力学。本文对水和纳米流体液滴在不同粗糙度的超疏水表面上的冻结形态进行了比较和研究。纳米流体液滴经历了从球形到平坦平台形态的形状转变，不同于表现出尖锐尖点的冷冻水滴。冷冻纳米流体液滴的平坦平台的尺寸随着纳米颗粒浓度的增加而增加。利用COMSOL Multiphysics软件对冷冻过程中的形貌变化进行了分析。与冻结的水滴相比，更多的气泡被捕获在冻结的纳米流体液滴内，这可能归因于纳米流体液滴的快速冻结速度。这些结果可以为许多需要冷冻纳米流体液滴的应用提供重要的见解，例如材料固化，三维（3D）打印以及相变增强。
Droplet freezing on cold superhydrophobic surfaces has been studied extensively in recent years. However, previous works are mainly focused on studying water droplet freezing behavior; little work has been conducted to investigate the freezing dynamics of nanofluid droplets on superhydrophobic surfaces. In this work, freezing morphologies of water and nanofluid droplets on superhydrophobic surfaces with different roughnesses were compared and studied. The nanofluid droplets underwent a shape transition from spherical to flat plateau morphology, different from the frozen water droplets that exhibit a sharp cusp. The size of the flat plateau for the frozen nanofluid droplet increases with increasing nanoparticle concentration. The underlying mechanism of the morphology change during the freezing process was elucidated using COMSOL Multiphysics. Compared to the frozen water droplets, more air bubbles are trapped inside the frozen nanofluid droplets, which might be ascribed to the fast freezing speed of the nanofluid droplets. These results can provide important insights for many applications that require freezing of nanofluid droplets, such as material solidification, three-dimensional (3D) printing, as well as phase change enhancement.