Accelerated freezing due to droplet pinning on a nanopillared surface
Accelerated freezing due to droplet pinning on a nanopillared surface
复制标题
DOI：
10.1063/1.5048933
复制
发表时间：
2018-12
期刊：
影响因子：
1.6
通讯作者：
Rachel N. Bohm;M. R. Haque;C. Qu;E. Kinzel;A. Betz
中科院分区：
文献类型：
--
作者：
Rachel N. Bohm;M. R. Haque;C. Qu;E. Kinzel;A. Betz
冻结过程受环境因素和表面形貌的显著影响。在大气压下，对于给定的相对湿度，低于露点和冰点温度的表面在表面上不均匀地成核水滴，然后冻结。本文探讨了纳米结构表面上的成核，生长和随后的冻结过程的影响。微球光刻（MPL）用于图案化二氧化硅纳米柱阵列。该技术使用微球的自组装晶格将UV辐射聚焦到光致抗蚀剂中的光子射流阵列。使用电子束蒸发和剥离来沉积二氧化硅。将样品置于22±0.5°C的大气温度和40%或60%的相对湿度下的冷冻台上。纳米柱表面对液滴动力学和冷冻行为具有显著影响，与60%RH下的普通亲水表面相比，冷冻加速了一个数量级，其中冰桥需要覆盖更大的空隙以用于生长液滴内的冷冻前沿的传播。通过钉扎液滴，抑制纳米柱表面的聚结，改变液滴的尺寸分布并加速冷冻过程。影响凝固特性的主要机制是纳米柱表面的钉扎行为，凝固过程受环境因素和表面形貌的显著影响。在大气压下，对于给定的相对湿度，低于露点和冰点温度的表面在表面上不均匀地成核水滴，然后冻结。本文探讨了纳米结构表面上的成核，生长和随后的冻结过程的影响。微球光刻（MPL）用于图案化二氧化硅纳米柱阵列。该技术使用微球的自组装晶格将UV辐射聚焦到光致抗蚀剂中的光子射流阵列。使用电子束蒸发和剥离来沉积二氧化硅。将样品置于22±0.5°C的大气温度和40%或60%的相对湿度下的冷冻台上。纳米柱表面对液滴动力学和冻结行为有显着影响，与60%RH下的普通亲水表面相比，冻结加速了一个数量级，其中冰桥需要...
The freezing process is significantly influenced by environmental factors and surface morphologies. At atmospheric pressure, a surface below the dew and freezing point temperature for a given relative humidity nucleates water droplets heterogeneously on the surface and then freezes. This paper examines the effect of nanostructured surfaces on the nucleation, growth, and subsequent freezing processes. Microsphere Photolithography (MPL) is used to pattern arrays of silica nanopillars. This technique uses a self-assembled lattice of microspheres to focus UV radiation to an array of photonic jets in photoresist. Silica is deposited using e-beam evaporation and lift-off. The samples were placed on a freezing stage at an atmospheric temperature of 22±0.5°C and relative humidities of 40% or 60%. The nanopillar surfaces had a significant effect on droplet dynamics and freezing behavior with freezing accelerated by an order of magnitude compared to a plain hydrophilic surface at 60% RH where the ice bridges need to cover a larger void for the propagation of the freezing front within the growing droplets. By pinning droplets, coalescence is suppressed for the nanopillared surface, altering the size distribution of droplets and accelerating the freezing process. The main mechanism affecting freezing characteristics was the pinning behavior of the nanopillared surface.The freezing process is significantly influenced by environmental factors and surface morphologies. At atmospheric pressure, a surface below the dew and freezing point temperature for a given relative humidity nucleates water droplets heterogeneously on the surface and then freezes. This paper examines the effect of nanostructured surfaces on the nucleation, growth, and subsequent freezing processes. Microsphere Photolithography (MPL) is used to pattern arrays of silica nanopillars. This technique uses a self-assembled lattice of microspheres to focus UV radiation to an array of photonic jets in photoresist. Silica is deposited using e-beam evaporation and lift-off. The samples were placed on a freezing stage at an atmospheric temperature of 22±0.5°C and relative humidities of 40% or 60%. The nanopillar surfaces had a significant effect on droplet dynamics and freezing behavior with freezing accelerated by an order of magnitude compared to a plain hydrophilic surface at 60% RH where the ice bridges need t...