Toward controlling wetting hysteresis with nanostructured surfaces derived from block copolymer self-assembly
Toward controlling wetting hysteresis with nanostructured surfaces derived from block copolymer self-assembly
复制标题
利用嵌段共聚物自组装产生的纳米结构表面控制润湿滞后
DOI：
10.1088/1361-6528/ac7c24
复制
发表时间：
2022
期刊：
影响因子：
3.5
通讯作者：
Colosqui, Carlos E
中科院分区：
文献类型：
--
作者：
Al Hossain, Aktaruzzaman;Dick, Austin;Doerk, Gregory;Colosqui, Carlos E
通过嵌段共聚物（BCP）自组装合成纳米结构表面使得能够在数十纳米量级的尺寸范围内精确控制表面特征形状。这项工作研究了如何利用这种能力来控制润湿滞后和液体粘附力的基板进行化学老化和其固有的润湿性的变化。通过BCP自组装，我们在硅衬底上制造纳米结构化表面，其具有具有固定周期（52 nm）和两个不同高度（60和200 nm）的规则圆锥柱的六边形阵列，这导致纳米结构的显著不同的横向和顶部表面积。所制造的表面的润湿滞后的特征在于使用准静态条件下的力-位移测量，并在足够长的时间段内的基板化学和表面能，其特征在于由杨氏接触角，显着变化。实验结果和理论分析表明，控制纳米结构的横向和顶部面积不仅可以控制润湿滞后的程度，而且还可以使前进和后退接触角不易受化学老化的影响。这些结果可以帮助合理化的纳米结构表面的设计，用于不同的应用，如自清洁，增强传热，并在微/纳米流体装置的阻力减少。
The synthesis of nanostructured surfaces via block copolymer (BCP) self-assembly enables a precise control of the surface feature shape within a range of dimensions of the order of tens of nanometers. This work studies how to exploit this ability to control the wetting hysteresis and liquid adhesion forces as the substrate undergoes chemical aging and changes in its intrinsic wettability. Via BCP self-assembly we fabricate nanostructured surfaces on silicon substrates with a hexagonal array of regular conical pillars having a fixed period (52 nm) and two different heights (60 and 200 nm), which results in substantially different lateral and top surface areas of the nanostructure. The wetting hysteresis of the fabricated surfaces is characterized using force–displacement measurements under quasistaic conditions and over sufficiently long periods of time for which the substrate chemistry and surface energy, characterized by the Young contact angle, varies significantly. The experimental results and theoretical analysis indicate that controlling the lateral and top area of the nanostructure not only controls the degree of wetting hysteresis but can also make the advancing and receding contact angles less susceptible to chemical aging. These results can help rationalize the design of nanostructured surfaces for different applications such as self-cleaning, enhanced heat transfer, and drag reduction in micro/nanofluidic devices.