Periodic Parallel Array of Nanopillars and Nanoholes Resulting from Colloidal Stripes Patterned by Geometrically Confined Evaporative Self-Assembly for Unique Anisotropic Wetting
Periodic Parallel Array of Nanopillars and Nanoholes Resulting from Colloidal Stripes Patterned by Geometrically Confined Evaporative Self-Assembly for Unique Anisotropic Wetting
复制标题
由几何限制蒸发自组装形成的胶体条纹产生的周期性平行阵列纳米柱和纳米孔，以实现独特的各向异性润湿
DOI：
10.1021/am505835z
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发表时间：
2014-11-26
影响因子：
9.5
通讯作者：
Wang, Li
中科院分区：
文献类型：
--
作者：
Li, Xiangmeng;Wang, Chunhui;Wang, Li
在本文中，我们提出了一种经济的方法来创建基于周期性平行条纹的单层二氧化硅纳米粒子（NPs）的几何限制蒸发自组装（GCESA）图案的各向异性微纹理。在GCESA过程中，胶体分散的直半月板最初在一个开放的外壳中形成，该外壳由两个平行板组成，三个侧面由u形间隔侧壁隔开，第四个侧面有蒸发出口。胶体分散的侧向蒸发导致半月板（蒸发锋）的周期性“粘滑”后退，由“咖啡环”效应触发，促进二氧化硅NPs组装成周期性平行条纹。条纹的形态可以通过裁剪工艺变量如衬底润湿性、NP浓度、温度和间隙高度等来很好地控制。此外，利用制备的胶体条纹作为蚀刻掩膜或模板，在硅片上生成纳米柱或纳米孔的排列图案。这种排列模式可以显示出独特的各向异性润湿特性，在平行和垂直方向上都具有较大的接触角滞后，并且具有较大的润湿各向异性。
In this paper we present an economical process to create anisotropic microtextures based on periodic parallel stripes of monolayer silica nanoparticles (NPs) patterned by geometrically confined evaporative self-assembly (GCESA). In the GCESA process, a straight meniscus of a colloidal dispersion is initially formed in an opened enclosure, which is composed of two parallel plates bounded by a U-shaped spacer sidewall on three sides with an evaporating outlet on the fourth side. Lateral evaporation of the colloidal dispersion leads to periodic "stick-slip" receding of the meniscus (evaporative front), as triggered by the "coffee-ring" effect, promoting the assembly of silica NPs into periodic parallel stripes. The morphology of stripes can be well controlled by tailoring process variables such as substrate wettability, NP concentration, temperature, and gap height, etc. Furthermore, arrayed patterns of nanopillars or nanoholes are generated on a silicon wafer using the as-prepared colloidal stripes as an etching mask or template. Such arrayed patterns can reveal unique anisotropic wetting properties, which have a large contact angle hysteresis viewing from both the parallel and perpendicular directions in addition to a large wetting anisotropy.