Wu Mingming, Shi Guogui, Liu Weimin, Long Yifei, Mu Peng, Li Jian
Key Laboratory of Eco-Functional Polymer Materials of the Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, P. R. China.
School of Materials Science and Hydrogen Energy, Foshan University, Foshan 528000, P. R. China.
ACS Appl Mater Interfaces. 2021 Mar 31;13(12):14759-14767. doi: 10.1021/acsami.1c02187. Epub 2021 Mar 22.
There are some methods to prepare superwetting surfaces with underwater superoleophobicity (UWSOB) or underoil superhydrophobicity (UOSHB), but it is still thorny to put forward a universal strategy for constructing dual superlyophobic surfaces in oil-water systems due to a thermodynamic contradiction. Herein, a universal strategy was proposed to prepare the dual superlyophobic surfaces in oil-water systems only via delicately controlling surface chemistry, that is, adjusting the ratios of superhydrophilic and superhydrophobic counterparts in the spray solution. Three types of materials, attapulgite (APT), TiO, and loess, were chosen to prepare a diverse series of mixed coatings (mass gradient of superhydrophobic counterparts from 0 to 100 wt %). With the proportion of each superhydrophobic counterpart increasing, the underwater oil contact angle (θ) of each mixed coating slightly decreased but still was more than 150°, that is, UWSOB. In contrast, the underoil water contact angle (θ) was significantly improved, realizing the transformation from UOHL (or UOHB) to UOSHB. More importantly, the respective mass ratios of superhydrophobic counterparts in the resulting mixed coatings of APT, TiO, and loess were finally determined to be 0.3, 0.4, and 0.2, respectively. Taking APT as a model, a train of mixed APT coatings with different superhydrophobic components were systematically characterized and analyzed. Finally, the prepared superlyophobic separation mesh in oil-water systems was applied to the separation of various surfactant-stabilized oil-water emulsions. We envision that this universal strategy we proposed will show a significant application potential in addressing scientific and technological challenges in the field of interfacial chemistry such as oil-water separation, microfluidics, microdroplet manipulation, antifogging/icing, cell engineering, drag reduction, and so forth.
有一些制备具有水下超疏油性（UWSOB）或油下超疏水性（UOSHB）超润湿表面的方法，但由于热力学矛盾，提出一种在油水体系中构建双超疏表面的通用策略仍然很棘手。在此，提出了一种仅通过精细控制表面化学来制备油水体系中双超疏表面的通用策略，即调整喷雾溶液中超亲水和超疏水成分的比例。选择了三种材料，凹凸棒石（APT）、TiO和黄土，制备了一系列不同的混合涂层（超疏水成分的质量梯度从0到100 wt%）。随着每种超疏水成分比例的增加，各混合涂层的水下油接触角（θ）略有下降，但仍大于150°，即UWSOB。相反，油下水接触角（θ）显著提高，实现了从UOHL（或UOHB）到UOSHB的转变。更重要的是，最终确定在所得的APT、TiO和黄土混合涂层中，超疏水成分各自的质量比分别为0.3、0.4和0.2。以APT为模型，系统地表征和分析了一系列具有不同超疏水成分的APT混合涂层。最后，将制备的油水体系超疏分离网应用于各种表面活性剂稳定的油水乳液的分离。我们设想，我们提出的这种通用策略将在解决界面化学领域的科学技术挑战方面展现出巨大的应用潜力，如油水分离、微流体、微滴操纵、防雾/防冰、细胞工程、减阻等等。
