Ultrafast sorption of micro-oil droplets within water by superhydrophobic-superoleophilic conical micro-arrays
Ultrafast sorption of micro-oil droplets within water by superhydrophobic-superoleophilic conical micro-arrays
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DOI：
10.1016/j.seppur.2023.123651
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发表时间：
2023-03
影响因子：
8.6
通讯作者：
Yunyun Song;Xu Zhang;Jialei Yang;Zhongguo Zhang;Guang-Gui Cheng;Y. Liu;Guo-jun Lv;Zhao-Peng Yu-Zhao-P
中科院分区：
文献类型：
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作者：
Yunyun Song;Xu Zhang;Jialei Yang;Zhongguo Zhang;Guang-Gui Cheng;Y. Liu;Guo-jun Lv;Zhao-Peng Yu-Zhao-P
工业废水和采出水往往含有一定量的油滴，必须经过适当处理达到环保标准后才能排放，否则可能对海洋生物、生态环境和人类健康构成严重威胁。然而，由于在油-水界面处非常有限的密度梯度和复杂的界面结构，在微油滴存在下的油-水分离呈现出显著的挑战。为了解决这个问题，我们开发了一种具有锥形微阵列的超疏水-超亲油表面，以实现微油滴在水中的超快速吸附。微油滴从锥形微柱的顶端向底部定向迁移。在无外压条件下，0.2 μL的微油滴在锥形微柱上的运动速度可达14.5mm/s，油水分离效率可达99.99%。另外，由于重油和轻油的密度、重力和浮力的差异，对于0.2 μL的微油滴，氯仿的运动速度（11.5 mm/s）远快于正己烷（0.1 mm/s）。随着倾角的增大，正己烷的运动速度变快，氯仿的运动速度变慢。因此，微小油滴运动速度的较大差异有助于实现不同油相的分离。该工作为研制能有效回收多相混合物中油滴的水下装置提供了理论基础和技术支持。
Industrial wastewater and produced water, which often contains a certain amount of oil droplets, must be properly processed up to environmental standards before discharging, otherwise it could pose a serious threat to marine life, ecological environment, and human health. However, the oil–water separation in the presence of micro-oil droplets presents a significant challenge due to the very limited density gradient and complex interfacial structure at oil–water interfaces. To address this issue, we developed a superhydrophobic-superoleophilic surface with conical micro-arrays to realize ultrafast sorption of micro-oil droplets in water. The micro-oil droplets transport directionally from the apex to the bottom of the conical microcolumn. The movement velocity of the micro-oil droplet (0.2 μL) on the conical microcolumn is up to 14.5 mm/s and the oil–water separation efficiency reaches 99.99% without external pressure. Additionally, due to the difference in density, gravity, and buoyancy force in heavy and light oils, the movement velocity of Chloroform (11.5 mm/s) was much faster than N-hexane (0.1 mm/s) for the micro-oil droplet of 0.2 μL. With the increasing tilted angle the movement velocity of N-hexane becomes faster and Chloroform becomes slower. Thus, the large difference in movement velocity of micro-oil droplet is helpful to realize the separation of different oil phases. This work provides the theoretical basis and technical support to fabricate underwater apparatus that can efficiently recover oil droplets from a multiphase mixture.