Fu Changhui, Tian Guangyi, He Shiping, Yao Li, Guo Zhiguang
Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials, Hubei University, Wuhan 430062, People's Republic of China.
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
ACS Appl Mater Interfaces. 2024 Jul 24;16(29):37757-37769. doi: 10.1021/acsami.4c08781. Epub 2024 Jul 13.
Superwetting surfaces are often applied in oil/water separation. Hydrogels have been widely prepared as superhydrophilic/underwater superoleophobic materials for oil/water separation since they are naturally hydrophilic. Hydrogels usually need to be combined with porous substrates such as stainless steel mesh (SSM) due to their poor mechanical properties. However, it is usually inevitable that the pores of the substrate are clogged during the actual preparation process, leading to a significant decrease in the flux, which limits its effective application. In this study, acrylic acid (AA), chitosan (CS) and modified silica were utilized to form a layer of dual-network PAA/CS@SiO hydrogel by photopolymerization on SSM, followed by a simple and novel ultrasonic-assisted pore-making method to generate numerous pores in situ on the surface of the hydrogel-coated mesh, which led to an increase in water flux from 0 to 70,000 L m h without decreasing the separation efficiency. After 100 separations of a mixture of -hexane and water, the flux was still higher than 50,000 L m h with a separation efficiency above 99%, which is superior to most of hydrogel-coated meshes reported so far. Moreover, the prepared PAA/CS@SiO hydrogel-coated mesh also has good environmental stability, low swelling, and self-cleaning properties. We believe that the strategy of this study will provide a simple new perspective when hydrogels block the substrate pores, resulting in low water flux.
超润湿表面常用于油水分离。水凝胶因其天然亲水性，已被广泛制备为用于油水分离的超亲水/水下超疏油材料。由于水凝胶机械性能较差，通常需要与多孔基材如不锈钢网（SSM）结合使用。然而，在实际制备过程中，基材的孔隙通常不可避免地会被堵塞，导致通量显著下降，这限制了其有效应用。在本研究中，利用丙烯酸（AA）、壳聚糖（CS）和改性二氧化硅通过光聚合在SSM上形成一层双网络PAA/CS@SiO水凝胶，随后采用一种简单新颖的超声辅助造孔方法在水凝胶涂层网的表面原位产生大量孔隙，这使得水通量从0增加到70000 L m⁻² h⁻¹，同时不降低分离效率。对正己烷和水的混合物进行100次分离后，通量仍高于50000 L m⁻² h⁻¹，分离效率高于99%，这优于目前报道的大多数水凝胶涂层网。此外，制备的PAA/CS@SiO水凝胶涂层网还具有良好的环境稳定性、低溶胀性和自清洁性能。我们认为，当水凝胶堵塞基材孔隙导致水通量较低时，本研究的策略将提供一个简单的新视角。
