Simultaneous Realization of Superoleophobicity and Strong Substrate Adhesion in Water via a Unique Segment Orientation Mechanism
Danfeng Yu, Jianjia Huang, Zhenqiang Zhang, Jiahao Weng, Xiubin Xu, Guojie Zhang, Jianguo Zhang, Xu Wu, Melissa Johnson, Jing Lyu, Hui Yang, Wenxin Wang
The underwater superoleophobicity of a coating is often caused by its preferential water affinity, which, however, normally weakens the substrate adhesion property. In this work, a new strategy is reported for achieving strong underwater adhesion between a well-designed amphiphilic polyurethane coating and a diverse range of substrates while also rendering the coating surface's superoleophobicity. When the coating, which is a mixture of an amphiphilic polyurethane and a water miscible solvent, is immersed in water, the hydrophobic segments aggregate to orientate and pile along the surface of substrates via a segment orientation mechanism triggered by solvent exchange with water penetration to exert strong adhesion. At the same time, the hydrophilic segments will physically crosslink to form a hydrogel coating, endowing the substrate with underwater superoleophobicity. This work provides a facile, versatile, and scalable approach for the future design of superoleophobic coatings in a water environment.