极低表面张力液体高稳固性排斥表面的设计：纳米尺度效应突破两难困境

Super liquid-repellent surfaces that can repel all common liquids are a dream material and have tremendous application potential. High liquid repellency relies on surface microstructures to reduce solid-liquid interfacial contact fraction, while solid-liquid-gas interfacial robustness requires high solid-liquid interfacial contact density. This dilemma situation causes that no materials available can effectively repel liquids of extremely low surface tension (γ < 15 mN/m). Then comes a question: Can we develop an appropriate surface design strategy to overcome the dilemma between liquid repellency and interfacial robustness and to optimize both properties at the same time? Based on our preliminary theoretical analysis, we predict that by combining nanosize effect with doubly re-entrant structure it is possible to achieve both high contact angle and high interfacial robustness factor simultaneously. By combination of both theoretical and experimental approaches, this proposal plans to design surfaces with specific nanoscale structural units, and to investigate the effect of surface feature size and structure on their repellency towards liquids of extremely low surface tension, aiming to answer the key question whether it is possible to overcome the dilemma between liquid repellency and interfacial robustness by introducing nanoscale structure design. This project will reveal the nanosize effect and structure effect in solid’s repellency towards liquids of extremely low surface tension, and provide design guidelines and fabrication routes for super liquid-repellent surfaces with excellent interfacial robustness.

能阻止一切常见液体润湿的超级液体排斥表面是梦想材料，具有广阔应用前景。高液体排斥性依赖于表面结构来极小化固-液界面接触分数，而固-液-气三相界面稳固性则要求高的固-液界面接触密度，两者的矛盾导致了现有材料无法实现对极低表面张力液体(γ<15mN/m)的有效排斥。那么，能否通过表面设计突破液体排斥性和界面稳固性的两难困境，实现两种性能同时优化？基于初步理论分析，我们预测将纳米尺度效应与双内凹结构结合有望同时优化接触角和界面稳固因子，实现极低表面张力液体高稳固性排斥。本项目拟实验与理论结合，设计并制备具有不同纳米尺度双内凹结构基元的表面，系统调查基元尺寸及结构对极低表面张力液体排斥性的影响机制，旨在回答是否可通过纳米尺度的结构设计解决液体排斥性与界面稳固性二者矛盾这一关键科学问题。本项目将阐明固体对极低表面张力液体排斥作用的纳米尺度及结构效应，为获得高稳固性超级排斥材料提供科学依据和技术途径。

能够阻止不同表面张力液体润湿的液体排斥表面具有广阔应用前景。然而，高液体排斥性依赖于表面结构来极小化固-液界面接触分数，而三相界面稳固性则要求高的固-液界面接触密度，两者的矛盾导致了现有材料往往难以实现对低表面张力液体的高稳固性排斥，使其在高速液体撞击等场景下丧失液体排斥特性。如何通过表面设计突破液体排斥性和界面稳固性的两难困境，实现两种性能同时优化成为一个重要课题。本项目中，我们基于理论分析，提出了将纳米尺度效应与双内凹结构结合来同时优化接触角和界面稳固因子，从而实现低表面张力液体的高稳固性排斥。通过系统的实验探索，我们将Langmuir Blodgett自组装制备纳米掩模版与一系列微纳加工刻蚀技术结合，成功制备了纳米尺度双内凹结构表面。对纳米双内凹表面的性能调查表明，其对不同表面张力液体具有优良的液体排斥特性和界面稳固性。与前人报道的微米尺度双内凹表面相比，本项目制备的纳米双内凹表面界面稳固因子提升高达3个数量级。液滴撞击实验也证实了所制备纳米尺度双内凹表面相比于微米尺度双内凹表面在不同液体撞击下具有显著提升的界面稳固性，能在高速液体撞击过程中保持优异的斥液特性。项目的实施成功建立了纳米尺度双内凹结构表面的制备方法，并验证了低表面张力液体高稳固性排斥设计策略的可行性，为高速撞击或高压环境中低表面张力液体排斥表面的研发提供了重要参考。项目执行过程中，标注本项目资助在Advanced Materials, Research, Advanced Functional Materials, Advanced Science等国内外重要刊物发表论文13篇，授权发明专利2项。培养博士、硕士研究生10名，已毕业6名。