液体在界面的亲疏界限，是界面浸润性领域最基本的科学问题之一，也是超浸润界面材料实现应用的重要基础。传统观点认为，在理想的平滑界面，根据杨氏方程，接触角为90度定义为所有液体的亲疏界限。杨氏方程是以表面能这一宏观的物理量为基础定义了亲疏液的界限，但液体在界面上的亲疏性质本质上应与分子间作用力相关。本项目拟利用原子力测量分子间作用力的方法，从分子尺度揭示不同液体的亲疏界限：即在液相环境中，通过测量修饰有功能分子的针尖和基底之间的相互作用力，当具有相同组成的针尖和基底之间的相互作用力表现为斥力时为亲液，表现为引力时为疏液，引力和斥力之间的转变点所对应的液体在基底的接触角数值定义为该液体的亲疏界限。进一步总结液体亲疏界限与表面能的规律，选择具有不同微纳米结构的体系进行验证，指导液体分子在微纳米体系内的可控传输。本项目的实施希望可以实现浸润性基础研究的突破，并能指导具有特殊浸润性的功能材料的设计。

The limitation of lyophilicity and lyophobicity at the interface is one of the most basic scientific problems in the field of wettability, and it is also an important basis for the application of super-wetting interface materials. According to the Young's equation, the traditional view is that the contact angle of 90 degrees is defined as the limitation of lyophilicity and lyophobicity of all liquids at the ideal smooth interface. The Young's equation defines the limitation of the lyophilicity and lyophobicity, which based on the macroscopic physical quantity of surface energy, but the lyophilicity and lyophobicity at the interface should be related to the intermolecular force. This project intends to use atomic force microscopy to measure intermolecular forces and reveal lyophilicity and lyophobicity of different liquids at the molecular scale: in the liquid environment, the interaction between the tip and the substrate modified with functional molecules is measured. The interaction force between the tip and the substrate with the same composition is lyophilic when the repulsive force is measured, and it is lyophobic when the attraction is measured. The value of the contact angle of the liquid at the transition point between the attractive and repulsive forces is defined as the limitation of lyophilicity and lyophobicity of the liquid. The rules of the lyophilicity and lyophobicity and liquid surface energy are further summarized, and systems with different micro-nano structures are selected for verification to guide the controllable transport of liquid molecules in the micro-nano system. The implementation of this project hopes to achieve breakthroughs in wettability basic research and to guide the design of functional materials with special properties.