在生活中，长期使用的玻璃表面会变得浑浊，这是由于液体在玻璃表面浸润的时候对玻璃表面造成的溶蚀。我们将溶解润湿定义为液体在可溶解表面铺展的现象。溶解润湿是页岩油气开采、金属 3D 打印、药物溶解、微纳加工等领域中的瓶颈问题之一。本文通过理论和实验相结合的方法对溶解润湿动力学中的三个关键科学问题：固液相互作用中的力化耦合、质量和动量的耦合输运、接触线失稳机理和判据开展研究。在实验上，将染色标定方法和 Particle Image Velocity方法结合发展了新的流场和浓度场同步观测方法；在理论上，考虑溶解和润湿的耦合发展了 Onsager 变分原理用于分析溶解润湿的动力学过程和接触线失稳。本文的主要的研究内容和成果如下:

力化耦合影响了液滴的铺展和界面的演化。扩散主导下液滴的铺展过程可以分为两个阶段，分别受界面张力主导和溶解能主导。接触线附近溶质和溶剂分子的结构和相互作用决定了溶解能的大小，利用分子动理论和变分原理，我们廓清了液滴半径随时间变化标度律的范围。另外，界面上分子结构的改变导致了界面张力梯度的产生，从而引发了两种不同的输运模式，即: “平移模式” 和 “抬升模式”。随着界面张力梯度的增大，溶坑的曲率逐渐增加。通过相图阐明了润湿和溶解对界面形状的影响，根据固液界面的几何形状，进而估算其形成的时间。

Marangoni 对流、自然对流和扩散三者之间的竞争产生了三种类型的溶解润湿。I 类：溶解润湿内部的动量和质量输运由扩散主导，溶剂和溶质的流动是从基底到液滴顶部；II 类：内部的动量和质量输运由 Marangoni 效应和扩散主导，在液滴内部形成一对涡流，刚溶解的溶质主要经由液气界面输运；首次发现了 III 类溶解润湿：溶解润湿需要考虑重力的影响，液滴中存在两对流向相反的涡流，而溶质的输运主要集中在液滴下半部分的自然对流中。我们提出了新的无量纲数用于阐明不同类型溶解润湿形成的条件。

表面张力和溶解能的竞争导致了塔型失稳 (Pagoda Instability)。这是一种新的失稳现象，液体沿可溶性纤维的表面爬升的过程中，接触线会发生失稳滑落，纤维最后被溶解成宝塔的形状。液体的爬升过程伴随着纤维的溶解，溶质分子进入液体后被溶剂壳包裹，改变了系统的化学能，影响了接触线的运动。界面张力和溶解能的竞争导致了接触线的失稳，纤维半径和接触线高度满足 2/3 的标度指数。通过塔型失稳制备的针尖具有低毛细吸附力的特征，可以被用于制备 AFM 探针或者低吸附力的表面，具有广阔的应用前景。

在生活中，长期使用的玻璃表面会变得浑浊，这是由于液体在玻璃表面浸润的时候对玻璃表面造成的溶蚀。我们将溶解润湿定义为液体在可溶解表面铺展的现象。溶解润湿是页岩油气开采、金属 3D 打印、药物溶解、微纳加工等领域中的瓶颈问题之一。本文通过理论和实验相结合的方法对溶解润湿动力学中的三个关键科学问题：固液相互作用中的力化耦合、质量和动量的耦合输运、接触线失稳机理和判据开展研究。在实验上，将染色标定方法和 Particle Image Velocity方法结合发展了新的流场和浓度场同步观测方法；在理论上，考虑溶解和润湿的耦合发展了 Onsager 变分原理用于分析溶解润湿的动力学过程和接触线失稳。本文的主要的研究内容和成果如下:

力化耦合影响了液滴的铺展和界面的演化。扩散主导下液滴的铺展过程可以分为两个阶段，分别受界面张力主导和溶解能主导。接触线附近溶质和溶剂分子的结构和相互作用决定了溶解能的大小，利用分子动理论和变分原理，我们廓清了液滴半径随时间变化标度律的范围。另外，界面上分子结构的改变导致了界面张力梯度的产生，从而引发了两种不同的输运模式，即: “平移模式” 和 “抬升模式”。随着界面张力梯度的增大，溶坑的曲率逐渐增加。通过相图阐明了润湿和溶解对界面形状的影响，根据固液界面的几何形状，进而估算其形成的时间。

Marangoni 对流、自然对流和扩散三者之间的竞争产生了三种类型的溶解润湿。I 类：溶解润湿内部的动量和质量输运由扩散主导，溶剂和溶质的流动是从基底到液滴顶部；II 类：内部的动量和质量输运由 Marangoni 效应和扩散主导，在液滴内部形成一对涡流，刚溶解的溶质主要经由液气界面输运；首次发现了 III 类溶解润湿：溶解润湿需要考虑重力的影响，液滴中存在两对流向相反的涡流，而溶质的输运主要集中在液滴下半部分的自然对流中。我们提出了新的无量纲数用于阐明不同类型溶解润湿形成的条件。

表面张力和溶解能的竞争导致了塔型失稳 (Pagoda Instability)。这是一种新的失稳现象，液体沿可溶性纤维的表面爬升的过程中，接触线会发生失稳滑落，纤维最后被溶解成宝塔的形状。液体的爬升过程伴随着纤维的溶解，溶质分子进入液体后被溶剂壳包裹，改变了系统的化学能，影响了接触线的运动。界面张力和溶解能的竞争导致了接触线的失稳，纤维半径和接触线高度满足 2/3 的标度指数。通过塔型失稳制备的针尖具有低毛细吸附力的特征，可以被用于制备 AFM 探针或者低吸附力的表面，具有广阔的应用前景。

In our daily life, the surface of glass used for a long time will become opacitas, because the liquid in the glass dissolves the surface of the glass when it wets on the surface. We define dissolutive wetting as the liquid wetting and dissolveing the substrate. Dissolutive wetting is a key problem in many fields, such as shale oil and gas exploitation, metal 3D printing, drug dissolution, micro-nano processing and so on. This paper studies three key scientific problems: the coupling of three-phase contact line moving and the dissolution of solid, coupling of mass and momentum transportation, and the mechanisms and criteria of contact line instability by theoretical and experimental methods. In experiments, we design the new mothod to obersve the flow field and concentration field synchronously. In theory, we develop Onsager variational principle by considering wetting and dissolution to study the dynamics and contact line instability of the dissolutive wetting. The main research contents and results of this paper are as follows:

The mechano-chemical coupling affects the spreading of the droplets and the evolution of interfaces.The moving of droplet can be divided into two stages, which are dominated by interfacial tension and solvation energy, respectively. The structure and interaction of solute and solvent molecules near the contact line and interface determine the solvation energy. Using the molecular dynamics theory and variational principle, the range of the scaling law for droplet radius changing with time is clarified. In addition, the change of molecular structure on the interface induces the occurence of interfacial tension gradient, which results in two different transport modes, namely “shifting mode” and “lifting mode”. With the increase of interfacial tension gradient, the curvature of the hole increases gradually. The influence of wetting and dissolution on the interface shape is illustrated by phase diagram, and the time of holes formation is estimated according to the interface shape.

The competition among Marangoni convection, natural convection, and diffusion produces three types of dissolutive wetting. The momentum and mass transport in I type is dominated by diffusion. The solvent and solute flow from the base to the top of the droplet. For II type, momentum and mass transport are dominated by the Marangoni effect and diffusion. There is a pair of eddy in the droplet, and the newly dissolved solute mainly transports along liquid-air interface. For the first time, we find the III type dissolutive wetting which needs to consider the influence of gravity. There are two vortexes with opposite directions, the solute transportation mainly occurs in the lower part of droplet, and we propose new dimensionless numbers to clarify the conditions of different types of dissolutive wetting.

The competition between surface tension and dissolution energy leads to Pagoda Instability. It is a new instability phenomenon in which fluid slides along the contact line after it rising along the surface of the soluble fiber, and the fiber is eventually dissolved into the shape of a Pagoda. The rise of the liquid is accompanied by the dissolution of the fiber. The solute molecules enter the liquid and are surrounded by the solvent shell, which changes the chemical energy of the system and affects the motion of the contact line. The competition between interfacial tension and dissolution energy results in the instability of the contact line. The fiber radius and the height of the contact line agree with the 2/3 scaling exponent. The tip prepared by pagoda instability has low capillary adhesion and can be used to prepare AFM probes or surfaces with low adhesion. The special tip has a broad application prospect.