Materials science, information science and life science are the three frontier sciences in the current technological revolution, and the surface interface of materials occupies an important position in material science.

What is surface interface? The object of surface interface research is an inhomogeneous system with heterogeneity, that is, there are two or more phases with different properties in the system. The editor of aluminate coupling agent tells us that the surface interface is the transition region from one phase to another. According to the different aggregation states of substances, the surface interface can usually be divided into the following five categories:

Solid-gas-liquid-gas-solid-liquid-liquid-liquid-solid-solid.

There is always a homogeneous system between gas and gas. Therefore, there is no surface interface. It is customary to call the solid-gas, liquid-gas transition area the surface, and the solid-liquid, liquid-liquid, solid-solid transition area called the interface.

In fact, there is no clear interface between the two phases. There is a gradual transition between the two phases. The structure, energy, and composition of the surface interface area show continuous gradient changes. Therefore, the surface interface is not a geometric plane. It is a quasi-three-dimensional region with a complex structure and a thickness of about several molecular lines. Therefore, the interface region is often treated as a phase or layer, called the interface phase or interface layer.

There are obvious differences between the surface of a material and its internal body. No matter in structure or chemical composition However, it is unbalanced, thus generating surface energy. For materials composed of different components, an interface can be formed between the components. A certain component may also be enriched on the surface interface of the material. Even a single-component material. Due to internal defects, such as dislocations, etc., or the difference in crystal state forms grain boundaries. It may also generate an interface inside. The surface interface of the material has a decisive influence on the overall performance of the material. The corrosion, aging, hardening, damage, stamping, coating, drying, compounding, etc. of the material are all closely related to the surface interface of the material. Therefore, it is of great significance to study the surface and interface phenomena of materials.