As one of the most commonly used inorganic nanomaterials, nano-silica (SiO2) has been widely concerned and applied by researchers in various fields. Nano-SiO2 has been used as the modified filler, its polymer nanocomposites combine the advantages of both polymer matrix and nano-SiO2, and thus show excellent mechanical properties, thermal properties, optical properties and chemical stability, etc. However, the surface of nano-SiO2 is rich in a large amount of active silicone hydroxyl, which is easy to aggregate. So, it's difficult to obtain uniform dispersion on the nanometer scale and good interfacial adhesion between nano-SiO2 and polymer matrix materials by general methods. Therefore, before the preparation of polymer-based nanocomposites modified by nano-SiO2, surface modification is required to improve the interfacial compatibility between SiO2 particles and polymer matrix and its dispersibility in the polymer matrix, and give it a certain degree of functionality. At present, there are many modification methods for nano-SiO2. In general, it is mainly physical modification and chemical modification, and according to different types of modified agents, it can be divided into organic modification, inorganic modification and hybrid modification. The excellent properties of polymer/nano SiO2 composites depend not only on the properties of the two components of organic polymer and inorganic nano-SiO2, but also on the interfacial structure and morphological characteristics between them. Although the volume content of interface phase is only a small part of total volume content, but the interaction between the interfaces, the differences between polymer structure and matrix structure at the interface, and the changes in the microstructure of interface phase and so on will significantly change the macro-performance of whole composite system. Therefore, the interface research between them has important scientific significance for the optimization design of nanocomposite properties. In recent years, the research of interface between polymer and inorganic nanoparticles mainly focused on two aspects. On the one hand, the physical and chemical properties of the surface of polymer and inorganic nanoparticles affect the properties at the interface. On the other hand, the interfacial interaction between polymer matrix and inorganic nanoparticles affects the properties of its composites. At present, the microstructure (such as roughness, thickness, etc.) and chemical structure (such as chemical bonding, bond energy, etc.) of the interface phase are often tested by modern instrumental analysis technology, or the molecular dynamics simulation is used to elucidate the molecular assembly structure and the mechanism of mutual interaction. Which can explain the interface performance and interface behavior more accurately from a theoretical perspective, and provide a theoretical basis and new methods for the optimal design of composites. In this paper, the research progress of organic modification, inorganic modification and hybrid modification on the functionalization of nano-SiO2 is summarized. The advantages and disadvantages of different modification methods are discussed and compared, and recent advances in the research of polymer/SiO2 interface in modern instrumental analysis characterization and molecular dynamics simulation are reviewed in detail. Finally, the future research focus of the interaction between nano-SiO2 and polymer matrix is forecasted. © 2019, Materials Review Magazine. All right reserved.
