ReaxFF-Based Molecular Dynamics Simulation of Polymethylmethacrylate Surface Modification by ROS in Plasma

Polymethylmethacrylate (PMMA) is widely applied in electronic and power equipment because of its excellent insulating properties. Studies have shown that surface modification of PMMA by plasma grafting can improve the surface antistatic performance of the material, reduce the surface charge accumulation and prevent surface flashover. The modification of materials by cold atmospheric plasma (CAP) involves the interaction of comprehensive physicochemical factors, among which reactive oxygen species (ROS) play an important role. In this paper, the reactive force field (ReaxFF) was applied to study the related mechanism of modification triggered by three ROS (O, OH, and H
2
O
2
) at the atomic level. The results showed that PMMA molecule was oxidized and produced macromolecular radicals and oxygen-containing groups after ROS treatment. These products have active chemical properties because of their unpaired electrons, and other functional groups can be grafted on the surface of materials with these radicals and groups as active sites. The simulation study can provide reference for material modification by graft copolymerization to obtain functional surface according to the expected design.