How do fluorine atoms improve the corrosion resistance of organic polysilazane?

In organic polysilazane, fluorine atoms mainly improve its corrosion resistance in the following ways:

Enhancing intermolecular forces

Fluorine atoms have extremely high electronegativity, being the most electronegative element among all. When introduced into the molecular structure of organic polysilazane, they enhance the intermolecular forces. Since the highly electronegative fluorine atoms attract the electron cloud, the charge distribution within the molecule becomes more uneven. This results in stronger electrostatic interactions, specifically an increase in the orientation force and induction force of the van der Waals forces. These stronger intermolecular forces cause the molecular chains of the material to bind more tightly, making it difficult for external corrosive substances to penetrate into the interior of the material, thereby improving the corrosion resistance of the material.

Improving chemical stability

Fluorine atoms form chemical bonds with atoms such as silicon and carbon with relatively high bond energies. For example, the bond energy of the carbon - fluorine bond (C - F) is much higher than that of common chemical bonds like the carbon - hydrogen bond (C - H). In organic polysilazane, the chemical bonds formed with the participation of fluorine atoms can stabilize the molecular structure. When facing corrosive media, it is more difficult for these chemical bonds to break and undergo chemical reactions, thus improving the chemical stability and corrosion resistance of the material.

Forming a dense protective film

Fluorine - containing groups tend to aggregate on the material surface. After the organic polysilazane is coated on the surface of an object, fluorine atoms tend to migrate to the material surface, forming a dense protective film rich in fluorine atoms. This protective film has an extremely low surface energy, which can prevent the adsorption and spreading of corrosive media such as water, acids, and alkalis on the material surface. By reducing the contact area between the corrosive media and the material, the possibility of corrosion is decreased. 分享 氟原子在有机聚硅氮烷中还能通过哪些方式提高其耐腐蚀性？