Substitutional reaction in Si–O network of molecular dynamics‐modeled liquid Na₂SiO₃: Microscopic and statistical study

Abstract

The study of the bond breaking and formation processes, that is, the chemical reaction, in the Si–O network structure in liquid alkali silicates at temperatures around or higher than the glass‐transition temperature is important for understanding kinetic processes such as the structural relaxation of the network, viscous flow, and diffusion of the network former ions. Herein, novel methods for analyzing the reactions in a molecular‐dynamics‐modeled liquid Na2SiO3 were used to confirm the following results: (a) the substitutional reactions (in which a nonbridging O ion of a Si–O chain or a SiO4 tetrahedron attacks the Si ion of another chain from backside of a bridging O ion, which acts as the leaving group, and the bridging O leaves the Si ion) primarily occur in the Si–O network of liquid Na2SiO3; and (b) The abundance ratio of Qn species can be quantitatively reproduced by the reaction rate.