Insights into structure and properties of P2O5-based binary systems through molecular dynamics simulations

In order to clarify the microscopic characteristics and evolution rules of varying P2O5-based binary melt structures, molecular dynamics simulation (MD) was utilized to conduct a comprehensive study on its structure and performance. The investigation results demonstrated that the basic unit of P2O5-based binary melt network structure is [PO4](3-), and its structure is close to the standard tetrahedron. With the increase of P2O5 content, Q(0), Q(1) and Q(2) will gradually shift to Q(3) structure, resulting the network structure of each phosphate system more complicated. For a given P2O5 content in different systems, as the size of the metal cation decreases, the P-O structure becomes more disordered and the degree of polymerization of systems increase. The order of polymerization degree of distinct binary systems is BaO-AP(2)O(5) < K2O-AP(2)O(5) < Na2O-AP(2)O(5) < CaOAP(2)O(5). In addition, by linking the change law of the degree of polymerization of P2O5-based binary systems with macroscopic thermodynamic properties of dephosphorization, it is concluded that the dephosphorization capacity of varying binary systems is inversely proportional to their degree of polymerization. (C) 2021 Elsevier B.V. All rights reserved.