Competition and Neutralization: Thermally Induced Crystallization and Phase Evolution of Amorphous Calcium Phosphate with Cosubstitution of Larger and Smaller Divalent Cations

Lu Wang; Junxing Yang; Jianqiang Bi; Kangning Sun; Aimin Li; Junjie Mao

doi:10.1021/acsomega.2c07117

Competition and Neutralization: Thermally Induced Crystallization and Phase Evolution of Amorphous Calcium Phosphate with Cosubstitution of Larger and Smaller Divalent Cations

ACS Omega. 2023 Feb 15;8(8):7602-7606. doi: 10.1021/acsomega.2c07117. eCollection 2023 Feb 28.

Authors

Lu Wang^{1

2}, Junxing Yang^{1

2}, Jianqiang Bi^{1

2}, Kangning Sun^{1

2}, Aimin Li^{1

2}, Junjie Mao^{1

2}

Affiliations

¹ Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, Shandong University, Jinan 250061, People's Republic of China.
² School of Materials Science & Engineering, Shandong University, Jinan 250061, People's Republic of China.

Abstract

The presented study evaluated the effect of cosubstitution of larger and smaller divalent cations on the thermally induced crystallization of amorphous calcium phosphate (ACP). The predesigned combinations of larger (Sr²⁺ and Ba²⁺) and smaller (Mg²⁺, Cu²⁺, and Co²⁺) divalent cations were carried out and their effects on the thermodynamic equilibrium between α/β-tricalcium phosphate (TCP) were outlined. The coexistence of larger and smaller divalent cations shielded the formation of α-TCP and shifted the thermodynamic equilibrium toward the β-TCP, which implied that the smaller cations dominated the crystalline phase. However, the retarded crystallization induced by the larger cations still remained and allowed ACP to maintain its amorphous nature partly or completely until a higher temperature.