Non-Equilibrium Synthesis of Whitlockite Assisted by Localized H₂O Vapor Pressure

Whitlockite (Ca₁₈Mg₂(HPO₄)₂(PO₄)₁₂) has attracted considerable attention in the fields of bone grafting and bone regeneration due to the presence of magnesium ions and the HPO₄ ^2- group. However, conventional methods for synthesizing whitlockite require strict conditions and often result in excessive particle growth and compositional inhomogeneity. Here, we report the ultrafast and precisely controlled synthesis of whitlockite using a photothermal shock process induced by intense pulsed light (IPL). The formation of the whitlockite phase indicates that the precursor particles underwent a transient liquid phase and ion diffusion during IPL irradiation, facilitating the emergence of the new phase. Furthermore, we demonstrate that the H₂O-rich, high-pressure environment generated at the interface of carbon microheaters and the hydrated precursor plays a key role in whitlockite formation. This simple and rapid IPL-assisted approach provides an effective strategy for calcium phosphate crystallization and bioceramic fabrication, opening new avenues for controlled synthesis of complex phosphate phases.