Ingenious crosslinking/condensation mechanism of amino silane: Simultaneous realization of the stable synthesis of amorphous precursors ACP and ACC

Amorphous calcium phosphate (ACP) and amorphous calcium carbonate (ACC) are the core materials in the biogenic construction of protective shells and functional architectures. Through non-classical crystallization pathways, organisms transform these amorphous phases into inorganic materials with excellent mechanical, optical or adhesive properties, such as bones, nacre, and oyster reefs, which are formed under mild environments but exhibit remarkable resilience in extreme conditions. Consequently, biomimetic mineralization strategies leveraging ACP and ACC hold significant promise for novel material synthesis. At present, ACP and ACC cannot be synthesized under the same mechanism, and the existing methods usually weaken the stability and biomaterial properties of products. In this study, an ethanol-based system was employed to achieve the stable synthesis of ACP and ACC with the assistance of biocompatible γ-aminopropyltriethoxysilane (APTES). The mechanism of APTES with Ca 2+ , PO 4 3- , and CO 3 2- during the synthesis process was elucidated. The resulting ACP and ACC exist as stable nanoclusters that can be stored long-term at room temperature. Upon induced crystallization, they crystallize into hydroxyapatite, calcite, vaterite, and magnesium calcite. The excellent biomaterial properties make them highly suitable as precursors for biomimetic mineralization. • New synthetic route for amorphous calcium phosphate (ACP) and amorphous calcium carbonate (ACC). • The non-toxic, odorless and excellent biocompatibility of amino silane effectively protects the biological properties of amorphous precursors. • The preparation and storage of ACP and ACC were achieved at room temperature, and the products were stable and could be stored for extended periods under ambient conditions. • First-principles calculations were employed to elucidate the interaction mechanism between amino silane and the target ions. • The products ACP and ACC nanoclusters show excellent biomimetic mineralization potential.