Room-temperature growth of fluorapatite/CaCO3 heterogeneous structured composites inspired by human tooth

RSC Adv. 2022 Apr 8;12(18):11084-11089. doi: 10.1039/d2ra00374k. eCollection 2022 Apr 7.

Abstract

Organisms can synthesize heterogeneous structures with excellent mechanical properties through mineralization, the most typical of which are teeth. The tooth is an extraordinarily resilient bi-layered material that is composed of external enamel perpendicular to the tooth surface and internal dentin parallel to the tooth surface. The synthesis of enamel-like heterostructures with good mechanical properties remains an elusive challenge. In this study, we applied a biomimetic mineralization method to grow fluorapatite/CaCO3 (FAP/CaCO3) heterogeneous structured thin films that mimic their biogenic counterparts found in teeth through a three-step pathway: coating a polymer substrate, growing a layered calcite film, and mineralization of a fluorapatite columnar array on the calcite layer. The synthetic heterostructure composites combine well and exhibit good mechanical properties comparable to their biogenic counterparts. The FAP/CaCO3 heterogeneous structured composite exhibits excellent mechanical properties, with a hardness and Young's modulus of 1.99 ± 0.02 GPa and 47.5 ± 0.6 GPa, respectively. This study provides a reasonable new idea for unique heterogeneous structured materials designed at room temperature.