Refined platelet size: Unlocking enhanced mechanics in nacre-mimetic mineralized materials

Abstract

Nacre-mimetic mineralized (NMM) materials with outstanding mechanical properties have been considered as future structural materials. However, replicating nacre's characteristics into artificial ones in mild conditions has been challenging, particularly in controlling the platelet size, which is crucial for mechanical performance. Here, inspired by mollusk biomineralization, we achieve the unprecedented regulation of aragonite platelet sizes (ranging from 76 to 5800 μm²) at the micrometer scale by manipulating amorphous nano calcium carbonate content, thereby enhancing the mechanical properties of NMM materials. Experimental and simulation results demonstrate that merely decreasing the aragonite platelets' sizes can significantly increase the flexural strength and modulus by 2.8 and 9.9 times, respectively. Notably, the proposed strategy not only has the potential for large-scale production but also produces refined NMM material that closely resembles natural nacre in terms of microstructure and mechanical properties, showing ca. 26 % improvement in specific strength over previously reported NMM materials. Consequently, this work provides a feasible way for developing advanced biomimetic structural materials with specific functions, such as protective gear and artificial bone grafts.