University of Illinois at Urbana-Champaign, IL, Urbana, 61801, Ilinois, USA.
Nanoscale. 2017 Nov 9;9(43):16689-16699. doi: 10.1039/c7nr05347a.
The presence of nanogranular microstructures is a widely reported feature of biominerals that form by classical and non-classical mineralization pathways. Inspired by nature, we have synthesized amorphous calcium carbonate nanoparticles with nanogranular microstructures, whose grain size is tuned by varying the polymer concentration. The response to indentation of single calcium carbonate nanoparticles proceeds via an intermittent stick-slip that reflects the characteristics of the nanogranular microstructure. A two-fold mechanism is thus proposed to enhance the toughness of the nanoparticles, namely nanogranular rearrangement and intergranular bridging by an organic phase and/or hydration. This work not only provides a synthesis route to design biologically inspired mineral nanoparticles with nanogranular structure, but also helps in understanding toughening mechanisms of biominerals arising from their nanoscale heterogeneity.
纳米颗粒微观结构的存在是通过经典和非经典矿化途径形成的生物矿化的一个广泛报道的特征。受自然启发，我们用具有纳米颗粒微观结构的无定形碳酸钙纳米粒子，其粒径通过改变聚合物浓度进行调节。单个碳酸钙纳米粒子的压痕响应通过间歇性的粘滑进行，这反映了纳米颗粒微观结构的特征。因此，提出了一种双重机制来增强纳米粒子的韧性，即纳米颗粒的纳米颗粒重排和通过有机相和/或水合作用的颗粒间桥接。这项工作不仅提供了一种设计具有纳米颗粒结构的仿生矿化纳米粒子的合成途径，而且有助于理解生物矿化的增韧机制，这源于其纳米尺度的非均质性。
