INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany; Experimental Physics, Saarland University, Campus D2 2, 66123 Saarbrücken, Germany.
INM-Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany.
Acta Biomater. 2014 Sep;10(9):3978-85. doi: 10.1016/j.actbio.2014.05.014. Epub 2014 May 23.
We investigated the friction and wear behavior as well as the mechanical properties of the periostracum of Mytilus sp. Tribological properties were determined with a reciprocal sliding microtribometer, while mechanical characterization was performed using a nanoindenter. Measurements were performed in dry and wet conditions. On the dry periostracum we found a low friction coefficient of 0.078±0.007 on the young parts and a higher one of 0.63±0.02 on the old parts of the shell. Under wet, saline, conditions we only observed one average coefficient of friction of 0.37±0.01. Microscopic ex situ analysis indicated that dry periostracum wore rather rapidly by plowing and fatigue, while it exhibited a high wear resistance when immersed in salt water. The Young's modulus and hardness of the periostracum were also investigated in both dry and wet conditions. Under dry conditions the Young's modulus of the periostracum was 8±3GPa, while under wet conditions it was 0.21±0.05GPa. The hardness of dry periostracum samples was 353±127MPa, whereas the hardness of wet samples was 5±2MPa. It was found that, in the wet state, viscous behavior plays a significant role in the mechanical response of the periostracum. Our results strongly indicate that the periostracum can provide an important contribution to the overall wear resistance of Mytilus sp. shell.
我们研究了贻贝壳珍珠层的摩擦磨损性能和力学性能。采用往复式微摩擦仪测定摩擦学性能，采用纳米压痕仪进行力学特性表征。在干、湿两种条件下进行了测量。在干燥的珍珠层表面，我们发现年轻贝壳部分的摩擦系数较低，为 0.078±0.007，而年老贝壳部分的摩擦系数较高，为 0.63±0.02。在湿润的盐水中，我们只观察到一个平均摩擦系数，为 0.37±0.01。微观原位分析表明，干燥的珍珠层通过犁耕和疲劳迅速磨损，而在盐水中则表现出较高的耐磨性。我们还研究了珍珠层在干、湿两种条件下的杨氏模量和硬度。在干燥条件下，珍珠层的杨氏模量为 8±3GPa，而在湿润条件下，杨氏模量为 0.21±0.05GPa。干燥珍珠层样品的硬度为 353±127MPa，而湿润样品的硬度为 5±2MPa。研究发现，在湿润状态下，粘性行为在珍珠层的力学响应中起着重要作用。我们的研究结果强烈表明，珍珠层可以为贻贝壳的整体耐磨性提供重要贡献。
