Can AFM be used to measure absolute values of Young's modulus of nanocomposite materials down to the nanoscale?
Can AFM be used to measure absolute values of Young's modulus of nanocomposite materials down to the nanoscale?
复制标题
AFM 能否用于测量纳米复合材料杨氏模量的绝对值直至纳米尺度？
DOI：
10.1039/d0nr02314k
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发表时间：
2020-06-21
期刊：
影响因子：
6.7
通讯作者：
Peng, Ping'an
中科院分区：
文献类型：
--
作者：
Liu, Yuke;Sokolov, Igor;Peng, Ping'an
目前，一种可能能够测量纳米级杨氏模量值的技术是在压痕模式下工作的原子力显微镜（AFM）。然而，如果AFM压痕数据可以转化为模量的绝对值的问题还没有得到很好的研究，特别是对于最有趣的情况下，刚性纳米复合材料。在这里，我们调查这个问题。使用了一种特殊的纳米复合材料样品，页岩，它在多微米尺度上相对均匀。在这项研究中使用了两种AFM模式，力-体积和PeakForce QNM。纳米压痕技术被用作测量页岩样品的有效杨氏模量的控制基准。压痕速率被仔细控制。为了确保用于分析原子力显微镜数据的力学模型的自一致性，对该模型进行了修改，以考虑表面粗糙度的存在。我们发现AFM和纳米压头基准方法计算的有效杨氏模量的平均值之间的良好协议。同时，样品的最软和最硬区域仅用AFM看到。
At present, a technique potentially capable of measuring values of Young's modulus at the nanoscale is atomic force microscopy (AFM) working in the indentation mode. However, the question if AFM indentation data can be translated into absolute values of the modulus is not well-studied as yet, in particular, for the most interesting case of stiff nanocomposite materials. Here we investigate this question. A special sample of nanocomposite material, shale rock, was used, which is relatively homogeneous at the multi-micron scale. Two AFM modes, force-volume and PeakForce QNM were used in this study. The nanoindentation technique was used as a control benchmark for the measurement of effective Young's modulus of the shale sample. The indentation rate was carefully controlled. To ensure the self-consistency of the mechanical model used to analyze AFM data, the model was modified to take into account the presence of the surface roughness. We found excellent agreement between the average values of effective Young's modulus calculated within AFM and the nanoindenter benchmark method. At the same time, the softest and hardest areas of the sample were seen only with AFM.