Swansea University Medical School, Swansea SA2 8PP, UK.
Nanoscale. 2018 Jan 3;10(2):520-525. doi: 10.1039/c7nr07070e.
Localized variations at the nanoscale in soil aggregates and in the spatial organisation of soil organic matter (SOM) are critical to understanding the factors involved in soil composition and turnover. However soil nanoscience has been hampered by the lack of suitable methods to determine soil biophysical properties at nanometre spatial resolution with minimal sample preparation. Here we introduce for the first time an Atomic Force Microscopy (AFM)-based Quantitative Nano-Mechanical mapping (QNM) approach that allows the characterisation of the role of SOM in controlling surface nano-mechanical properties of soil aggregates. SOM coverage resulted in an increased roughness and surface variability of soil, as well as in decreased stiffness and adhesive properties. The latter also correlates with nano- to macro-wettability features as determined by contact angle measurements and Water Drop Penetration Time (WDPT) testing. AFM thus represents an ideal quantitative tool to complement existing techniques within the emerging field of soil nanoscience.
土壤团聚体和土壤有机质（SOM）空间组织的纳米尺度局部变化对于理解土壤组成和转化所涉及的因素至关重要。然而，由于缺乏合适的方法来以最小的样品制备在纳米空间分辨率下确定土壤生物物理特性，土壤纳米科学受到了阻碍。在这里，我们首次介绍了一种基于原子力显微镜（AFM）的定量纳米力学映射（QNM）方法，该方法允许表征 SOM 在控制土壤团聚体表面纳米力学性质中的作用。SOM 覆盖导致土壤粗糙度和表面可变性增加，以及硬度和粘附性降低。后者还与通过接触角测量和水滴渗透时间（WDPT）测试确定的纳米到宏观润湿性特征相关。因此，AFM 是一种理想的定量工具，可以补充新兴土壤纳米科学领域中现有技术。
