Ohashi Takumi, Sato Tomoyuki, Nakajima Taichi, Junkong Preeyanuch, Ikeda Yuko
Graduate School of Science and Technology, Kyoto Institute of Technology Matsugasaki, Sakyo Kyoto 606-8585 Japan.
Center for Rubber Science and Technology, Kyoto Institute of Technology Matsugasaki, Sakyo Kyoto 606-8585 Japan.
RSC Adv. 2018 Sep 24;8(57):32930-32941. doi: 10.1039/c8ra06669h. eCollection 2018 Sep 18.
The importance of the two-dimensional (2D) visualization of validity for nanomechanical mapping in atomic force microscopy (AFM) for sulphur cross-linked rubber is emphasized for accurately interpreting the nanoscale physical properties on the surface of the soft material. The "-factor," evaluated to be the difference between the experimental and theoretical force-deformation curves, was considered to be the reliability index of the AFM analysis for all data points on the sample surface. A small -factor corresponds to high accuracy. The advantage of the -factor mapping method is demonstrated using nanomechanical mapping data of the inhomogeneous isoprene rubber network by the Johnson-Kendall-Roberts and the Derjaguin, Muller, and Toporov contact mechanics models. The 2D -factor mapping clearly and correctly supported the roles of sulphur cross-linking reagents to control the network morphology of vulcanizates. Additionally, the blanket effect, which is induced by the rubber layer on the hard part and influences experimental force-deformation curves, is firstly proposed in this study. Nanomechanical mapping with 2D reliability indexes is expected to contribute to an advance in AFM studies on soft matter such as rubber materials, leading to a more accurate understanding of the structural characteristics of the rubber networks. Thus, this validity confirmation method is necessary for developing rubber science and technology.
强调了在原子力显微镜（AFM）中对硫交联橡胶进行纳米力学映射时二维（2D）有效性可视化对于准确解释软材料表面纳米级物理性质的重要性。被评估为实验力-变形曲线与理论力-变形曲线之间差异的“-因子”，被视为样品表面所有数据点AFM分析的可靠性指标。较小的-因子对应于高精度。通过约翰逊-肯德尔-罗伯茨模型和德亚金、穆勒和托波罗夫接触力学模型，利用非均相异戊二烯橡胶网络的纳米力学映射数据证明了-因子映射方法的优势。二维-因子映射清晰且正确地支持了硫交联剂在控制硫化胶网络形态方面的作用。此外，本研究首次提出了由硬部件上的橡胶层引起并影响实验力-变形曲线的覆盖效应。具有二维可靠性指标的纳米力学映射有望推动对橡胶材料等软物质的AFM研究进展，从而更准确地理解橡胶网络的结构特征。因此，这种有效性确认方法对于橡胶科学技术的发展是必要的。
