Koh Kwang Liang, Ji Xianbai, Dasari Aravind, Lu Xuehong, Lau Soo Khim, Chen Zhong
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
Singapore Institute of Manufacturing Technology, 73 Nanyang Drive, Singapore 638075, Singapore.
Materials (Basel). 2017 Jul 10;10(7):776. doi: 10.3390/ma10070776.
This paper examines the effect of surface treatment and filler shape factor on the fracture toughness and elastic modulus of epoxy-based nanocomposite. Two forms of nanofillers, polydopamine-coated montmorillonite clay (D-clay) and polydopamine-coated carbon nanofibres (D-CNF) were investigated. It was found that Young's modulus increases with increasing D-clay and D-CNF loading. However, the fracture toughness decreases with increased D-clay loading but increases with increased D-CNF loading. Explanations have been provided with the aid of fractographic analysis using electron microscope observations of the crack-filler interactions. Fractographic analysis suggests that although polydopamine provides a strong adhesion between the fillers and the matrix, leading to enhanced elastic stiffness, the enhancement prohibits energy release via secondary cracking, resulting in a decrease in fracture toughness. In contrast, 1D fibre is effective in increasing the energy dissipation during fracture through crack deflection, fibre debonding, fibre break, and pull-out.
本文研究了表面处理和填料形状因子对环氧基纳米复合材料断裂韧性和弹性模量的影响。研究了两种形式的纳米填料，聚多巴胺包覆的蒙脱土（D-粘土）和聚多巴胺包覆的碳纳米纤维（D-CNF）。结果发现，杨氏模量随着D-粘土和D-CNF含量的增加而增加。然而，断裂韧性随着D-粘土含量的增加而降低，但随着D-CNF含量的增加而增加。借助于使用电子显微镜观察裂纹-填料相互作用的断口分析提供了解释。断口分析表明，尽管聚多巴胺在填料和基体之间提供了很强的附着力，导致弹性刚度增强，但这种增强阻止了通过二次开裂释放能量，导致断裂韧性降低。相比之下，一维纤维通过裂纹偏转、纤维脱粘、纤维断裂和拔出有效地增加了断裂过程中的能量耗散。
