Department of Mechanical and Industrial Engineering, University of Illinois at Chicago , 842 W. Taylor Street, Chicago, Illinois 60607-7022, United States.
Multifunctional Structural Composite Research Center, Institute of Advanced Composites Materials, Korea Institute of Science and Technology , Chudong-ro 92, Bondong-eup, Wanju-gun, Jeollabuk-do 55324, Republic of Korea.
ACS Appl Mater Interfaces. 2017 Aug 16;9(32):27223-27231. doi: 10.1021/acsami.7b06864. Epub 2017 Aug 2.
Here, we investigate crack propagation initiated from an initial notch in a self-healing material. The crack propagation in the core-shell nanofiber mats formed by coelectrospinning and the composites reinforced by them is in focus. All samples are observed from the crack initiation until complete failure. Due to the short-time experiments done on purpose, the resin and cure released from the cores of the core-shell nanofibers could not achieve a complete curing and stop crack growth, especially given the fact that no heating was used. The aim is to elucidate their effect on the rate of crack propagation. The crack propagation speed in polyacrylonitrile (PAN)-resin-cure nanofiber mats (with PAN being the polymer in the shell) was remarkably lower than that in the corresponding monolithic PAN nanofiber mat, down to 10%. The nanofiber mats were also encased in polydimethylsiloxane (PDMS) matrix to form composites. The crack shape and propagation in the composite samples were studied experimentally and analyzed theoretically, and the theoretical results revealed agreement with the experimental data.
在这里，我们研究了自修复材料中初始缺口引发的裂纹扩展。重点研究了共纺丝形成的核壳纳米纤维垫和增强它们的复合材料中的裂纹扩展。所有样品均从裂纹起始直至完全失效进行观察。由于专门进行了短时间实验，因此从核壳纳米纤维的核心释放的树脂和固化剂无法完全固化并阻止裂纹生长，尤其是在没有加热的情况下。目的是阐明它们对裂纹扩展速度的影响。在聚丙烯腈（PAN）-树脂-固化剂纳米纤维垫（其中 PAN 是壳中的聚合物）中的裂纹扩展速度明显低于相应的整体 PAN 纳米纤维垫，低至 10%。还将纳米纤维垫封装在聚二甲基硅氧烷（PDMS）基质中以形成复合材料。实验研究了复合材料样品中的裂纹形状和扩展，并进行了理论分析，理论结果与实验数据吻合。
