State Key Laboratory of High Performance Ceramics & Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China. Structural Ceramics and Composites Engineering Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China. University of Chinese Academy of Sciences, Beijing 100039, People's Republic of China.
Nanotechnology. 2019 Jul 5;30(27):275602. doi: 10.1088/1361-6528/ab127f. Epub 2019 Mar 22.
This work reports a bioinspired anisotropic nanocomposite by polar solution assisted mechanical stretching method, consisting of polyvinyl alcohol (PVA) and silicon carbide nanowires (SiCNWs) with aligned morphology in one direction. Inspired by the structural mimicry of myofibers, in which the uniaxial mechanical property of materials can be improved evidently, highly-aligned SiCNWs and PVA chains that interact using intermolecular force can be obtained. Hysteresis is observed and reversible deformation occurs while tensile-relaxation cycles are applied to the 100% stretched SiCNWs/PVA nanocomposites. The nanocomposites exhibit excellent properties and the tensile strength of 100% stretched SiCNWs/PVA nanocomposites is 188.30 ± 4.2 MPa and elastic modulus is 6.95 GPa, which are increased by 421.90% and 581.37% compared with pure PVA. Finite element simulation of fracture mechanism shows good agreement with the experimental results. An improvement of thermal conductivity is also achieved in well-aligned SiCNWs/PVA. The work imitates the structure of mammal muscle and also has great potential for the macroscopic application of one-dimensional nanomaterials as super flexible heat dissipation materials.
本工作通过极性溶液辅助机械拉伸方法制备了一种各向异性的纳米复合材料，由沿一个方向排列的形态的聚乙烯醇（PVA）和碳化硅纳米线（SiCNWs）组成。受肌纤维结构模拟的启发，其中材料的单轴机械性能可以明显提高，可以获得高度取向的 SiCNWs 和通过分子间力相互作用的 PVA 链。在对 100%拉伸的 SiCNWs/PVA 纳米复合材料施加拉伸-松弛循环时，观察到滞后现象并发生可逆变形。纳米复合材料表现出优异的性能，100%拉伸的 SiCNWs/PVA 纳米复合材料的拉伸强度为 188.30 ± 4.2 MPa，弹性模量为 6.95 GPa，与纯 PVA 相比分别提高了 421.90%和 581.37%。断裂机制的有限元模拟与实验结果吻合较好。在 SiCNWs 良好排列的情况下，热导率也得到了提高。这项工作模拟了哺乳动物肌肉的结构，也为一维纳米材料作为超灵活散热材料的宏观应用提供了巨大的潜力。
