Ramírez-Herrera Claudia Angélica, Gonzalez Homero, Torre Felipe de la, Benitez Laura, Cabañas-Moreno José Gerardo, Lozano Karen
Programa de Doctorado en Nanociencias y Nanotecnología, CINVESTAV, Av. Instituto Politécnico Nacional 2508, Cd. de México 07360, Mexico.
Mechanical Engineering Department, The University of Texas Rio Grande Valley, 1201 West University Drive, Edinburg TX 78539, USA.
Nanomaterials (Basel). 2019 Feb 10;9(2):238. doi: 10.3390/nano9020238.
The demand for multifunctional requirements in aerospace, military, automobile, sports, and energy applications has encouraged the investigation of new composite materials. This study focuses on the development of multiwall carbon nanotube (MWCNT) filled polypropylene composites and carbon nanofiber composite mats. The developed systems were then used to prepare interlayered composites that exhibited improved electrical conductivity and electromagnetic interference (EMI) shielding efficiency. MWCNT-carbon nanofiber composite mats were developed by centrifugally spinning mixtures of MWCNT suspended in aqueous poly(vinyl alcohol) solutions. The developed nanofibers were then dehydrated under sulfuric acid vapors and then heat treated. Interlayered samples were fabricated using a nanoreinforced polypropylene composite as a matrix and then filled with carbon fiber composite mats. The in-plane and through-plane electrical conductivity of an eight-layered flexible carbon composite (0.65 mm thick) were shown to be 6.1 and 3.0 × 10 S·cm, respectively. The EMI shielding effectiveness at 900 MHz increased from 17 dB for the one-layered composite to 52 dB for the eight-layered composite. It was found that the reflection of the electromagnetic waves was the dominating mechanism for EMI shielding in the developed materials. This study opens up new opportunities for the fabrication of novel lightweight materials that are to be used in communication systems.
航空航天、军事、汽车、体育和能源应用中对多功能需求的增加，促使人们对新型复合材料展开研究。本研究聚焦于多壁碳纳米管（MWCNT）填充聚丙烯复合材料及碳纳米纤维复合垫的开发。随后，利用所开发的体系制备出具有改善的导电性和电磁干扰（EMI）屏蔽效率的层间复合材料。MWCNT - 碳纳米纤维复合垫是通过离心纺丝悬浮于聚乙烯醇水溶液中的MWCNT混合物而制备的。然后将所制备的纳米纤维在硫酸蒸汽中脱水，接着进行热处理。层间样品是以纳米增强聚丙烯复合材料为基体进行制备，然后填充碳纤维复合垫。一种八层柔性碳复合材料（厚度0.65毫米）的面内和面外电导率分别为6.1和3.0×10 S·cm。在900兆赫兹时，EMI屏蔽效能从单层复合材料的17分贝提高到八层复合材料的52分贝。研究发现，电磁波反射是所开发材料中EMI屏蔽的主导机制。本研究为制造用于通信系统的新型轻质材料开辟了新机遇。
