Department of Mechanical Engineering, University of Texas Rio Grande Valley , 1201 West University Drive, Edinburg, Texas 78539, United States.
Department of Physics, University of Texas Rio Grande Valley , 1201 West University Drive, Edinburg, Texas 78539, United States.
ACS Appl Mater Interfaces. 2017 Aug 2;9(30):25474-25480. doi: 10.1021/acsami.7b07509. Epub 2017 Jul 20.
We report a scalable method to obtain a new material where large graphene sheets form webs linking carbon fibers. Film-fiber hybrid nonwoven mats are formed during fiber processing and converted to carbon structures after a simple thermal treatment. This contrasts with multistep methods that attempt to mix previously prepared graphene and fibers, or require complicated and costly processes for deposition of graphene over carbon fibers. The developed graphene-fiber hybrid structures have seamless connections between graphene and fibers, and in fact the graphene "veils" extend directly from one fiber into another forming a continuous surface. The graphene-fiber hybrid structures are produced in situ from aqueous poly(vinyl alcohol) solutions. The solutions were subjected to centrifugal spinning to produce fine nanofiber mats. The addition of salt to the polymer solution stimulated a capillarity effect that promoted the formation of thin veils, which become graphene sheets upon dehydration by sulfuric acid vapor followed by carbonization (at relatively low temperatures, below 800 °C). These veils extend over several micrometers within the pores of the fiber network, and consist of crystalline graphene layers that cross-link the fibers to form a highly interconnected hybrid network. The surface area and pore diameter of the hybrid structures were measured to be 521 mg and 10 nm, respectively. The resulting structure shows high electrical conductivity, 550 S/m, and promising shielding of electromagnetic interference, making it an attractive system for a broad range of electronic applications.
我们报告了一种可扩展的方法，可获得一种新材料，其中大的石墨烯片形成连接碳纤维的网络。在纤维加工过程中形成纤维-薄膜混合无纺毡，经过简单的热处理即可转化为碳结构。这与试图混合先前制备的石墨烯和纤维的多步方法形成对比，或者需要对碳纤维进行石墨烯复杂且昂贵的沉积过程。所开发的石墨烯-纤维混合结构在石墨烯和纤维之间具有无缝连接，实际上，石墨烯“面纱”直接从一根纤维延伸到另一根纤维，形成连续的表面。石墨烯-纤维混合结构是从水性聚乙烯醇溶液原位产生的。将溶液进行离心纺丝以生产出细的纳米纤维毡。向聚合物溶液中添加盐会刺激毛细作用，从而促进形成薄的面纱，这些面纱在硫酸蒸气脱水后并碳化（在相对较低的温度下，低于 800°C）变成石墨烯片。这些面纱在纤维网络的孔内延伸数微米，由交联纤维形成高度互联的混合网络的结晶石墨烯层组成。测量混合结构的比表面积和孔径分别为 521 mg 和 10nm。所得结构表现出高导电性，为 550 S/m，并具有电磁干扰屏蔽的潜力，使其成为广泛电子应用的有吸引力的系统。
