In Situ Production of Graphene–Fiber Hybrid Structures

Abstract

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.

Electrical Properties and Electromagnetic Interference Shielding Effectiveness of Interlayered Systems Composed by Carbon Nanotube Filled Carbon Nanofiber Mats and Polymer Composites

“…The above-mentioned systems are highly desired in important applications, for example, in the development of rigid wall shelters for defense-related applications and in novel cable systems (uses ranging from everyday applications to aerospace applications). This study effectively addresses the needs that are mentioned above by developing nonwoven carbon composite mats, taking advantage of the Forcespinning ® method that uses centrifugal force to spin fine fibers (nano-, submicron-, and single digit fibers) at industrial scales, (hundreds of meters per minute) [26,27]. The developed multiwall carbon nanotube (MWCNT) filled carbon nanofiber mats were stacked using a matrix that was composed of MWCNT reinforced polypropylene.…”

Editorial: Carbon- and Inorganic-Based Nanostructures for Energy Applications

“…Cesano et al reviewed the topic of metal-free conductors based on macrosized and nanoscale carbons (i.e., carbon fibers, carbon nanotubes, graphene) from the viewpoint of the electrical and thermal conductivity for electronic and electrical wiring applications. Specifically, CNTs and graphene can be assembled into macroscopic fibers, yarns and ropes to be used as conductors (Akia et al, 2017;Jang et al, 2020). From the perspective of replacing metals, which are present in nature with limited amounts, the role played by the chemistry in helping to exceed the electrical conductivity of metals by means of the molecular-level control and doping, is emphasized.…”

Uniaxial tensile investigation of a porous compound nonwoven fabric

“…For instance, Leary et al reported a pseudocapacitor electrode based on the CF nonwoven fabric, and the resulting electrode demonstrated excellent properties with a high specific capacitance of 80 F/g. In a separate work, Akia et al produced a 0.15‐mm‐thick conductive CF nonwoven fabric that exhibited an electromagnetic interference shielding effectiveness value of 30.2 dB. Nevertheless, most available CF nonwoven fabrics are unsatisfactory in tensile strength and mechanical flexibility due to the high rigidity of CFs .…”