Electroless Plating of Graphene Aerogel Fibers for Electrothermal and Electromagnetic Applications

Abstract

Graphene aerogel fibers (GAFs) with low density, high specific surface area, and high porosity can be used as the host material to incorporate another component and thus form multifunctional fibers, which have potential applications in wearable devices, thermoregulating apparatus, sensors, and so forth. However, the intrinsically low electric conductivity of GAFs hampers them in the fields of electrothermal heating and electromagnetic interference (EMI) shielding. Herein, we report a new aerogel fiber composed by graphene sheets and nickel nanoparticles with low density (55−192 mg/cm 3 ), high electric conductivity (0.8 × 10 3 to 4.5 × 10 4 S/m), and high specific surface area (49− 105 m 2 /g). The graphene/Ni aerogel fibers (GNAFs) were synthesized initially from reduced graphene oxide hydrogel fibers followed by an electroless plating process. Further investigations have demonstrated that the resulting GNAFs possess excellent electrothermal property, faster electrothermal response, high mechanical and electrical stability as the electric wire, and excellent EMI shielding performance as the composite filler. The saturated temperature of GNAFs can reach 174 °C with an applied voltage of only 5 V, and the heating rate surpasses those of commercial Kanthal and Nichrome wires about 2.1 times and 2.6 times, respectively. The EMI shielding effectiveness of GNAFs is higher than 30 dB at the long bandwidth of 12.5−20 GHz. Specifically, it can shield more than 99.99% of the incident wave at the bandwidth of 15−20 GHz.

Facile Preparation of Continuous and Porous Polyimide Aerogel Fibers for Multifunctional Applications

“…As seen in the cross-sectional SEM images of PAFs (Figure S3), the unique "porous core−dense sheath" structure is likely responsible for the high strength of PAFs, where the dense sheath contributes to the high tensile strength of PAFs. As is well known, the prepared PAFs in the present work show the highest tensile strength compared with the previously reported porous silk fibroin/chitosan aerogel fibers, 30 silk aerogel fibers, 41 graphene aerogel fibers, 31,42,43 cellulose aerogel fibers, 20,44 KNF aerogel fibers, 29 and porous polyimide fibers 45 as well as graphene/PU aerogel fibers. 46 Based on the excellent flexibility and mechanical behavior, the PAFs could be easily weaved into fabricates for a better practical application possibility.…”

Hygroscopic holey graphene aerogel fibers enable highly efficient moisture capture, heat allocation and microwave absorption

“…Aerogel fibers have been the focal points in a broad spectrum of applications, ranging from thermal insulation 1 – 4 , wearable textiles 3 , 5 , to stimuli-responsive electronics 6 , due to their high specific area, high porosity, low density, and low thermal conductivity. A variety of materials can be fabricated into aerogel fibers, such as polymers (e.g., Kevlar, polyimide) 3 , 7 , ceramics (e.g., silica, boron nitride) 1 , 4 , 8 , 9 , carbon-based materials (e.g., CNT, graphene, MXene) 6 , 10 – 12 , and hybrid materials (e.g., cellulose/cobalt ferrite, silk fibroin/graphene oxide, graphene/Ni) 5 , 13 , 14 . Different strategies are exploited for the construction of aerogel fibers starting from variant nanoscale building blocks, for instance, reaction spinning 4 , coaxial spinning 5 , wet spinning 6 , 10 , and sol-gel confined transition method 7 .…”

The Rising Aerogel Fibers: Status, Challenges, and Opportunities

“…A similar methodology is also applicable to TiO 2 aerogel fiber, which is formed by taking tetrabutyl titanate and ethanol as the spinning dope and acetic acid as the hydrolysis inhibitor in a coagulation bath. [22] For the composite aerogel fibers, a variety of hybrid materials has been developed, for example, calcium alginate/Fe 3 O 4 nanoparticles/Ag nanowires (CA/Fe 3 O 4 /Ag NWs), [28] Ni/graphene, [37] silk fibroin/graphene oxide, [38] polyamidoxime/aramid nanofiber (PAO/ANF), [46] and aramid nanofibers/carbon nanotube/polypyrrole (ANF/CNT/PPy). [51] These hybrid structures can be realized by either an in situ approach or a post-treatment such as coating the guest component.…”