Graphene Nanoribbons as an Advanced Precursor for Making Carbon Fiber

Abstract

Graphene oxide nanoribbons (GONRs) and chemically reduced graphene nanoribbons (crGNRs) were dispersed at high concentrations in chlorosulfonic acid to form anisotropic liquid crystal phases. The liquid crystal solutions were spun directly into hundreds of meters of continuous macroscopic fibers. The relationship of fiber morphology to coagulation bath conditions was studied. The effects of colloid concentration, annealing temperature, spinning air gap, and pretension during annealing on the fibers' performance were also investigated. Heat treatment of the as-spun GONR fibers at 1500 °C produced thermally reduced graphene nanoribbon (trGNR) fibers with a tensile strength of 378 MPa, Young's modulus of 36.2 GPa, and electrical conductivity of 285 S/cm, which is considerably higher than that in other reported graphene-derived fibers. This better trGNR fiber performance was due to the air gap spinning and annealing with pretension that produced higher molecular alignment within the fibers, as determined by X-ray diffraction and scanning electron microscopy. The specific modulus of trGNR fibers is higher than that of the commercial general purpose carbon fibers and commonly used metals such as Al, Cu, and steel. The properties of trGNR fibers can be further improved by optimizing the spinning conditions with higher draw ratio, annealing conditions with higher pretensions, and using longer flake GONRs. This technique is a new high-carbon-yield approach to make the next generation carbon fibers based on solution-based liquid crystal phase spinning.

Hybridizing wood cellulose and graphene oxide toward high-performance fibers

“…11 However, our infiltrated GO-NFC hybrid microfibers possess a high toughness of 4.9 MJ m − 3 (note that the fiber in reference 11 possesses a UTS of 214 MPa and a strain of 0.6%, which results in a lower toughness). The tensile strength of the infiltrated GO-NFC hybrid microfibers in this work is higher than that of wet-spun NFC microfibers (275 MPa, 28 402 MPa 34 ), LC GO microfibers (~102 MPa), 7 stretched Ca 2+ infiltrated GO microfibers (364 MPa), 13 hydrothermally reduced GO microfibers (180 MPa, after annealing at 800°C: 420 MPa), 35 microfibers prepared from GO nanoribbons (39.3 MPa, after 1050°C treatment: 383 MPa), 8 GO microfibers formed using large GO sheets (214 MPa) 11 and is even compatible to that of chemically cross-linked GO fibers (440 ± 60 MPa). 16 A comparable tensile strength to our infiltrated hybrid microfiber is also exhibited by the GO microfibers prepared from very large GO sheets coagulated from chitosan (442 MPa); the average diameter of the GO sheet is 37 μm.…”

“…6 Transforming 2D GO nanosheets into strong and highly ordered microfibers is a promising feat. [7][8][9][10][11][12] Efforts have been made to improve the mechanical properties of GO-based microfibers by chemical cross-linking and polymer coatings as well as through giant GO nanosheets. [13][14][15][16] GO microfibers exhibiting a tensile strength of 442 MPa and an elastic modulus of 47 GPa have been reported.…”

Scalable One‐Step Wet‐Spinning of Graphene Fibers and Yarns from Liquid Crystalline Dispersions of Graphene Oxide: Towards Multifunctional Textiles

“…The best as-spun GO fiber strength (~442 MPa) is higher than previously reported GO and rGO -based materials such as GO papers (~120 MPa), [36] RGOF/PVA fibers (~120 MPa), [37] LC GO fibers (~102 MPa), [14] stretched "ultrastrong" GO fibers (364 MPa), [17] fibers produced from graphene nanoribbons (378 MPa), [38] hydrothermally converted rGO fibers (~180 MPa) and thermally reduced rGO fibers (420 MPa). [39] In terms of modulus, the GO fiber (22.6 GPa) is inferior to the highest modulus of GO paper (42 GPa) [36] and fibers produced from graphene nanoribbons (36.2 GPa), [38] but the difference in breaking strain is substantial (3.2 % for GO fiber vs. ~0.4 % for GO paper and 1.1% for fibers produced from graphene nanoribbons) resulting in toughness (4.8 J g -1 ) considerably higher than both.…”

“…[39] In terms of modulus, the GO fiber (22.6 GPa) is inferior to the highest modulus of GO paper (42 GPa) [36] and fibers produced from graphene nanoribbons (36.2 GPa), [38] but the difference in breaking strain is substantial (3.2 % for GO fiber vs. ~0.4 % for GO paper and 1.1% for fibers produced from graphene nanoribbons) resulting in toughness (4.8 J g -1 ) considerably higher than both. [36,38] The strength of as-spun GO fiber is also much higher than single yarns of pure multi-walled CNTs (~250 MPa). [40] It should be noted that the GO used in this study is much larger compared to "giant GO" [17] (37µm in this study vs 18µm), which is the basis of the enhanced improvement in mechanical properties attained in the current study.…”

“…It should be noted that the overestimated area was used to determine the thermal conductivity of the samples resulting in an underestimated thermal conductivity values. [38] rGO fiber (glass pipeline moulding, annealed at 230 o C) -180 -10 3 - [39] rGO fiber (glass pipeline moulding, annealed at 800 o C) -420 --- [39] rGO fiber (reduced by hydroiodic acid) 5.4 130 -2.5×10 4 - [14] GO fibers coagulated by CaCl2 (stretched) 6.3 364 --- [17] rGO fibers coagulated by CaCl2 (reduced by hydroiodic acid and stretched) 11.2 501 -4.1 × 10 4 - [17] …”