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A facile continuous wet-spinning of graphene oxide fibers from aqueous solutions at high pH with the introduction of ammonia

Wu, Changcun, Wang, Xia, Zhuo, Qiqi, Sun, Jun, Qin, Chuanxiang, Wang, Jianjun, Dai, Lixing
Carbon 2018 v.138 pp. 292-299
acetone, ammonia, ammonium, aqueous solutions, chemical reduction, coagulants, coagulation, dispersibility, electrical conductivity, graphene, graphene oxide, methanol, modulus of elasticity, pH, salts, tensile strength
Continuous preparation of graphene oxide (GO) fibers as precursors of graphene fibers has been realized via wet-spinning of GO aqueous solution, but there are still some challenges in easiness and simplicity of preparation. Herein, a facile method was developed to prepare GO fibers through continuous process, which was well realized by wet-spinning the ammonia added GO (NGO) aqueous solution with pH 11 in a newly developed coagulation bath, a mixture of methanol and acetone (v/v = 1/2). The introduction of ammonia efficiently enhanced dispersibility of GO sheets in the aqueous solution with high pH through de-protonation of GO sheets, and at the same time largely improved coagulation effect through the combination of de-protonated GO sheets with ammonium ions to form salts in the coagulant. The obtained NGO fiber showed good mechanical properties, tensile strength of 141 MPa and Young's modulus of 3.7 GPa at 5.6% elongation. The reduced NGO (RNGO) fiber prepared by chemical reduction had better tensile strength of 217 MPa and Young's modulus of 5.5 GPa, as well as good electrical conductivity of 1611 S m−1.