Fig. 4. Preparation and properties of lignin-derived CNT fibers.

Preparation diagrams of a TCFs and b RCFs. SEM images of c TCFs and d RCFs. Polarized Raman spectra of e TCFs and f RCFs. g Tensile stress-strain curves of the TCFs and RCFs. h Comparison of tensile strength and fracture work for the TCFs and RCFs. Error bars represent s.d. (n = 5). i Comparison of the thermal conductivity and density between our CNT films and other materials^48,60–67. j Comparison of the tensile strength and electrical conductivity of our CNT fibers with commercial carbon fibers⁶⁸, wet-spun CNT fibers^18,69–71, CNT fibers from FCCVD^{25,56,72–74}, CNT fibers from array spinning^75–79, common metal materials⁶⁷, and biomass-derived carbon fibers^80–86.