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Page 32 of 57 Zheng et al. Soft Sci. 2026, 6, 32

negative charges on the MXene sheet surfaces, accelerating the creation of gel fibers while enhancing
strength and conductivity. While complete fiber creation was impossible without ionic crosslinking, Li et al.
showed that fibers spun from Mg -containing solutions attained tensile strengths up to 118 MPa and
2+
electrical conductivities of 7,200 S·cm -1[145] . Another crucial stage in post-processing for fiber structure
optimization is axial mechanical stretching. Internal cavities are eliminated and packing density and
orientation are increased as a result of the tensile force pushing nanoplates farther along the fiber axis.
Young’s modulus and electrical conductivity, for instance, are around 1.5 times higher in tensile-oriented
MXene fibers than in non-stretched fibers .
[26]

Through additional process condition optimization and creative structural design, researchers have
diversified MXene fiber architectures and specifically improved their attributes based on the previously
mentioned understanding of the spinning mechanism. Early research concentrated on increasing
spinnability by combining MXene with hydrophilic nanomaterials (such as GO, CNTs) or polymers [such as
regenerated cellulose (RC), PU] [Figure 10G]. Nevertheless, conductivity improvement was constrained by
the use of insulating or low-conductivity matrices [142] . Zhang et al. developed continuous wet spinning
utilizing pure MXene liquid crystal dispersions, advancing the technology into high-purity,
high-performance spinning, as their understanding of MXene’s nematic liquid crystal behavior deepened .
[33]
Building on this basis, customized production of multifunctional fibers is made possible by carefully
regulated spinning conditions. For example, Li et al. created MXene aerogel fibers with porosities greater
than 96.5% using Ca -induced fast gelation in conjunction with supercritical CO drying (N 2
2+
2
adsorption-desorption isotherm shown in Figure 11H) . They are appropriate for applications like flexible
[28]
sensing because they maintain the conducting network while displaying exceptional flexural elasticity and
high specific surface area (fiber cross-section and surface morphology shown in Figure 11I). As seen in the
cross-sectional SEM image in Figure 11J, Liu et al. created core-shell structured fibers with MXene as the
conductive core and ANFs as the protective shell in order to address MXene’s vulnerability to oxidation and
degradation . In addition to acting as a physical barrier, the ANF shell’s strong interfacial contacts with the
[114]
MXene core improve the fiber’s mechanical strength and environmental stability [Figure 11K and L].

A unique set of key parameters that are essentially different from those of graphene are involved in the wet
spinning of MXene fibers. There are two effects of sheet size: larger MXene sheets (e.g., lateral dimensions of
3.1 μm) encourage the formation of nematic liquid crystals at lower concentrations and result in higher
conductivity (7,713 S·cm ); smaller sheets (310 nm) allow for finer diameter control but show more edge
-1
defects and less orientation [33,128] . Continuous manufacturing of MXene/PU composite fibers longer than 100
meters has been accomplished, despite the fact that the spinning speed for pure MXene fibers is still
underquantified . Weaving experiments on an industrial scale show speeds similar to graphene systems. It
[143]
has been shown that stretch ratio and strain during stretching greatly improve performance: post-spinning
stretching results in a 1.5-fold improvement in Young’s modulus and conductivity, which is explained by
optimized interlayer orientation and decreased porosity . The solidification bath’s chemical characteristics
[26]
are crucial for MXene: a chitosan bath inhibits ion exchange, resulting in dense stacking and raising
conductivity to 7,748 S·cm , whereas acetic acid causes quick solidification but creates a porosity network
-1
(4,048 S·cm ) . Interlayer bridging is further improved by multivalent cation crosslinking (Mg , Ca , and
-1 [33]
2+
2+
NH ), which raises conductivity to 7,200 S·cm and tensile strength to 118 MPa [145] . Post-treatment
+
-1
4
parameters are very different from those for graphene: because of the substantial oxidation concerns,
high-temperature annealing is rarely used. Rather, the preferred methods are room-temperature drying,
supercritical CO drying (appropriate for aerogel fibers with porosities > 96.5% ), or protective
[28]
2
encapsulation (such as ANF encapsulation ). In contrast to graphene, environmental control - such as
[58]
oxygen-free environments - is a crucial extra factor in preventing oxidative deterioration when spinning. The
main obstacles in the production of modern MXene fiber are the interdependent interactions between these