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Zheng et al. Soft Sci. 2026, 6, 32 Page 33 of 57

factors, especially the trade-offs between flake size, spinnability, and ultimate conductivity.

Other fabrication methods
While wet spinning shows great promise for producing high-performance continuous MXene fibers, other
techniques including coating, electrospinning, and dual-winding provide a variety of efficient supplementary
methods to satisfy the needs of different smart textile applications. These techniques take advantage of their
special advantages in structural diversity, material composite shapes, and process simplicity.

Method of coating
Scalable integration is made possible by the simple, inexpensive coating process. Its fundamental idea is to
quickly impart conductivity and certain functions by directly loading MXene dispersions onto pre-existing
fiber, yarn, or fabric substrates via dip-coating, drop-casting, or spraying processes. Figure 12A depicts a
schematic of the impregnation coating procedure. The creation of a strong interface binding between MXene
nanosheets and the substrate material and the development of a stable MXene dispersion are essential for the
effective application of this technique.

MXene has a negative charge in aqueous solutions due to the abundance of oxygen-containing functional
groups on its surface, such as -O and -OH. Tight adherence is thus made possible by MXene’s easy
formation of high electrostatic attraction and hydrogen bonding interactions with positively charged
substrates or those rich in polar functional groups (e.g., -OH, -COOH, -NH ). For example, MXene creates a
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three-dimensional electrical network by penetrating into the interstitial spaces within yarns [Figure 12B] and
uniformly coating the surface of individual fibers on both synthetic and natural fibers, such as nylon and
cotton [121] . Additionally, as seen in Figure 12C, X-ray photoelectron spectroscopy (XPS) investigation
suggests that -OH groups on the MXene surface may establish Ti-N covalent connections with amide groups
in nylon fibers, greatly increasing interfacial bonding strength and durability . On hydrophobic substrates
[136]
with low surface energy and few active sites, like polyester or silver-plated nylon, MXene, however, shows
poor adherence. Therefore, in order to improve interface compatibility with MXene, surface modification is
usually necessary. (1) Polymeric binders like PEDOT:PSS, which function as “bridges” to simultaneously
adhere MXene and the substrate, improve coating uniformity and bond strength; (2) Chemical coupling,
such as modification with silane coupling agents to graft active groups onto the substrate surface, enabling
electrostatic bonding with negatively charged MXene; and (3) Physical activation, such as oxygen plasma
treatment, which introduces oxygen-containing polar groups onto the substrate surface to improve
hydrophilicity.

Process compatibility and functional design flexibility are two clear benefits of the coating approach. Simple
cyclic coating cycles can provide precise control over MXene loading. For example, Bi et al. created a
high-speed continuous dip-coating method that orients MXene sheets on nylon fiber surfaces using shear
forces [146] . This technique shows the coating method’s potential for high-performance fiber mass
manufacturing by enabling wide-range MXene loading control with a single coating pass and obtaining
linear resistivity as low as ~10 Ω·cm . To combine several uses, more intricate multilayer composite coating
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patterns have been created. In order to create multifunctional hybrid aerogel fibers with effective
electromagnetic shielding, compressible resilience, and adjustable shielding mechanisms, Jia et al.
progressively constructed PEDOT:PSS and MXene “dual coatings” on an ANF scaffold [150] . Moreover,
multifunctional integration like photothermal response and superhydrophobicity is made possible by the
sequential deposition of adhesive, conductive, and functional layers on fibers with irregular cross-sections,
indicating the coating method’s great potential for building application-specific smart fiber systems .
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