Scalable Mussel-Inspired CNT Hybrid Coatings for Durable and Conductive Electrospun Nanofiber Yarns

Wearable electronics and smart textiles require fiber-based materials that combine mechanical robustness, electrical conductivity, responsive behavior, and durability. Electrospun nanofibers, however, often suffer from intrinsic fragility and limited structural stability. In this study, electrospun poly(vinylidene fluoride) (PVDF) webs were converted into continuous multifunctional yarns using a slit-and-twist process, followed by coating with mussel adhesive protein (MAP)-dispersed double-walled carbon nanotubes (DWNTs), Fe³⁺-induced crosslinking, and vacuum ultraviolet (VUV) irradiation. The tensile toughness increased from 43.40 ± 1.30 MJ m⁻³ for pristine PVDF yarn to 69.92 ± 4.78 MJ m⁻³ for the Fe³⁺-crosslinked MAP–DWNT yarn, corresponding to a 61.1% enhancement. After multiple coating cycles, the fully processed yarn exhibited an apparent conductivity of 199.9 S m⁻¹, calculated from two-probe resistance using the nominal external yarn diameter. The yarns also showed strain-dependent electrical behavior and preliminary chemiresistive responses to NO 2 , NH 3 , and H 2 . Under the tested conditions, MAP-containing yarns exhibited greater than 99% bacterial inhibition against Staphylococcus aureus . These results demonstrate an integrated MAP-assisted DWNT coating platform for improving the mechanical and functional properties of continuous electrospun nanofiber yarns.