Transparent conductive fiber is an indispensable part of textile displays. The predominant strategy for fabricating transparent conductive fiber involves doping ionic liquid into polymer matrix. However, low conductivity of ionic liquid renders the fiber inadequate for practical application. Herein, we developed a flexible transparent conductive fiber exhibiting high conductivity, and high transparency by coating Ag nanowires (AgNWs) onto thermoplastic polyurethane (TPU) fibers treated with air plasma. The specific synthesis processes are as follows: TPU fiber was cleaned in an ultrasonic bath using ethanol and deionized water respectively for 5 min each. The cleaned TPU fiber was treated by air plasma at 150 W for 3 min. The obtained fiber was then dip-coated in 2 mg•mL^-1 AgNWs ethanol dispersion for 1 min and dried in air for 5 min. After repeating 3 times of dip-coating process, the TPU@AgNWs transparent conductive fiber was prepared. The hydrophobicity of TPU impedes uniform adhesion and morphological stability of directly applied hydrophilic AgNWs conductive coatings on TPU fibers. Following plasma treatment, abundant hydrophilic groups are uniformly introduced onto TPU fiber surface. Water contact angle diminishes with the extended time of plasma treatment, verifies the hydrophilicity improvement of TPU fiber. X-ray photoelectron spectroscopy (XPS) reveals increasing C—O/C—N and N—O bond contributions derived of hydrophilic groups. These groups form hydrogen bonds with the polyvinyl pyrrolidone (PVP) coating on the AgNWs, resulting in a strong and uniform adhesion of the AgNWs layer to the TPU fiber substrate. The transparent conductive fiber achieves a conductivity of 10 S•cm⁻¹, which is 1000 times of the TPU@ionic liquid fiber, combined with a transparency exceeding 75%. After 14 d of ambient storage and 100,000 bending cycles, it retains over 90% of its initial conductivity. The as-prepared TPU@AgNWs transparent conductive fibers were weaved into a textile with luminescent fiber electrodes (a copper fiber successively coated BaTiO₃ dielectric layer, ZnS phosphor layer and polyurethane encapsulation layer) by an industrial rapier loom to prepare a textile display. The TPU@AgNWs transparent conductive fibers enable display luminance reaching 208 cd•m^-2, along with excellent washability and abrasion resistance.

Key words: transparent conductive fiber, textile display, Ag nanowire, thermoplastic polyurethane, plasma treatment