Wearable Heated Fabrics with Hierarchically Self-Assembled Photothermal Nanoparticles Coatings for Thermotherapy Application

To prepare wearable heated fabric with effective photothermal conversion property for human thermotherapy, silver (Ag) and gold nanoparticles (Au NPs) with thermoplasmonic effect were hierarchically deposited on the cellulose fabric through spray-assisted self-assembly technique, and thus fabricated Ag/Au NPs composite-coated fabric with compactly arranged nanostructures. The surface morphology of Ag/Au NPs-coated fabric was observed by scanning electron microscope (SEM), the light absorption ability was characterized through ultraviolet–visible–near infrared (UV–Vis–NIR) spectra and the correspondingly calculated optical absorbed power, and the photothermal effect was monitored by photothermal conversion test under simulated and natural solar irradiation, respectively. The results showed that the different-sized Ag and Au NPs were distributed randomly on the surface of cellulose fibers, and the small Au NPs were deposited densely in the gaps between large-sized Ag NPs. The composite-coated fabric exhibited the characteristic plasmonic peaks from Ag and Au NPs and enhanced the spectral absorption ability in the UV–Vis–NIR wavelength range, and the surface temperature of the composite-coated fabric reached ~ 48 °C under solar irradiation of 1 kW m−2, and thus improved photothermal conversion performance with ΔT ~ 20 °C compared with pristine fabric. Furthermore, the composite coatings deposited on fabric displayed favorable photothermal stability under cyclic utilization and washing treatment, as wells as the good thermochromic performance for temperature indication. The exploration of the composite-coated fabric with photothermal effect provides a feasible strategy for wearable thermotherapy application.