Carbon nanotube/waterborne polyurethane nanocomposites with light-to-heat conversion properties

Photothermal materials and coatings which can create temperature elevations under light irradiation can be utilized in various applications requiring remote heating. Here, multiwalled carbon nanotubes (MWNT) were incorporated into waterborne polyurethane (PU) to obtain photothermal coatings with light-to-heat conversion properties. Resulting PU-MWNT coatings were demonstrated to heat up to 80 °C under sunlight irradiation at 2 sunlight density for 18 min. Pseudomonas aeruginosa (P. aeruginosa) cells attached to surfaces coated with PU-MWNT nanocomposites were killed upon near infrared (NIR) light irradiation at 808 nm for 15 min, whereas the same cells attached to control neat PU-coated surfaces remained alive under the same irradiation conditions. Furthermore, a scratch of 1 cm width on the PU-MWNT coating was shown to be healed under 12 min of sunlight irradiation. The PU-MWNT nanocomposites have strong potential as photothermal coatings, which can be remotely heated with NIR light activation.