Robust carbon nanotube composite coatings for perfect absorption in harsh environmental applications

Abstract

We have successfully developed a nearly perfect absorber coating designed for extreme environmental conditions, utilizing a spray coating process that facilitates easy, cost-effective and large-scale production. The coating is formulated with carbon nanomaterials, enhanced by the incorporation of epoxy resin-coated carbon nanotubes that serve as a binding agent within the carbon black particle matrix. This strategic integration effectively 'freezes' the micro- and nanostructures of the surface, thereby substantially improving the coating's durability and stability. The coating delivers omnidirectional high absorption efficiency, exceeding 99.9 % across a broad wavelength range from 400 nm to 20 μm. It exhibits excellent adhesion and abrasion resistance, ensuring the maintenance of its absorptive performance under extreme conditions such as high and low temperatures, UV radiation, water impact and prolonged outdoor exposure. Carbon nanotubes have demonstrated their effectiveness as ideal connecting materials for perfect absorber coatings and their application has paved the way for new opportunities in the development of smart coatings. This robust and stable perfect absorber coating addresses the theoretical mechanical limitations inherent in conventional perfect absorber, significantly expanding their potential applications.