Sprayable Ultrablack Photothermal Superhydrophobic Coatings for Anti-Icing Applications

Abstract

“Three birds with one stone” strategies for materials that simultaneously optimize ultrablack and photothermal superhydrophobic multifunctional integrity are expected to achieve a proper balance under extreme conditions, such as deep space exploration. Here, based on the combination of nanoscale structural and molecular composition design, the gradient hierarchically sandwich-like three-layered coating structures composed of carbon black resin bottom and porous middle layer and SiO2 top layer are designed through three steps all sprayed room temperature route. The effects of carbon black content and interface composition on adhesion, morphology, hydrophobicity, and light absorption properties of the coating were investigated. Remarkably, the proposed “light-capturing” porous architecture through cation−π interactions salt template route improved the light contact interface of air/adsorbent, and the finite-difference time-domain confirmed the optical/electrical field excitation of multiple higher-order resonances and thus enhanced scattering intensity, resulting in solar-weighted absorptance of 98.60% within the wavelength range of 200–2500 nm. Moreover, the freezing time of the droplets was delayed to 600 s at −20 °C, which is 12 times longer than that of the aluminum blank substrate, and it is 2.2 times superior to the previously reported antifreezing time of 271 s for CNT coatings. The all sprayed salt template method has potential for large-scale preparation of carbon- and inorganic resin-based ultrablack superhydrophobic photothermal coatings with multifunctional integrity by adjusting the architectures of compositional gradients at the nanometer and molecular scale under extreme conditions.