Broadband antireflective superhydrophilic antifogging nano-coatings based on three-layer system

Abstract

The multifunctional nano-coatings with super-wettability, unique optical property, and excellent mechanical strength and weatherability are highly desirable due to their wide applications. However, up to now, it is still very difficult to balance the relationships among these properties due to structural confliction. In this work, the broadband antireflective superhydrophilic antifogging nano-coatings are successfully constructed based on three-layer system by a sequential dip-coating method. The coating of dendrimer-like mesoporous silica nanoparticles (DMSNs) as top-layer not only increases the roughness of coating surface to enhance the wettability, but also keep high transmittance of the coated glass slides. Simple chemical vapor deposition is performed to improve the mechanical stability of nano-coatings. The finally obtained glass slide with the optimal nano-coating has high transmittance (97.7% at the wavelength of 494 nm, and ca. 5.0% increase of mean transmittance in the visible wavelength range of 390–780 nm), superhydrophilic (WCAs after 0.5 s of spreading: 4.3°) anti-fogging behavior, and good mechanical strength. This work provides an exploration way about how to balance the structural parameters to obtain the multifunctional nano-coatings for optical devices and energy harvesting.