A Scalable Haze‐Free Antireflective Hierarchical Surface with Self‐Cleaning Capability

Abstract

The lotus effect indicates that a superhydrophobic, self-cleaning surface can be obtained by roughening the topography of a hydrophobic surface. However, attaining high transmittance and clarity through a roughened surface remains challenging because of its strong scattering characteristics. Here, a haze-free, antireflective superhydrophobic surface that consists of hierarchically designed nanoparticles is demonstrated. Close-packed, deep-subwavelength-scale colloidal silica nanoparticles and their upper, chain-like fumed silica nanoparticles individually fulfill haze-free broadband antireflection and self-cleaning functions. These double-layered hierarchical surfaces are obtained via a scalable spraying process that permits precise control over the coating morphology to attain the desired optical and wetting properties. They provide a "specular" visible transmittance of >97% when double-side coated and a record-high self-cleaning capability with a near-zero sliding angle. Self-cleaning experiments on photovoltaic devices verify that the developed surfaces can significantly enhance power conversion efficiencies and aid in retaining pristine device performance in a dusty environment.

Chirality‐Induced Spin Selectivity of Chiral 2D Perovskite Enabling Efficient Spin‐Dependent Oxygen Evolution Reaction

“…A patterned sample was annealed to promote adhesion for several hours in an oven at 50 °C (Figure S19, Supporting Information). [51] To achieve superhydrophobicity, the patterned sample was treated with 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (HTMS, Sigma-Aldrich) of 5 wt% solution in hexane (Duksan Pure Chemicals, Korea) using a spraying process (similar to the nanostructuring process), followed by additional annealing at 50 °C in an oven. Finally, the superhydrophobic/hydrophilic patterned sample was realized after careful removal of the Kapton tape.…”

Biomimetic Superhydrophobic Materials Construct from Binary Structure: A Review on Design, Properties, and Applications

“…Furthermore, the material undergoes almost no degradation even after a long-term compressive cycle between 0 and 90% strains. In 2022, Oh et al [222] designed a superhydrophobic surface which combines the antireflective and self-cleaning properties via hierarchically engineered nanoparticles. The self-cleaning property and broadband antireflection are separately carried out by chain-like fumed silica nanoparticles and their lower closely packed, deep subwavelength scale colloidal silica nanoparticles.…”

Recent Advances on the Abrasion Resistance Enhancements and Applications of Superhydrophobic Materials

“…[31,32] However, it was reported that the superhydrophobic materials prepared by most methods have poor abrasion resistance when damaged by external pollution or external force, which greatly limited the development and application of superhydrophobic materials. [33][34][35][36][37] In order to solve these problems, plenty of scholars have proposed different methods to improve the abrasion resistance of superhydrophobic surfaces, [38][39][40] such as reasonably designing the micro-nano structures and selecting materials, [41][42][43] optimizing the preparation process, [44,45] and the proportion of materials. [46][47][48][49][50] Although researches improving superhydrophobic abrasion resistance have made considerable progress, there are still many shortcomings, such as the lack of widespread applications.…”