Superhydrophobic self-cleaning antireflective coatings on Fresnel lenses by integrating hydrophilic solid and hydrophobic hollow silica nanoparticles

Abstract

Superhydrophobic self-cleaning antireflective coatings were fabricated on Fresnel lenses by integrating solid silica nanoparticles (SSNs) and stearic acid (STA) and 1H,1H,2H,2H-perflurooctyltriethoxysilane (POTS) co-modified hollow silica nanoparticles (SPHSNs) via spin-and spray-assembly without any high temperature pre-or post-treatment. Transmission electron microscopy (TEM) was used to observe the morphology and structure of nanoparticles. Transmission spectra were recorded using a UV-Vis-NIR spectrophotometer. Surface wettability was studied by an automatic contact angle/interface system.Condensation performance of the Fresnel lenses was studied by measuring the focal length and the powers before and after being focused. The (SSNs) 1 /(SPHSNs) 2 coating turned out to simultaneously demonstrate excellent superhydrophobic self-cleaning and antireflective properties, which has a maximum transmittance of 99.0% and average transmittance of 98.5% in the wavelength range of 400-800 nm, and the condensing efficiency of the coated Fresnel lens has also been significantly improved. The surface morphology and structure of coatings were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The effects of surface morphology and structure on the optical and wetting properties of coatings were also discussed. The density of SPHSNs on the coating surface was considered to significantly influence both the light transmission and hydrophobicity of coated Fresnel lenses.

Rapid and Repeatable Self‐Healing Superoleophobic Porous Aluminum Surface Using Infiltrated Liquid Healing Agent

“…Inspired by nature, many efforts have been made in the last two decades to develop artificial superhydrophobic surfaces on engineering materials for various practical applications, such as self‐cleaning, anti‐icing, anticorrosion, and fluid drag reduction . The first artificial superhydrophobic surface was reported in 1996 by Onda et al, who demonstrated a superhydrophobic surface of alkylketendimer with fractal surface morphology exhibiting a water contact angle as high as 174°.…”

Femtosecond laser ablation of transparent microphotonic devices and computer-generated holograms

“…(e, h) 2D views of grating diffraction in a semi-transparent globe using 533 and 450 nm beams at normal incidence illumination (scale bar= 2 cm). (f, i) The angle of diffraction pattern from the grating illuminated normally at λ=450 and 533 nm.To simulate the diffraction effect, the Geometrical Theory of Diffraction GTD was used[53]. The effect of the two-dimensional groove was modeled with a two-dimensional phase modulation in a plane.…”

Sol–gel preparation of moisture-resistant antireflective coatings from novel hollow silica nanoparticles

“…However, the additional removal step of sacrificial templates usually requires high temperature, which is undesirable for certain polymer substrates, and raises environmental and energy issues. The third one is to combine improved hydrophobicity with closed pore structure [25][26][27]. Unfortunately, the above organic-modified surfaces required extra-organic reaction using fluoro-materials on nanoparticles and could be difficult to control the surface characteristics.…”