Modification of nanostructured fused silica for use as superhydrophobic, IR-transmissive, anti-reflective surfaces

• Published in: Optical materials Vol. 54; pp. 195 - 199
• Main Authors: Boyd, Darryl A., Frantz, Jesse A., Bayya, Shyam S., Busse, Lynda E., Kim, Woohong, Aggarwal, Ishwar, Poutous, Menelaos, Sanghera, Jasbinder S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-04-2016
• Subjects: Anti-reflection; Contact; Eyes; Fused silica; Infrared; Infrared transmission; Moth eye; Moths; Nanostructure; Near infrared radiation; Substrates; Superhydrophobic; Superhydrophobic; Infrared transmission; Fused silica; Moth eye; Anti-reflection
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2016.02.035

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•Fused silica substrates are modified, making them superhydrophobic (CAs >170°).•The modified substrates maintain optical transparency and anti-reflectance character.•Modified substrates maintain superhydrophobic character after seawater incubation.
In order to mimic and enhance the properties of moth eye-like materials, nanopatterned fused silica was chemically modified to produce self-cleaning substrates that have anti-reflective and infrared transmissive properties. The characteristics of these substrates were evaluated before and after chemical modification. Furthermore, their properties were compared to fused silica that was devoid of surface features. The chemical modification imparted superhydrophobic character to the substrates, as demonstrated by the average water contact angles which exceeded 170°. Finally, optical analysis of the substrates revealed that the infrared transmission capabilities of the fused silica substrates (nanopatterned to have moth eye on one side) were superior to those of the regular fused silica substrates within the visible and near-infrared region of the light spectrum, with transmission values of 95% versus 92%, respectively. The superior transmission properties of the fused silica moth eye were virtually unchanged following chemical modification.