Superhydrophobic anti-ultraviolet films by doctor blade coating

Abstract

This article reports a scalable technology for fabricating polymer films with excellent water-repelling and anti-ultraviolet properties. A roll-to-roll compatible doctor blade coating technology is utilized to prepare silica colloidal crystal-polymer composites. The silica microspheres can then be selectively removed to create flexible self-standing macroporous polymer films with crystalline arrays of pores. The void sizes are controlled by tuning the duration of a reactive ion etching process prior to the removal of the templating silica microspheres. After surface modification, superhydrophobic surface can be achieved. This study further demonstrates that the as-prepared transparent porous films with 200 nm of pores exhibit diffraction of ultraviolet lights originated from the Bragg's diffractive of light from the three-dimensional highly ordered air cavities.

Dragonfly-Wing-Inspired Inclined Irregular Conical Structures for Broadband Omnidirectional Antireflection Coatings

“…In this study, the conical-structure-covered PET substrate was placed in a vacuum oven with an open vial containing (tridecafluoro-1,1,2,2-tetrahydrooctyl)­trichlorosilane. The fluorosilane molecules were vaporized at 60 °C and reacted with the hydroxyl groups on the conical structures. , After 1.5 h, the PET substrate was transferred to another vacuum oven, which was evacuated to volatilize any unreacted fluorosilane molecules remaining on the conical structures.…”

Controlling disorder in self-assembled colloidal monolayers via evaporative processes

“…A closely related technique to dip-coating is drag-coating, or 'doctor-blade' coating, which is the horizontal counterpart to dip-coating. It similarly has found a use for coating substrates with biomolecules, [142][143][144][145] polymers, [146][147][148] and particles. [149][150][151] In this set-up, a small volume of the coating solution placed between the substrate and a blade is guided across the substrate.…”

Designed Assembly and Integration of Colloidal Nanocrystals for Device Applications

“…d) A schematic illustration showing the knife‐over‐edge process, which is a modified version of doctor blading that is compatible with the roll‐to‐roll process. b) Reproduced with permission . Copyright 2014, American Institute of Physics.…”

“…As shown in Figure b, doctor blading produces relatively thick NC films (up to several micrometers) . For example, the process has been employed to obtain several‐micrometer‐thick TiO 2 NC layers in dye‐ or QD‐sensitized solar cells, or electrodes made by conducting NCs (Figure c) .…”