Transparent UV-Cured Polyurethane–Surfactant Coatings with Antifogging Properties

Abstract

Fogging on optical devices may severely impair vision, resulting in unacceptable adverse consequences. Transparent antifogging coatings play an important role in daily life, because they can effectively enhance transmission of light and meanwhile prevent water condensation considerably. Herein, highly transparent antifogging polyurethane coatings are designed and fabricated via a UV-assisted cross-linking method. Initially, isophorone diisocyanate, poly(ethylene glycol) (PEG), and 2,2′bis(hydroxymethyl)butyric acid (DMBA) were thermally polymerized to obtain a series of amphiphilic polyurethane prepolymers. Afterward, polyurethane prepolymers were end-capped by various surfactants (OP-x) and pentaerythritol triacrylate (PETA). Upon photoirradiation, the UV-cured polyurethane coatings with the cross-linking structure were obtained. Subsequently, the polyurethane coating has a hierarchical surface due to microphase separation. The wettability of coatings could be mainly attributed to the cooperative effect between the hierarchical surfaces and the hygroscopicity of the surfactant molecules. The polyurethane coating enables water to rapidly spread out, fulfilling the enhanced antifogging function (without forming water droplets). This antifogging material may find potential application in microdevices and engineering systems that operate in a cold or humid environment.

Double cross-linked transparent superhydrophilic coating capable of anti-fogging even after abrasion and boiling

“…[1][2][3] Due to the unique phase structure and a variety of interfacial functional groups in polymers, composite organic polymer-inorganic hybrid materials at the molecular level exhibit unique properties compared with simple hybrid materials. 4,5 In water dispersion systems, due to their characteristics of long molecular chains, adjustable structure, and easy introduction of polar groups (such as -COOH, -SO 3 H and -NH 2 ), organic polymer, and inorganic oxide particles can provide steric hindrance and electrostatic repulsion for particles through physical adsorption, thus improving the dispersion and stability of the system. 6,7 In this context, cross-linking of inorganic NPs with organic polymers has been the focus of attention since 2000.…”

Fabrication of Robust Carbon Dots Containing Coatings with UV-Shielding, Light Conversion, and Antifogging Multiple Functions

“…Notably, there are no observable characteristic peaks associated with aldehyde groups (2820–2720 and 1735–1715 cm –1 ) in these spectra. , Additionally, the stretching vibration of the amide bond is indicated by the peak at 1633 cm –1 , which resulted from the reaction of carboxyl and amino groups to form CDs. − The spectra clearly indicate the presence of peaks at about 1400 cm –1 , which correspond to the skeletal stretching vibration of the CD aromatic structure. Moreover, the characteristic peak of carboxyl groups appearing at 914 cm –1 is attributed to the nonplane rocking vibration caused by two associated hydroxyl groups. , The inset spectra indicate that the increase of PVA concentration results in a corresponding augmentation of hydroxyl groups, which would enhance the antifogging performance attributed to its hygroscopic properties. − …”

Bioinspired Photoelectronic Synergy Coating with Antifogging and Antibacterial Properties

“…The contact angle of PTPP-6 coated glass decreased from 55.7 to 8.5° in 15 s. Meanwhile, the rapid spreading of water droplets on the surface was also demonstrated by the rapid increase of Δ D / D 0 with time (Figure d). Afterward, the volume of the water droplet was measured according to the geometrical relations (Figure d): V false( t false) = π r 2 false( t false) h false( t false) false( 2 + cos 0.25em θ false( t false) false) 3 false( 1 + cos 0.25em θ false( t false) false) where V ( t ) is the volume of the water droplet, r ( t ) is the wetting radius of the droplet, h ( t ) is the maximum height of the droplet, and θ( t ) is the contact angle of the water. The volume of water droplets decreased slightly over 16 s, and after blow-drying, the mass of the PTPP-6-coated glass increased slightly, which proves that the moisture of the water droplets is absorbed by the PTPP-6 coating.…”