Highly Flexible Superhydrophobic Poly(Urethane Acrylate) Film for Applications Requiring High Optical Transparency

Abstract

The importance of superhydrophobic surfaces has been potentially demonstrated in several applications such as anti-fouling, [4] self-cleaning, [5] antifriction, [6] oil/water separation, [7] microfluidics, [8] biomedical devices, [9] and solar cell protection. [10] However, most proposed superhydrophobic surfaces are nontransparent and inflexible, thereby restricting their use in certain applications such as smart screens for solar panels, camera lens, organic light-emitting diodes, safety goggles, and automobiles. [11] Therefore, research has focused on realizing a highly transparent, and flexible superhydrophobic (HTFS) surface to overcome these limitations, as well as the drawbacks of the current stateof-the-art flexible transparent films, and thus, expand the range of applications. A HTFS film requires an optimized surface roughness, a passivation layer comprising functional materials with low surface energy, and a transparent substrate. Recently, several polymer materials like polyethylene terephthalate (PET), [12,13] poly(methyl methacrylate) (PMMA), [14] polydimethylsiloxane (PDMS), [15] and poly(urethane acrylate) (PUA) [16,17] have been used to prepare transparent and flexible superhydrophobic films. For example, Teshima et al. fabricated a HTFS substrate via oxygen plasma treatment followed by the deposition of an organosilane hydrophobic coating. [13] Vourdas et al. prepared a nanotextured superhydrophobic transparent PMMA substrate using a high-density plasma processing method. [18] However, most PET-and PMMA-based studies conducted oxygen plasma treatment, which is not conducive to large-scale production. On the other hand, PDMS has been widely used to fabricate transparent and flexible superhydrophobic substrates owing to its high fidelity for microstructure development and rapid prototyping. However, it is difficult to prepare a thin PDMS film (tens of micrometers) as a freestanding film or deposit PDMS on other substrates because of its high viscosity and poor adhesion to other substrates. PUA presents excellent physicochemical and optical properties, such as high deformability, ultraviolet (UV) curability at room temperature, excellent impact strength, and high transparency in the visible region. Despite these beneficial features, to date, experimentally realizing a PUA-based superhydrophobic substrate has seen limited success because of its high surface energy. To the best of our knowledge, only three reports The present work elucidates the successful attempts toward the development of a highly transparent, flexible, and superhydrophobic (HTFS) film. The HTFS film is obtained by introducing graphene oxide (GO) into micropillar-patterned poly(urethane acrylate) (PUA), followed by siloxane functionalization via chemical vapor deposition. The fabricated SPG 2 film (siloxane-functionalized PUA incorporated with 0.1 wt% of GO) exhibits a water advancing contact angle, water receding contact angle, and sliding angle of 155.5 ± 0.3°, 143.4 ± 0.6°, and 9 ± 0.4°, respectively. The SPG 2 film also exhibit...

Enabling Antibacterial and Antifouling Coating via Grafting of a Nitric Oxide-Releasing Ionic Liquid on Silicone Rubber

“…Enhanced peak intensity was observed at 1733 and 1362 cm –1 due to the introduced Pro – anion. The above results confirm the successful preparation of PDIL-Br and PDIL-Pro. , XPS survey scan spectra (Figure S2) and the narrow scan model fit spectra of PDMS before and after grafting were determined for the C 1s , N 1s , and Br 3d peaks, respectively. On the surface of pristine PDMS, characteristic signals of carbon (∼285 eV), oxygen (∼533 eV), and silica (∼103 eV for Si 2p and ∼154 eV for Si 2s ) were clearly observed (Figure S2a).…”

Eco‐friendly UV‐curable polyurethane‐silica superhydrophobic coating with superb mechanical durability

“…Non‐wettable surfaces with surface tension <73 mN/m, water contact angles (CA) >150 ° , and sliding angles (SA) <10 ° are considered superhydrophobic (SH) 1 . Thanks to their tremendous potential applications such as self‐cleaning, 2 anti‐icing, 3 anticorrosion, 4 anti‐biofouling, 5 drag reduction, 6 waterproofing, 7 and oil/water separation, 8 there are a plethora of interest from academic to industrial communities in SH coatings.…”