Ultraviolet-Durable Superhydrophobic Nanocomposite Thin Films Based on Cobalt Stearate-Coated TiO₂ Nanoparticles Combined with Polymethylhydrosiloxane

Abstract

Ultraviolet (UV)-durable superhydrophobic nanocomposite thin films have been successfully fabricated on aluminum substrates by embedding cobalt stearate (CoSA)-coated TiO 2 nanoparticles in a hydrophobic polymethylhydrosiloxane (PMHS) matrix (PMHS/TiO 2 @CoSA) using the sol–gel process. When compared to the sharp decrease of water contact angle (WCA) on the superhydrophobic PMHS/TiO 2 thin films, the PMHS/TiO 2 @CoSA superhydrophobic thin films exhibited a nearly constant WCA of 160° under continuous UV irradiation for more than 1 month. The designed scheme of the TiO 2 @CoSA core–shell structure not only increased the hydrophobic properties of the TiO 2 nanoparticle surface but also confined the photocatalytic efficiency of TiO 2 nanoparticles. A plausible model has been suggested to explain the UV-durable mechanism of the superhydrophobic nanocomposite thin films based on PMHS/TiO 2 @CoSA. Furthermore, the elongated lifetime in the exposure of the solar light imparts this superhydrophobic nanocomposite thin film with potential practical applications where UV-resistant properties are emphasized including corrosion-resistant building walls, anti-icing airplanes, self-cleaning vehicles, and so forth.

Silver–Polymethylhydrosiloxane Nanocomposite Coating on Anodized Aluminum with Superhydrophobic and Antibacterial Properties

“…The single peak at 2939 cm –1 at the high-frequency region can be assigned to the asymmetric stretching mode of −CH 3 groups in the PMHS molecule . At the lower-frequency region, the two peaks at 1270 and 764 cm –1 correspond to Si–CH 3 groups . Similarly, the peak at 1100 cm –1 can be linked to the asymmetrical stretching vibration of the Si–O–Si mode, while that around 800 cm –1 can be attributed to the symmetric bending mode of the Si–O–Si bonds .…”

“…However, in the absence of Ag-NPs, a lower CA of 123 ± 3.1° was obtained for PMHS coated on AAO. Indeed, we have shown in our previous contribution that a high water CA (∼152°) could only be achieved after an appropriate combination of PMHS molecule and nano–micro roughness induced by colloidal TiO 2 NPs . To improve the adhesive property of the AgP–NcAAO sample, RTV silicone, a well-known adhesive and hydrophobic silicone copolymer with water CA < 120°, was loaded into the Ag–PMHS nanocomposites.…”

“…27 At the lower-frequency region, the two peaks at 1270 and 764 cm −1 correspond to Si−CH 3 groups. 28 Similarly, the peak at 1100 cm −1 can be linked to the asymmetrical stretching vibration of the Si−O−Si mode, 29 while that around 800 cm −1 can be attributed to the symmetric bending mode of the Si−O−Si bonds. 30 The peak at 2162 cm −1 at the midfrequency region is assigned to the Si−H stretching mode.…”

Non-Fluorinated, Sustainable, and Durable Superhydrophobic Microarrayed Surface for Water-Harvesting

“…Moreover, it is important to study the behavior of these coatings under different conditions to understand and determine their durability. Hence, UV light resistance test [54] is carried out to determine the capability of the superhydrophobic surface to resist environmental conditions. After 300 min of UV light exposure (Figure 10), there was no remarkable difference in the WCA between the coating before the test and after 300 min under UV light exposure.…”

Highly Hydrophobic and Self-Cleaning Heat-Treated Larix spp. Prepared by TiO2 and ZnO Particles onto Wood Surface

“…Nano-TiO 2 is widely used in solar cells and photocatalysis; it is also used for improving fire resistance as well as the antifungal and antiweathering properties of wood. In these applications, the role of TiO 2 is directly determined by the morphological and the size of the particles [17].…”