Superhydrophobic Self-Cleaning Hierarchical Micro-/Nanocomposite Coating with High Corrosion Resistance and Durability

Abstract

Due to their special wetting properties, bioinspired superhydrophobic coatings are used to protect various materials. However, contamination with corrosive liquids or mechanical damage causes the loss of water repellency of many superhydrophobic surfaces. Therefore, it is imperative to develop chemically stable and durable superhydrophobic coatings. In this work, we report a straightforward method to fabricate a metal–organic framework (ZIF-8)/SiO2 with hierarchical micro-/nanostructures, whose surface hydrophobicity is induced by polydimethyl­siloxane (PDMS) modification. Notably, the surface of the resulting ZIF-8@SiO2/PDMS displays superhydrophobicity, together with a water contact angle (CA) of 157°. The superhydrophobic material is chemically stable, the water CA remaining above 150° even after exposure to a wide range of pH values (1–14) for 24 h. The electrochemical results showed that the coating exhibits a high corrosion potential (E corr = −0.321 V) and a very low corrosion current density (i corr = 1.442 × 10–11 A·cm–2) relative to an uncoated aluminum substrate (E corr = −0.711 V, i corr = 6.616 × 10–5 A·cm–2), indicating a high resistance to corrosion as a result of the coating. Also, electrochemical impedance spectroscopy showed that the charge transfer resistance is significantly increased by the coating. These results indicate that the ZIF-8@SiO2/PDMS coating with superhydrophobic properties has excellent corrosion resistance. In addition, the superhydrophobicity was proven for various droplets (i.e., water, tea, milk, coffee), an achievement related to the excellent self-cleaning performance: when the droplets roll off, surface contaminants are easily removed. The coating exhibited good mechanical properties, the CA being above 150° after 100 cycles of scrubbing with a pressure of 20 kPa. These excellent properties recommend the obtained superhydrophobic coating for various practical applications.

Efficient Removal of Cr(VI) by TiO2 Based Micro-Nano Reactor via the Synergy of Adsorption and Photocatalysis

“…The Cr(VI) removal capacity by various photocatalytic materials is summarized in Table 1, which indicates that the Z100T200 shows better catalytic performance. For Z100T200, the band gap reduced compared with TiO 2 , leading to higher photocatalytic property [42]. Meanwhile, the photo-electrons at CB of TiO 2 could transfer to HOMO of ZIF-8 to recombine with the holes according to the VB information.…”

One-Step Fabrication of a Functionally Integrated Device Based on Polydimethylsiloxane-Coated SiO2 NPs for Efficient and Continuous Oil Absorption

“…Second, the PDMS precursor was prepared by mixing the PDMS base and the curing agent in a 10:1 weight ratio. Then the PDMS precursor, SiO 2 NPs, and heptane solvent were mixed together in a dilution ratio 1 (i.e., 0.3 g SiO 2 NPs: 0.2 g PDMS: 20 mL heptane) [ 33 , 34 , 35 ], before an ultrasonic treatment for 15 min was conducted to form a suspension. The dilution ratio was 0.5, 1.5, 2, and 2.5 when 10, 30, 40, and 50 mL heptane was added with the same amount of SiO 2 NPs and the PDMS precursor ( Figures S2 and S3 ).…”

Facile Fabrication of PBS/CNTs Nanocomposite Foam for Electromagnetic Interference Shielding

“…The different modes of spherulite growth could be ascribed to the addition of CNTs, which induced the heterogeneous nucleation of PBS, increased the nucleation density of spherulites, and inhibited the growth of spherulites. [38,39]…”