Fabrication of Superhydrophobic Copper Surface on Various Substrates for Roll-off, Self-Cleaning, and Water/Oil Separation

Abstract

Superhydrophobic surfaces prevent percolation of water droplets and thus render roll-off, self-cleaning, corrosion protection, etc., which find day-to-day and industrial applications. In this work, we developed a facile, cost-effective, and free-standing method for direct fabrication of copper nanoparticles to engender superhydrophobicity for various flat and irregular surfaces such as glass, transparency sheet (plastic), cotton wool, textile, and silicon substrates. The fabrication of as-prepared superhydrophobic surfaces was accomplished using a simple chemical reduction of copper acetate by hydrazine hydrate at room temperature. The surface morphological studies demonstrate that the as-prepared surfaces are rough and display superhydrophobic character on wetting due to generation of air pockets (The Cassie-Baxter state). Because of the low adhesion of water droplets on the as-prepared surfaces, the surfaces exhibited not only high water contact angle (164 ± 2°, 5 μL droplets) but also superb roll-off and self-cleaning properties. Superhydrophobic copper nanoparticle coated glass surface uniquely withstands water (10 min), mild alkali (5 min in saturated aqueous NaHCO3 of pH ≈ 9), acids (10 s in dilute HNO3, H2SO4 of pH ≈ 5) and thiol (10 s in neat 1-octanethiol) at room temperature (25-35 °C). Again as-prepared surface (cotton wool) was also found to be very effective for water-kerosene separation due to its superhydrophobic and oleophilic character. Additionally, the superhydrophobic copper nanoparticle (deposited on glass surface) was found to exhibit antibacterial activity against both Gram-negative and Gram-positive bacteria.

Water-Repellent Properties of Superhydrophobic and Lubricant-Infused “Slippery” Surfaces: A Brief Study on the Functions and Applications

“…35−37 In comparison, the SUB surface can provide a reliable and economic antiwetting performance, especially in the field of engineering materials, coating, and painting. 26,27 3.4. Antifogging Performance of the SUB and LIS Surfaces.…”

Highly efficient oil/water separation and excellent self-cleaning surfaces based on 1-triacontanol-polymerized octadecylsiloxane coatings

“…Moreover, self-cleaning ability as an important factor for reusable and antifouling in the practical use, there are only few reports studied the oil/water separation materials with self-cleaning ability [23,24].…”

Superhydrophobic surfaces with photocatalytic activity under UV and visible light irradiation

“…Many different strategies for fabricating artificial superhydrophobic surfaces have been reported in the literature over the last decade. These include distribution of hydrophobic nanoparticles on solid surfaces [5][6][7] and micro-and nano-structuring of flat surfaces combined with surface termination with hydrophobic molecules [8][9][10][11]. Superhydrophobic surfaces have drawn particular attention due to their unique self-cleaning behaviors, as dust particles on superhydrophobic surfaces can be swept away by water droplets on the surface [7,[12][13][14].…”

“…These include distribution of hydrophobic nanoparticles on solid surfaces [5][6][7] and micro-and nano-structuring of flat surfaces combined with surface termination with hydrophobic molecules [8][9][10][11]. Superhydrophobic surfaces have drawn particular attention due to their unique self-cleaning behaviors, as dust particles on superhydrophobic surfaces can be swept away by water droplets on the surface [7,[12][13][14]. Moreover, superhydrophobic surfaces have been demonstrated as anti-fouling [15][16][17] and corrosion-resistant in aqueous media [18,19].…”