Excellent floating and load bearing properties of superhydrophobic ZnO/copper stearate nanocoating

- Superhydrophobic coating comprised of ZnO/copper stearate was fabricated.
- The ZnO/copper stearate nanocoatings showed a water contact angle of 161°.
- The ZnO/copper stearate nanocoatings displayed excellent floating characteristics.
- The superhydrophobic nanocoatings showed superior load bearing properties.

The development of superhydrophobic materials is rapidly increasing due to their diverse applications such as self cleaning, oil-water separation, aquatic robotics, and so on. In this study, we developed a superhydrophobic coating comprising of porous ZnO nanoparticles and copper stearate (CuSA2) via a cost effective spray coating method. Physico-chemical characterizations such as X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscope, and elemental mapping were used to understand the crystallinity, bonding nature, morphology and distribution of the ZnO/CuSA2 coatings. Superhydrophobic nature of the bare CuSA2 coating measured through goniometer was found to be more than 151°, further it was enhanced to around 161° by increasing the weight percentage of ZnO. The ZnO/CuSA2 superhydrophobic coatings showed excellent super buoyancy characteristic as evidenced by their floating nature in water over a prolonged time. Further, experiments on maximum load bearing capacity of the ZnO/CuSA2 coatings were examined by placing stapler pins on their surface and the effect of deposition time on the load bearing capacity has been investigated in detail. The experimental results showed that the superhydrophobic nature of ZnO/CuSA2 coating with excellent floating characteristics and higher load bearing capacity may find a wide range of future applications in man-made water floating robots.

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