Superhydrophilic/superhydrophobic surfaces fabricated by spark‐coating

Abstract

In this study, the authors researched the preparations of superhydrophilic/superhydrophobic surfaces on commercial cup stock polyethylene coated papers by using sparked aluminum nanoparticles deposited on substrates through a sparking process. In this stage, the surface was porous and showed superhydrophilic properties. The samples were then annealed in air at various temperatures and some transformed to superhydrophobicity. It is well known that a suitable roughness in combination with low surface energy has been required to obtain superhydrophobic surfaces. Therefore, it is believed that during annealing process, when polyethylene is diffused from the substrate through the nanoparticle films and the superhydrophobic characteristics were created. The scanning electron microscope images showed that the film surfaces had a fluffy structure for both the as‐deposited and the annealed samples. However, the atomic force microscopy phase images showed completely different surface properties. Moreover, the X‐ray photoelectron spectroscopy spectra showed different surface chemical compositions. The experimental results revealed that the working temperature to produce superhydrophobic surfaces depended on the sparked film thickness. Furthermore, in order to prove the assumption explained above, glass and poly (methyl methacrylate) were also used as substrates.

Antireflective, photocatalytic, and superhydrophilic coating prepared by facile sparking process for photovoltaic panels

“…The average WCA was 42.0 ± 2.1°, 32.4 ± 1.0°, 14.5 ± 0.5°, 6.9 ± 0.3°, and 1.8 ± 0.2°, respectively, for scans that were repeated 1–5 times. The decrease in the WCA occurs because the nanoparticle films can increase the contact area between the water droplet and substrate and thereby reduce the contact angle 12 . The water droplets were completely flat when the scans were repeated 6–10 times, and the WCA was close to 0° (pictures not shown).…”

“…Furthermore, it does not generate toxic waste from chemical precursors or other chemical agents. The sparking process is a new synthesis method that can create porous nanostructured films with well-controlled thickness and uniform composition, as well as facilitate large-scale, one-step coating at a low cost 9 – 12 . It utilizes the sparking between two metal tips to form nanoparticulate films under atmospheric conditions so that an expensive vacuum system is not required.…”

Inducing Crystallinity of Metal Thin Films with Weak Magnetic Fields without Thermal Annealing

“…Thin film characterization was done by using an Atomic Force Microscope (Digital Instruments, Inc., Santa Barbara CA, USA) (AFM) in the tapping mode equipped with a standard Si tip and operated at a scan size of 1 × 1 µm 2 in air at room temperature. Detailed description of AFM characterization can be found in references [24,25]. where aluminium [25] and zinc [24] wires were sparked, and thin film produced.…”

“…Detailed description of AFM characterization can be found in references [24,25]. where aluminium [25] and zinc [24] wires were sparked, and thin film produced.…”