AsianScientist (Nov. 17, 2016) – A team of researchers at the Pohang University of Science and Technology (POSTECH) led by Professor Dong Sung Kim has found an elegant, cost-effective, and environmentally friendly method of applying a superhydrophobic layer to objects by using commercially available salt particles, polydimethylsiloxane (PDMS), and water. Their results have been published in Applied Surface Science.
Superhydrophobic surfaces have attracted global attention due to their water-repellant characteristics and wide variety of applications, such as anti-icing, anti-sticking, and self-cleaning surfaces. In nature, one can observe superhydrophobicity on a lotus leaf, which is why it is sometimes described as the ‘lotus effect.’ The lotus leaf has microscopic protrusions on its surface which minimizes adhesion. As a result, water droplets, along with any dirt particles on the surface, simply roll right off the leaf.
There has been intensive research into applying the ‘lotus effect’ to other surfaces via simulating similar micro- and nanoscopic surface architectures. However, existing methods of applying a superhydrophobic layer required complicated procedures, expensive equipment and/or harsh chemicals.
Kim’s research team has successfully overcome these barriers by utilizing a salt-dissolution-assisted etching process. Taking advantage of the fact that salt readily dissolves in water, the team exposed a salt-particle-embedded PDMS surface to an aqueous environment. The remaining PDMS surface becomes roughened with micro/nano-hierarchical topography which satisfy the standards of superhydrophobic surfaces. Furthermore, this process can readily be applied to large or three-dimensional surfaces.
The article can be found at: Choi et al. (2016) Facile and Cost-effective Fabrication of Patternable Superhydrophobic Surfaces via Salt Dissolution Assisted Etching.
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Source: Pohang University of Science and Technology ; Photo: Pixabay.
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