There is an abundance of plant surfaces in nature, which inspires scientific community to replicate and prepare artificial superhydrophobic surfaces. However, most of these studies are limited to low-aspect-ratio structures as found in petals and leaves. In this study, the authors chose Canna indica, a garden plant belonging to Cannaceae family, as a model plant. The C. indica seedpods possess high-aspect-ratio multiscale structures and also show superhydrophobic behavior. These high-aspect-ratio hierarchical structures as found in C. Indica seedpod were then successfully replicated by replica molding in different polymers such as poly(dimethylsiloxane) (PDMS) and resorcinol-formaldehyde (RF)based xerogel. These biomimicked polymer surfaces exhibit superhydrophobicity as confirmed by water contact angle measurement. The original seedpod shows water contact angle of 151°, while negative PDMS and RF gel replica with high-aspect-ratio structural patterns show water contact angle of 146 and 155°, respectively. Thus, the biomimetic approach depicted here not only allows the facile fabrication of high-aspect-ratio structures over a large area but also provides a low-cost alternative to produce superhydrophobic polymer surfaces. Bioinspired, Biomimetic and Nanobiomaterials Volume 3 Issue BBN1 Biomimicked high-aspect-ratio hierarchical superhydrophobic polymer surfaces Mattaparthi and Sharma Pages 4-9
Liquid-repellent surfaces are beneficial for improving corrosion resistance, anti-biofouling, anti-icing, and reducing material sticking in food, beverages, cosmetics, and medical industries. However, limited research data are available on fabricating sewage water-repellent surfaces, which should repel suspended organic/inorganic and biological matter in addition to water. Herein, we unveil the sewage water repellency and superhydrophobicity of magnetic silicone composites and poly-(dimethylsiloxane) (PDMS). Hexagonally arranged microconical pillars (Wenzel roughness of 1.2−2.4) were printed via hot embossing and replica molding methodologies. High static contact angles of ∼160°, low contact angle hystereses of ∼5°, and low roll-off angles of ∼5°were achieved. At least 30 textured silicone composites were fabricated by successively hot embossing from a single custom-made and durable commercializable Ni−steel mold. All of them demonstrated excellent replication efficiency and retained superhydrophobicity and sewage water repellency as a function of embossing cycles. Furthermore, sewage water and deionized water droplets bounced off the silicone composite surface for a Weber number of up to 149, revealing a robust Cassie configuration. Furthermore, textured surfaces retained under-sewage water phobicity for up to 24 h, when submerged at 3 cm depth (0.3 kPa gauge pressure), wherein coated and untextured surfaces have failed just within 15 min, i.e., covered by a liquid film or sticky droplets. Also, textured surfaces inhibited the growth of the Escherichia coli bacterium, while a huge biofilm was observed on the untextured region. Briefly, this is the first demonstration of a one-step, upscalable, and facile hot embossing methodology to manufacture sewage water-repellent silicone composite and PDMS surfaces.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.