Low surface energy polymers are especially well-suited to form superhydrophobic surfaces because they can be easily processed into a wide range of useful forms using techniques ranging from lamination to 3D printing. Additional functionality can be achieved by further modifying the surface structure and/or incorporating catalytically active particles. In this presentation, I will discuss different approaches to increasing the functionality of superhydrophobic surfaces for specific applications.
In one approach, nanoscale topography is formed in the surface of a fluoropolymer using a novel lamination-peeling mechanism. The nanoscale roughness, low refractive index, and hierarchical topography combine to impart anti-reflective properties, reducing reflections by more than 75%. These superhydrophobic surfaces exhibit anti-soiling behavior in the presence of condensed water owing to the high mobility of the solid-liquid-vapor triple contact line. Coalescence-induced jumping condensation can occur, even at large values of sub-cooling (ΔT > 70 K).
In a second approach photo-catalytic sensitizer particles are partially embedded into a surface created by 3D printing a polydimethylsiloxane, thereby enabling the generation of reactive singlet oxygen that can diffuse across the plastron and efficiently kill microbes while preventing direct contact of the catalyst with biofluids. By controlling the topography, stable superhydrophobic properties are achieved even with hydrophilic particles. Complete biofilm inactivation (>5 log killing) of Porphyromonas gingivalis, a bacterium implicated in periodontal disease, is achieved using a superhydrophobic singlet oxygen delivery device.
Alan Lyons received a B.Sc. in chemistry from Brown University and Ph.D. in polymer chemistry from Polytechnic University (now NYU-Tandon). He was a Distinguished Member of Technical Staff with the research division of Bell Laboratories and a founding member of Bell Labs Ireland. He joined the City University of New York, as a Professor in the Department of Chemistry in 2008. His work is focused on developing multi-functional materials with novel wetting, thermal and catalytic properties. He has authored over 45 publications as well as 38 issued patents. Based on this work, he has co-founded two companies: ARL Designs LLC, which develops advanced coatings for glass and metal; and SingletO2 Therapeutics LLC, which develops device for oral healthcare.