title: Durable Lotus-effect surfaces with hierarchical structure using micro- and nanosized hydrophobic silica particles.
abstract: Surfaces with a very high apparent water contact angle (CA) and low water contact angle hysteresis (CAH) exhibit many useful characteristics, among them extreme water repellency, low drag for fluid flow, and a self-cleaning effect. The leaf of the Lotus plant (Nelumbo nucifera) achieves these properties using a hierarchical structure with roughness on both the micro- and nanoscale. It is of great interest to create durable surfaces with the so-called "Lotus effect" for many important applications. In this study, hierarchically structured surfaces with Lotus-effect properties were fabricated using micro- and nanosized hydrophobic silica particles and a simple spray method. In addition, hierarchically structured surfaces were prepared by spraying a nanoparticulate coating over a micropatterned surface. To examine the similarities between surfaces using microparticles versus a uniform micropattern as the microstructure, CA and CAH were compared across a range of pitch values for the two types of microstructures. Wear experiments were performed using an atomic force microscope (AFM), a ball-on-flat tribometer, and a water jet apparatus to verify multiscale wear resistance. These surfaces have potential uses in engineering applications requiring Lotus-effect properties and high durability.
authors: Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue, Columbus, OH 43210-1142, USA.
authors: Daniel
authors: D
authors: Ebert
authors: Bharat
authors: B
authors: Bhushan
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D055616:Microtechnology; D053758:Nanoparticles; D031653:Nelumbo / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D014867:Water; D012822:Silicon Dioxide