Ultrasonic Healing of Plastrons.

Superhydrophobic surfaces (SHS) exhibit a pronounced ability to resist wetting. When immersed in water, water does not penetrate between the microstructures of the SHS. Instead, a thin layer of trapped gas remains, i.

Super liquid repellent surfaces for anti-foaming and froth management.

Wet and dry foams are prevalent in many industries, ranging from the food processing and commercial cosmetic sectors to industries such as chemical and oil-refining. Uncontrolled foaming results in product losses, equipment downtime or damage and cleanup costs. To speed up defoaming or enable anti-foaming, liquid oil or hydrophobic particles are usually added.

Ultrafast Bubble Bursting by Superamphiphobic Coatings.

Controlling bubble motion or passively bursting bubbles using solid interfaces is advantageous in numerous industrial applications including flotation, catalysis, electrochemical processes, and microfluidics. Current research has explored the formation, dissolution, pinning, and rupturing of bubbles on different surfaces. However, the ability to tune and control the rate of bubble bursting is not yet achieved.

Surface Chemistry Enhancements for the Tunable Super-Liquid Repellency of Low-Surface-Tension Liquids.

Super-hydrophobic, super-oleo(amphi)phobic, and super-omniphobic materials are universally important in the fields of science and engineering. Despite rapid advancements, gaps of understanding still exist between each distinctive wetting state. The transition of super-hydrophobicity to super-(oleo-, amphi-, and omni-)phobicity typically requires the use of re-entrant features.

Cassie-Levitated Droplets for Distortion-Free Low-Energy Solid-Liquid Interactions.

Despite the rapid advent of superomniphobic materials, there is a lack of methodologies to accurately investigate the ultralow-energy interactions taking place on these interfaces. For instance, universally employed models such as the pendant droplet often fail to provide representative information on the wetting properties of superomniphobic surfaces. The delicate balance between the forces acting at the droplet-surface and droplet-needle interfaces can easily result in heavily distorted droplet profiles.

Ultraporous superhydrophobic gas-permeable nano-layers by scalable solvent-free one-step self-assembly.

Superhydrophobic materials with excellent humidity tolerance, high porosity and light transmittance are being investigated for numerous applications including moisture-sensitive catalysts and perovskite solar cells. Here, we report the one-step solvent-free synthesis of ultraporous superhydrophobic nano-layers by the on-the-fly functionalization of nanoparticle aerosols. Short exposure of surfaces to hot Mn3O4, ZnO and TiO2 aerosols results in ultraporous nanoparticle networks with repulsive dewetting state approaching ideal Cassie-Baxter superhydrophobicity.

Slippery Wenzel State.

Enhancing the mobility of liquid droplets on rough surfaces is of great interest in industry, with applications ranging from condensation heat transfer to water harvesting to the prevention of icing and frosting. The mobility of a liquid droplet on a rough solid surface has long been associated with its wetting state. When liquid drops are sitting on the top of the solid textures and air is trapped underneath, they are in the Cassie state.

Silicon surface structure-controlled oleophobicity.

Superoleophobic surfaces display contact angles >150 degrees with liquids that have lower surface energies than does water. The design of superoleophobic surfaces requires an understanding of the effect of the geometrical shape of etched silicon surfaces on the contact angle and hysteresis observed when different liquids are brought into contact with these surfaces. This study used liquid-based metal-assisted etching and various silane treatments to create superoleophobic surfaces on a Si(111) surface.

Dependence of macroscopic wetting on nanoscopic surface textures.

The hydrophobicity of a surface can be enhanced by physical textures. However, no existing theories of surface wetting can provide guidance to pinpoint the texture size requirement to achieve super/ultrahydrophobicity. Here, we show that the three-phase contact line tension, tau, is an important link to understand the dependence of macroscopic wetting on physical texture size in an ideal Cassie regime.

Hierarchical silicon etched structures for controlled hydrophobicity/superhydrophobicity.

Silicon surface hydrophobicity has been varied by using silane treatments on silicon pyramid surfaces generated by KOH anisotropic etching. Results demonstrated that by altering the surface hydrophobicity, the apparent contact angle changed in accord with the Wenzel equation for surface structures with inclined side walls. Hierarchical structures were also constructed from Si pyramids where nanostructures were added by Au-assisted electroless HF/H2O2 etching.

Biomimetic creation of hierarchical surface structures by combining colloidal self-assembly and Au sputter deposition.

Surfaces of hexagonally packed silica spheres have been functionalized with silanes containing different hydrocarbon or fluorocarbon chains. The resulting chemical and physical structures were studied to establish the effect of surface hydrophobicity on the measured contact angles on the rough surfaces. The results were used to assess the effects of surface modifications on the parameters in the Cassie equation.