A porous superhydrophobic surface with active air plastron control for drag reduction and fluid impalement resistance

Abstract

Robustly sustaining the air plastron by active air pressure control through a porous superhydrophobic surface for high liquid impalement resistance.

Effect of nano‐size nodular structure induced by CNT‐promoted phase separation on the fabrication of superhydrophobic polyvinyl chloride films

“…In this case, by evaporating the more volatile solvent molecules (THF), the phase separation induced between polymer chains and the less volatile nonsolvent molecules (ethanol) in the casted film. The promising role of surface porosity in achieving a superhydrophobic property has been previously reported 27,28 . The higher magnification image, shown in Figure 3B, indicates that the morphology is comprised of PVC strands with the submicron diameter, which are covered by polymer spheres with diameters in the submicron scale.…”

“…property has been previously reported. 27,28 The higher magnification image, shown in Figure 3B, indicates that the morphology is comprised of PVC strands with the submicron diameter, which are covered by polymer spheres with diameters in the submicron scale. Such evenly distributed interconnected nodular morphology has been previously reported for phase separation-induced superhydrophobic films.…”

The challenges, achievements and applications of submersible superhydrophobic materials

“…As elaborated earlier in Section 4.1, high water pressures and/or pressure fluctuations can displace trapped air and a Cassie-Wenzel transition occurs. 45,57,[139][140][141] Starting from this definition, some routes have been developed to overcome this issue and enhance underwater stability. These routes can be classified into three major categories and are discussed with detailed examples in this section.…”

“…In this case, the target is to record higher failure/ breakdown pressures than what would be achieved solely by optimising design/fabrication conditions. 115,141,146,147 Some researchers reported the ability to adjust the plastrons pressure in response to changing water pressure (by changing the depth of submersion, and/or applying flow, etc.). Others reported controlling the gas-solubility of water to decrease air diffusion from plastrons.…”

“…Therefore, alternative approaches are required, one of these methods is the control of the plastrons pressure, adjusting it in response to the increased water pressure. 115,141,146,147 Other methods include operating under air-saturated water flow, 174 and heating the surface to create a stable solid-vapour interface. 29,57 The following section will discuss these approaches and how they enhance plastrons' lifetime.…”