Implementing Superhydrophobic Surfaces within Various Condensation Environments: A Review

Abstract

Steam condensation is omnipresent, and inevitable in many industrial processes. A classic example is seen within condensers that are used to liquify various gasses. In consequence, water‐vapor is eventually deposited upon the exterior of heat pipes that passively cool the gas to form a thin film of liquid. This macroscopic film is responsible for the degradation of heat transfer efficiencies. Liquid repellent surfaces can microscopically manipulate the hydrodynamics of formulating condensate to transition toward dropwise/jumping‐droplet condensation. This effect will save operating and maintenance costs of steam condensers within power‐plants, subsequently reducing emissions, operating power, and fuel consumption. However, the challenges associated with the stabilization of dropwise/jumping‐droplet condensation, especially at large subcooling temperatures and high supersaturation ratios, have prohibited the use of liquid repellent surfaces. This review aims to discuss recent improvements and understanding of dropwise/jumping‐droplet condensation surfaces on superhydrophobic surfaces. Numerous examples shall be included, showing experimental and numerical studies of various innovative properties of superhydrophobic structures. In addition, various fabrication techniques of superhydrophobic surfaces that are applicable within industrial systems are discussed. These topics are consolidated to provide guidelines for future research into dropwise/jumping‐droplet condensation on liquid repellent surfaces.

A Deep Learning Perspective on Dropwise Condensation

“…Condensation is an efficient mass‐transfer process observed in nature and is essential to many industrial applications such as thermoelectric and nuclear power generation, [ 1 ] water harvesting systems, [ 2 , 3 , 4 , 5 , 6 ] heat exchangers, [ 7 , 8 ] and desalination plants. [ 9 , 10 ] Condensation involves the nucleation of droplets on a surface that can lead to significant heat and mass transfer improvement depending on the droplet dynamics.…”

Hovering spreading rebound on porous superhydrophobic surface with active air plastron for rapid drop detachment

“…Active air plastron thus could help restore the superhydrophobicity in situ against dynamic environments. Also, previous studies revealed that condensation could influence the non-wetting feature of passive superhydrophobic surfaces, 41,42 the strategy developed here would be effective to reduce this effect.…”

Tribological Behavior of Bioinspired Surfaces

“…The pitcher plant, where insects slip into the pitcher and are then digested for food, served as the inspiration for the slippery surfaces depicted in Figure 12 [ 264 ]. Figure 12 shows the microscopic and macroscopic grooves over the surface, which are separated by ridges, providing hindrance to the lateral spread of water by enhancing the radial spread towards creating slippery surfaces [ 265 , 266 ]. A new class of liquid-repellent surfaces with self-cleaning capabilities can be created by the surface morphology of pitcher plants along with the microscopic and macroscopic grooves [ 267 ].…”