The Effect of Mixed Hydrophilic and Hydrophobic Surfaces on Frost Nucleation and Growth

Abstract

The purpose of this research is to test hydrophilic, hydrophobic, and mixed hydrophobic and hydrophilic (biphilic) surfaces to see how theses surfaces affect frost nucleation and growth. Frost forms when humid air comes into contact with a surface that is below the dew point and freezing temperature of water. Many engineering systems are hindered by frost, such as aeronautics, refrigeration, and electrical transmission wires. Most recent research on frost formation has looked at making superhydrophobic materials, which lower the freezing point and increase the frost formation time. These materials are very dependent on operating conditions and surface roughness, which fluctuate often. A hydrophobic surface delays frost growth more than a hydrophilic surface and also creates a taller, less dense frost layer than the hydrophilic surface. Our hypothesis is that a biphilic surface will be better at slowing the frost formation process as well as creating a less dense frost layer. The water in the air will preferentially condense on the hydrophilic areas, thus controlling where the nucleation will first occur. This could help to control the size, shape, and location of the frost nucleation.

Supercooled Water Drops Do Not Freeze During Impact on Hybrid Janus Particle-Based Surfaces

“…Combination of both hydrophilic and hydrophobic properties in one material can lead to the synergism of properties and effects. This idea can be realized through surfaces with chemical heterogeneity. − For instance, Van Dyke et al showed that chemical heterogeneity, created on surfaces by photolithography in combination with the modification of a hydrophobic substrate with hydrophilic octadecayltrichlorosilane, allowed for a suppression of the freezing temperature of water, freezing time delay, and control of coalescence dynamics. , Murase et al showed a reduction of ice adhesion and prevention of snow accretion on nanoscale surfaces based on organopolysiloxane modified with lithium …”