2015-054 – Nanopatterned Surfaces to Accelerate Freezing and Increase Water Collection on a Surface and to Reduce the Final Frost Height and Modify the Crystalline structure

Frost forms when humid air comes into contact with a surface that is below the dew point and freezing temperature of water. Frost formation can have severe negative consequences. Many engineering systems such as aeronautics, refrigeration, and wind turbines are hindered by frost. The ability to prevent frost formation and changing the crystalline structure of the frost particles, may have the ability to provide benefit in many industrial processes such as improving the energy efficiency of refrigeration and cooling systems and increasing safety in aeronautics by preventing ice formation on the wings of planes. A significant amount of research has been conducted on hydrophobic and hydrophilic materials to delay frost formation. Hydrophilic surfaces freeze closest to the freezing temperature of water. Hydrophobic surfaces on the other hand can suppress freezing by a few degrees. Researchers at Kansas State University have developed a novel, patent pending biphilic, nanopatterned surface preparation method that has the ability to slow frost formation and create a less dense frost layer on the surfaces to which it is applied. The biphilic, nanopatterned surface allows for the suppression of freezing at temperatures 6*K below the freezing temperature of water at 60% relative humidity. The overall research was conducted at three different relative humidities. The biphilic, nanopatterned surface allows for droplets of water to be constrained thereby forcing them into a specific pattern, different than the pattern they would form if not constrained. This constraint provides control over the coalescence of the water droplets. As droplets become larger, it takes more energy for them to freeze, slowing the process. In addition to suppressing freezing, the technology also affects the frost height and formation. The frost/ice that forms is not like all other ice. Many believe that ice is just ice. However, this technology creates frost formations that are not intertwined and do not touch. This is beneficial as the ice becomes transparent and contains gaps, which may provide for benefits such as allowing for uninterrupted signal transfer in communications applications in cold icy environments, as one example. Sarah Nolting snolting@ksu.edu 785-532-3910