Phase Change Material based Protective Coatings

The accumulation of foreign contaminants on functional surfaces, whether ice on an airplane wing or disease-causing bacteria on medical devices, remains a hazardous problem for many essential industries, incurring yearly losses of billions of dollars worldwide. To address these challenges, researchers around the globe have made remarkable advancements in the development of synthetic surfaces which benefit from being repellant. Unfortunately, such coatings (e.g., superhydrophobic or lubricant infused surfaces) not only require unique surface treatments to operate but are also prone to failure in highly humid and freezing temperatures. The present dissertation reports a versatile design strategy for developing a library of phase change material-based compositions capable of trapping the latent heat released during water vapor condensation and thereby creating a slippery interface that curbs the adherence of various contaminants (ice to bacteria) applied to its surface. The complexity of the associated problems and the inherent breadth of the approach necessitates it to be split up into four modules. The first module establishes the fundamental mechanism to extensively delay the freezing of condensed droplets under frigid environmental conditions using phase change materials (also called phase switching liquids, PSLs). The second module investigates the performance limits of PSLs under different environmental conditions and delineates the factors which dictate their resulting performance. The third module aims to identify bio-friendly PSLs functioning under the same mechanism of trapping the condensational latent heat for devising adaptive materials capable of spanning versatile functionalities. Finally, the last module demonstrates how a diverse family of phase change material and cryoprotectant-based compositions can be engineered to be resistant against shear-flow and dissolution-driven material loss and thereby be utilized for the rational development of multifunctional protective coatings for real-world usage in demanding industrial applications.