An examination of the anti-icing mechanisms of charged polymer coatings

The formation and adhesion of ice onto surfaces is a critical issue towards the continued operation and safety of aircraft, wind turbines, maritime vessels, heat exchangers, power and telecommunications network cables, etc. Combating ice adhesion has historically relied on active methods, through heating, applying freezing point depressants, or most obviously: the mechanical removal of ice itself. Yet, the more passive approach of anti-icing coatings, has attracted significantly attention recently, given the inevitable nature of ice formation. Therefore, this research aims to shed light on the mechanisms of ice adhesion on charged polymer coatings, which have previously been largely inferential. To this end, I have developed a home-built ice adhesion test apparatus to measure the adhesion strength of ice on various surfaces. The design of charged polymer coatings has been a principle component of this research, and its efforts have led to a widely tunable system, to produce surfaces with variable chemical and coating structures.
These abilities have allowed the thorough investigation of ice adhesion onto charged polymer coatings, with variable counterion, polymer charge, and crosslink density. Observed variations in anti-icing behaviour suggested a mechanism based on the physical state of hydration water, which was confirmed using two independent methods: TIR Raman spectroscopy and a combination of ellipsometry and differential scanning calorimetry. Additionally, the magnitude of the ice adhesion strength at low temperatures was found to be correlated to a fraction of “non-freezable” water. Mechanistic insights gained from this research can be used to efficiently design future anti-icing coatings.