Intelligent de-icing epoxy coating surface using bionics secreting oil microcapsules

Abstract

Ice on the surface of outdoor equipment or aircraft under low temperatures often brings serious consequences. Functional coating materials with intelligent de-icing performance have become one of the research hotspots in materials science. Inspired by the bionic de-icing structure of penguin feather secretion oil, the aim of this work was to design and prepare an environmental-friendly intelligent de-icing epoxy coating surface with bionic microcapsule. The core material of the microcapsules is the hydrophobic oily liquid of glyceryl tri(2-ethylhexanoate) (C27H50O6), which can be secreted from and the hexamethoxymethyl melamine resin (HMMM)/polyvinyl alcohol (PVA) shells. Morphology analysis confirmed that the microcapsules were successfully fabricated with core-shell structure and global shape. The microcapsules dispersed homogeneously in epoxy coating with an appropriate ratio of around 3.0–4.0 wt%. No interface debonding appeared between epoxy and microcapsules. Microcapsules had excellent thermal stability and resisted violent repetitive temperature changes without rupture. Chemical analysis of the shell confirmed the existence of gel PVA in pores of the cross-linked HMMM framework structure. Because the core materials penetrated shells through pores, it caused the increase in surface hydrophobicity of coatings. The release capability of the core material was enhanced by increasing the PVA content in shells and higher content of microcapsules in coatings. However, the excessive addition of microcapsules reduced the wear resistance of the epoxy coating. According to the ice shearing force test results, only 1.0 wt% addition of PVA/HMMM microcapsules significantly improved the de-icing performance of epoxy coating even under temperatures of − 20 °C. The reason was that the released oily molecules could dramatically reduce the adhesion between ice and epoxy.