Loading of aerogels in self-healable polyurea foam to prepare superhydrophobic tough coating with ultra-long freezing delay time and high durability

It is still a big challenge to prepare anti-icing surfaces combining long freezing delay time and high durability. In this work, we proposed an aerogel-incorporated foam architecture, which was found to drastically improve anti-icing performance and durability. In detail, we developed a self-healable polyurea foam coating via incorporating dynamic cross-linking, enhancing the mechanical strength and controlling foam-forming process. The polyurea foam with porosity of and pore size of enabled the room-temperature self-healing within 24 h, while preserving high adhesion strength of 12 MPa. Subsequently, silica aerogel was successfully introduced into the foam pores by utilizing the emulsion polymerization . As-generated hierarchical porous structure was found to increase freezing delay time from 600 s to 18000s at -10 °C owing to the appreciably reduced thermal conductivity and the increase of the pore pressure. Meanwhile, the self-healing ability and hierarchical porous structure ensures the high durability. The coating could maintain its superhydrophobicity and anti-icing performance under water flow impacting at 10 kPa pressure, repeat bending under 180°, and acid/alkaline attack. The performance was greatly advantageous over the superhydrophobic coatings without the foam structure.