We report novel approaches to fabricate superhydrophobic and superhyrophilic functional coatings showing self-healing properties. The preparation of superhydrophobic coatings is based on the “syneresis” of reactive organosilanes, and their subsequent hydrolysis/polycondensation reactions with moisture in the air . They exhibited excellent self-healing properties against long-term irradiation of 172 nm vacuum UV (VUV) light/plasma, or mechanical damages. The oxidized/damaged surfaces could be healed after heating or leaving samples in air, for 30 min to several hours, leading to the regeneration of superhydrophobicity. Our superhyrophilic coatings were prepared by using a mixture of positively-charged nano-scale clay platelets and the partially-charged polymer, polyvinylpyrrolidone (PVP) as precursors . They kept their superhyrophilicity more than 6 months and allowed the re-formation of bonds when exposed to humid air, resulting in self-healing of damage up to ~20 μm across. Our functional coatings undoubtedly show great potential for applications in a variety of engineering fields.
1. C. Urata, G. Dunderdale, M. England and A. Hozumi, J. Mater. Chem. A, 3, 12626-12630 (2015).
2. M. W. England, C. Urata, G. J. Dunderdale, A. Hozumi, ACS Appl. Mater. Interfaces 8, 4318−4322 (2016).