Nanoscale chemical heterogeneity enables the co-existence of opposing superhydrophobic and hygroscopic properties

Superhydrophobicity and hygroscopicity are two properties that are theoretically exclusive to each other. The fabrication of functional fabrics with these two properties remains very challenging. In this work, it is demonstrated that a non-sticky superhydrophobic and hygroscopic fabric coating can be prepared via the photo polymerization of hexadecyl acrylate and methacrylic acid. On coating surface , the phase-separation-induced chemical heterogeneity has a unique feature of possessing elevated continuous hydrophobic domain and depressed hydrophilic domain, as evidenced by atomic force microscopy measurement. The elevation of hydrophobic domain (i.e., depression of hydrophilic domain) allows the hydrophilic domain to make negligible contribution to the surface wettability to water drop, but can absorb water molecules, thus inducing the unique superhydrophobic but hygroscopic property. The coating has a very low total surface energy of 22.61 mN m −1 , with its polar part (0.01 mN m −1 ) being negligible, thereby showing a high static water contact angle of ~112° on flat glass slide. The coated polyester fabric shows a non-sticky superhydrophobicity with a static water contact angle of ~151° and a water shedding angle of ~10°, as well as good hygroscopic and anti-static properties. We anticipate that this novel coating and the reported strategy of generating the particular chemical heterogeneity may lead to the development of advanced special wettability coatings for various applications.