Superhydrophobic Coating Deposited on Foamed Concrete with Super‐Robust Mechanical and Self‐Repairing Properties

Abstract

A super‐robust and self‐repairing superhydrophobic (SRS) coating is prepared on foamed concrete via a facile and low‐cost method using hydrophobic silica nanoparticles as building blocks connected by silicone sealant and epoxy resin for constructing micro‐/nanostructures. The surface wettability, morphology, and chemical composition are tested by a contact angle (CA) goniometer, scanning electron microscope, and Fourier‐transform infrared spectrometer, respectively. All the as‐prepared SRS coatings exhibit satisfied superhydrophobicity with the hydrostatic CA of about 160° and the sliding angle (SA) of about 1.7°. The results show that the SRS coating has good self‐repairing performance. For testing its mechanical stability, the superhydrophobic foam concrete is tested by 200 g (2.83 kPa) weight, sanded by 800 mesh sandpaper, which can be worn for 150 cycles (21 m), better than the reported mechanical performance. In addition, the superhydrophobicity can recover by heating at 100 °C for half an hour. The preparation method of the coating is simple, low cost, and excellent in mechanical performance, which provides the possibility for large‐scale industrial applications in the construction field.