Preparation of superhydrophobic photothermal coatings via sequentially grown mesoporous silica-coated CNTs for anti-icing applications on cement concrete

Delaying ice formation and reducing ice adhesion on concrete surfaces have broad application prospects in civil engineering. Superhydrophobic coatings can effectively delay freezing, which, however, are very likely to fail after multiple freeze-thaw cycles. This study proposed a simple method for preparing superhydrophobic photothermal coatings using carbon nanotubes (CNTs). Combining stencil and sol-gel methods, superhydrophobic mesoporous silica-coated CNTs (SMC) were fabricated by growing and modifying mesoporous silica on CNTs. The SMC particles were then mixed with epoxy resin and sprayed onto cement concrete surfaces. The optimal EP/C ratio of 1:4 yielded a coating with a contact angle of 158.5°, which exhibited excellent mechanical durability and stability. The coating exhibited dual functionality by significantly prolonging ice condensation time and enabling effective photothermal-induced melting of frozen droplets. Furthermore, the coating demonstrated exceptional performance in ice removal applications, substantially reducing the force required to detach ice formations from treated surfaces. Additionally, the EP/C-4 coating formed a protective layer on the surface of the concrete, reducing water absorption and improving the resistance to freeze-thaw cycles.