Preparation and evaluation of a fluorinated nano-silica superhydrophobic coating for cement pavement

Abstract

To reduce the traffic risk of pavement icing, a fluorinated nano-silica superhydrophobic coating for cement pavement was prepared with fluorinated nano-silica, carbon black, and waterborne epoxy resin. The component and spraying dosage were analyzed for optimal performance by combining the fluorination verification, component contents determination, and spraying dosage optimization. The engineering performance was evaluated for applicability, basing anti-icing performance and pavement durability. The test results showed that the fluorine group has successfully drafted on the nano-silica. The determined content of nano-silica is 75 wt% and of carbon black is 17.5 wt% of waterborne epoxy resin. The optimal application amount is 0.5 L/m2 to balance the requirement of superhydrophobic property and skid resistance. Meanwhile, the prepared coating has a good engineering performance. It can boost 70 % ability to repulse incoming water droplets, delay 40 % time of ice formation, and increase 40 % ratio of ice-layer removal compared with the uncoated. It can also maintain the basic appearance and superhydrophobic property after about 150,000 times wheel abrasion or three high-low temperature cycles. This demonstrates that the prepared coating has a good potential for practical use.