Room-temperature curable superhydrophobic composite coating (SHC) was fabricated on nitrocellulose lacquer using single-step spraying process. The suspension of perfluorosilane-coated silica nanoparticles was synthesized by sol-gel method at 60 °C. The groups of SiOSi and CF2 are detected on the SHC by XPS and FTIR. The SEM and AFM images exhibit rough and hill-like morphology of the SHC. The contact angle on the SHC for deionized water reaches 161° with slide angle of 2°, and is still > 150° even for acidic and alkaline liquid. Cross-cut tape adhesion test manifests that adhesion force of superhydrophobic coating to nitrocellulose lacquer is a highest class of 5B according to ASTM D3359 standard. Furthermore, the SHC still keeps good superhydrophobicity by cross-cut tape adhesion test and exposure to outdoors for 300 days. After immersing in acid and alkali for 3 h or organic solvents for one week, water contact angle of SHC is still > 140°. The SHC with sufficient adhesion to various materials has excellent durability and chemical stability, prolonging service life of nitrocellulose lacquer via maintaining their self-characteristics.
Available online 26 August 2017