Durable and room-temperature curable superhydrophobic composite coating on nitrocellulose lacquer

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 degrees C. The groups of Si-O-Si 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 degrees with slide angle of 2 degrees and is still >150 degrees 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 crosscut 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 degrees. 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. (C) 2017 Elsevier B.V. All rights reserved.