Preparation of all-organic superhydrophobic PTFE/epoxy composite coatings

Abstract

Superhydrophobic coatings with micro-nano hierarchical structure constructed by nano particles usually have a poor behavior in water impact situation. This weakness limits superhydrophobic coatings' outdoor potential applications. A low-acoustic resistance all-organic superhydrophobic coating was prepared by spraying and compression molding methods with epoxy and PTFE particles. Water impact test was designed according to impact failure mechanism, and then water impact resistance was evaluated and compared with commercial superhydrophobic coatings'. The results indicate that the hydrophobicity reaches peak when coating contains 70% (mass fraction, the same below) PTFE particles, with 164.13° water contact angle(WCA) and 3° water slide angle(WSA). For water impact resistance, the coating with 75% PTFE particles has the best performance, it can keep the WCA at 154.62° after 22.77 ms-1 water jet impact test. And the molding coatings have better performance than sprayings. Besides, the results also show coating's good adhesion and wearability, for example, it can keep the WCA at 150.51° and WSA at 4° after 25-cycle tape peeling test, and keep the WCA at 149.21° and WSA at 9° after 20-cycle wear test.

Keywords

• superhydrophobic coating
• ptfe
• epoxy
• spraying
• compression molding
• water impact resi-stance