Preparation of Durable Superomniphobic Surfaces for Applications in Condensation Heat Transfer

Super-liquid repellency properties usually play a very important role in many fields, such as, in atmospheric water harvesting, using superomniphobic surfaces (SOSs) can enhance the condensation heat transfer. However, the weak durability of SOS was an obstacle to practical applications. In this study, durable SOSs were prepared through adhesive effect. During the preparation process, adhesive was used as a middle connecting layer to enhance the connection between coating materials and substrates. Long-chain fluorocarbons were used to decrease the coating's surface energy. Through surface geometry and wettability tests, "cauliflower-like" structures were formed and the superomniphobicity property was obtained. The obtained SOS possessed a high static contact angle above 150 degrees and a low sliding angle below 10 degrees for liquid droplets, such as ethanol liquids. The durability was evaluated via a sandpaper abrasion method and a tape peeling test. The SOSs could withstand sandpaper abrasion for 35 cycles and tape peeling (6.24 kPa applied pressure) for 8 cycles while maintaining its superomniphobicity. These durable SOSs are believed to offer potential applications in condensation heat transfer.