Robust and repairable PET superwicking surfaces: A simple two-step fabrication approach for enhanced liquid transport

Abstract

Superwicking surfaces stand out for their superior wicking abilities that expedite liquid flow across their structural form. The surface has attracted significant attention due to its promising applications in water harvesting, thermal management, biomedical fields, and more. However, minimizing manufacturing costs while ensuring long-term stability remains a challenge in the production of superwicking surfaces and enhancing their applications. This study presents the development of polyethylene terephthalate (PET) superwicking surfaces using a straightforward two-step technique with sandpaper abrasion and nanocomposite coating of TiO2-SiO2. Superwicking performance was evaluated through droplet spread analysis, contact angle measurements, and water drying tests. Results exhibited a more than 100% rise in absorbed water film thickness on the 180-grit abraded superwicking surface versus the coating on raw PET. Additionally, a 10μl droplet displayed more than triple the spreading diameter. Sandpaper abrasion, high-pressure water impact, and outdoor stability tests appraised surface durability. The PET superwicking surface showed enhanced mechanical durability and outdoor stability, attributed to protective microgrooves and photocatalytic self-cleaning capacity. The findings of this study clearly address the high cost, instability, and extreme lack of durability associated with conventional superwicking surface preparation. More importantly, the developed self-repairing capability of the surface allows it to be restored by reapplying the spray coating after the nanoparticles have been worn away due to heavy use. This advancement will significantly promote the use of such surfaces in heat transfer and self-cleaning applications.