Large-Area Deposition of Hydrophobic Poly(hexafluorobutyl Acrylate) Thin Films on Wetting-Sensitive and Flexible Substrates via Plasma-Enhanced Chemical Vapor Deposition

In this study, hydrophobic poly(hexafluorobutyl acrylate) (PHFBA) thin films were successfully deposited over a large area of 25 × 50 cm using plasma-enhanced chemical vapor deposition (PECVD). Key parameters, including plasma power and the distance between the plasma antenna and the substrate, were optimized to achieve the highest deposition rate while ensuring uniformity and defect-free coatings. The optimal conditions were determined as 5 W plasma power and a 9 cm antenna-substrate distance, yielding a maximum deposition rate of 11.3 nm/min. PHFBA's low fluorine content makes it a more environmentally and biologically friendly alternative compared to heavily fluorinated polymers, addressing concerns about toxicity and environmental impact. The coatings were applied to a flexible and wetting-sensitive paper towel substrate, which was successfully coated without any visible defects. The contact angle measurements confirmed the hydrophobic nature of the films, with a maximum water contact angle of 131.9° after the deposition of PHFBA. This study highlights the potential of PECVD as an efficient and scalable method for producing hydrophobic coatings, combining high-performance properties with improved environmental considerations. The results not only validate PECVD as a scalable and precise method for thin film fabrication but also open new possibilities for its use in applications requiring durable and functional surface modifications.