Development of Sustainable Hydrophobic Coatings for Textiles Based on Sputtered Copper Nitride

Abstract This study investigates the use of copper nitride (Cu 3 N) thin films as a hydrophobic coating for acrylic textiles, offering a safer and more sustainable alternative to conventional fluorocarbon-based treatments. Copper nitride is a non-toxic, abundant, and cost-effective semiconductor material with tunable properties, yet its application in textiles remains largely unexplored. In this work, Cu 3 N coatings were deposited on acrylic fabric using reactive sputtering at room temperature, 50W of power and 3.5 Pa of working pressure, under two different gas atmospheres: pure nitrogen (N 2 ) and a nitrogen-argon (N 2 + Ar) mixture. Deposition times were varied at 60, 90, and 120 min to evaluate the influence of process duration on hydrophobic performance. Hydrophobicity was assessed by measuring the water contact angle on coated samples, both in their initial state and after mechanical stress tests including washing and folding. The results demonstrated strong hydrophobic behavior across all samples, with contact angles ranging from 96.30° to 113.68°. Notably, coatings deposited under N 2 + Ar showed slightly enhanced performance and durability compared to those deposited under pure N₂. The entire process was conducted at room temperature and generated no chemical waste, highlighting its environmental advantages. These findings suggest that copper nitride coatings can effectively impart hydrophobicity to textiles without relying on harmful fluorinated compounds. The combination of performance, safety, and sustainability positions Cu 3 N as a promising candidate for future textile finishing technologies.