Robust, conformal Cu₂O coatings on polypropylene fabrics via atmospheric-pressure spatial atomic layer deposition

Copper-based nanocoatings offer significant potential for advanced functional textiles due to their broad-spectrum antimicrobial properties. For the first time, this study demonstrates atmospheric-pressure spatial atomic layer deposition (AP-SALD) as a scalable method for depositing uniform cuprous oxide (Cu₂O) coatings on a porous textile substrate. The AP-SALD process enables conformal, nanoscale coating of spun-bond polypropylene fabrics - commonly used in N95 respirators - at polymer-compatible temperatures (100-120 °C), eliminating the need for vacuum systems. Structural and morphological characterization confirms the formation of continuous Cu₂O films with growth rates of ∼0.06 nm per cycle, confirmed via in situ optical monitoring. The coatings exhibit excellent mechanical durability under abrasion, washing, and flexing, with no significant damage or delamination. The fabric's filtration performance remains unaffected after coating and coatings deposited at 100 °C and 120 °C demonstrate low cytotoxicity in biocompatibility assays, supporting their suitability for skin-contact applications. Together, these results establish AP-SALD as a practical, industrially scalable, and high-throughput route for producing durable and safe functional textiles, with direct relevance to healthcare and personal protective equipment.