Nanodiamond Modification of Kevlar Fabric to Enhance Surface Activity and Eliminate PFAS

Aramid fibers such as Kevlar are frequently used in protective applications due to their mechanical strength and thermal stability. However, the low surface reactivity of aramid has limited its functional modifications, particularly for enhancing water resistance, an increasingly important requirement in protective textiles. This study presents a surface functionalization approach that imparts durable hydrophobicity to Kevlar fabric. Polyacrylic acid (PAA) was used as a coupling agent to improve the adhesion of nanodiamonds (ND), including detonation (DND) and hydroxylated forms (ND‐OH), to the fiber surface. Subsequent treatment with n‐dodecyl tri‐methoxy silane generated a robust hydrophobic finish. The PAA‐DND‐silane system exhibited the highest water contact angle and retained its performance after repeated washing and abrasion cycles. The enhancement in hydrophobicity was attributed to nanostructured roughness promoting a Cassie‐Baxter wetting regime. Crucially, the modification did not compromise the fabric's flexibility, although it reduced the air permeability 50%. This scalable strategy offers a pathway to multifunctional aramid textiles that meet the stringent demands of modern protective gear.