Fiber surface-immobilized alkane chain aggregates via alkyl bis(diaryl)carbenes crosslinking for superhydrophobicity and moisture/air permeability of textiles

Superhydrophobic textiles attract significant interest for diverse applications. However, silane coupling agents and polydimethylsiloxane utilized in hydrophobic textiles exhibit limited applicability, poor hand feel, inadequate moisture and air permeability, along with environmental and health concerns. To broaden the applicability and enhance the safety of hydrophobic agents, this work synthesizes Alkyl bis(diaryl)diazomethanes. Upon thermal activation, the bis(diaryl)diazene groups generate highly reactive carbene intermediates that react with X-H bonds (X = C, O, N) in cotton, polymer and silk fibers to form stable C-X bonds (X = C, O, N), resulting in a hydrophobic coating on the fiber surface. Concurrently, the dual-carbene design increases reactive sites on the fiber surface, enhancing binding affinity. The introduction of long-chain alkyl groups replaces fluorine-containing and silicon-containing groups to reduce the fiber surface energy. Furthermore, Alkyl bis(diaryl)diazomethane is observed to undergo agglomeration during processing and self-crosslink into nanostructures on the fiber surface, consequently enhancing the roughness of the hydrophobic coatings on the fiber surface. The modified fabrics exhibited water contact angles (WCA) >150° and sliding angles (SA) <10°, confirming superhydrophobic. While retaining the original hand feel, moisture and air permeability, the modified fabrics exhibited exceptional soap washing fastness, rubbing resistance, chemical stability, superior anti-fouling properties, and self-cleaning functionality, along with enhanced mechanical properties. This modification strategy exhibits substantial market potential in the hydrophobic textiles sector.