A jump in corrosion protection performance of low concentration silane conversion film achieved by NaClO activation

This study introduces an efficient method to enhance the corrosion resistance of copper using a low-concentration silane conversion film activated by sodium hypochlorite. The native chemical passivity of copper surfaces hinders effective bonding with 3-aminopropyltriethoxysilane, limiting protective performance even at high concentrations. The incorporation of NaClO into the silane solution promotes micro-etching, generating active Cu + /Cu 2+ ions that facilitate strong coordination with APTES via Cu–N and Si–O–Cu bonds. Electrochemical tests revealed a corrosion inhibition efficiency of 98.63 %—nearly 50 % higher than pure APTES films—while structural analyses confirmed denser, hydrophobic layers. This strategy significantly improves economic efficiency and broadens the application potential of silane-based coatings on copper.