Ar/HMDS Plasma Jet as a Tool for Superhydrophobic Coatings on Epoxy Resin

During actual operation, the superhydrophobic surface provides excellent resistance to condensation and icing due to its low wettability. This study used an Ar/HMDS mixture as the working gas and a low-temperature plasma jet induced in an atmospheric pressure environment to create a superhydrophobic coating with a water contact angle of up to 172.6°, utilized a typical epoxy resin plate as the substrate. XPS analysis indicated the presence of a significant number of low surface energy functional groups containing Si and O on the epoxy resin surface. Scanning electron microscope (SEM) revealed the presence of dense microstructure and nanostructure on the surface. The process of plasma jet water-repellent modification of epoxy resin surface was further analyzed from two perspectives: particle collision in the electric field, molecular bond breaking and reorganization reaction of monomer, and grafting reaction of free radicals formed on the surface of epoxy resin by high-energy jet bombardment, combined with XPS test of high-purity discharge products in the jet tube. The results indicate that the epoxy resin surface modified by plasma jets achieves superhydrophobicity. The modification time is extended to 180 s, and the static water contact angle is increased from 72.4° to 172.6°. Dense microparticle and nanoparticle are formed on the surface. For the secondary binary composite rough structure, the percentage of Si and O elements increased to 41.3% and 27.8%, respectively. The Si(CH
₃
)O
_3/2
system contributed the most, accounting for 40.5%.