Marine antifouling coating with dual antifouling mechanism based on medetomidine

Marine fouling has seriously hindered the development of the marine economy. Antifouling coating is an effective protective method. Here, a composite coating (SiEP-MM@HMSNs) was developed, characterized by the dual antifouling mechanism. The nanoparticles (MM@HMSNs) were prepared by loading the synthetic medetomidine (MM) in hollow mesoporous silica (HMSNs) to achieve the static antifouling method by resealing. Organosilicon modified epoxy resin (SiEP) enhances hydrophobicity, as a dynamic antifouling method. Due to the porous mesoporous structure, MM@HMSNs with the stable particle size (about 200 nm) achieves an extremely high loaded capacity (about 20%). It can achieve continuous and stable release to get a release rate of 1.71 μg/cm², when dispersed in the coating. SiEP has a significant improvement in hydrophobicity compared to epoxy resin (EP), with a water contact angle of 100° and surface free energy of 18.09 mJ/m². SiEP-MM@HMSNs has a strong inhibitory effect on bacteria and algae, reaching over 90%. Meanwhile, SiEP-MM@HMSNs has maintained its antifouling performance after 4 months of marine field tests. This study provides a possible method for designing antifouling coatings using the dual antifouling mechanism.