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/cm 2 , 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 20 mJ·m -2 . SiEP-MM@HMSNs has a strong inhibitory effect on bacteria and algae, reaching over 90%. 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. Molecular design of antifouling coatings. • MM@HMSNs can slow down the rapid release of antifoulant medetomidine (MM). • The modification of epoxy resin (EP) by PDMS improves the toughness of coating. • The coating SiEP-MM@HMSNs has excellent marine antifouling performance. • SiEP-MM@HMSNs can maintain good antifouling performance for four months.