High-pressure induced acceleration pathways for water diffusion in heavy duty anticorrosion coatings under deep ocean environment: (II) Shape optimization and surface modification of the fillers

Regarding the adverse “reverse maze” effect of lamellar fillers to durability of coatings in deep-sea environments, the surface modified spherical hollow glass microspheres were used as fillers to prepare heavy-duty anti-corrosion coatings. The coatings were investigated under simulated deep-sea environments of 14.0 and 20.0 MPa. The results demonstrate that the curved interface of spherical fillers significantly reduces residual solvents and gases within the coatings and inhibits stress concentration at filler edges. The surface modification effectively enhances the interfacial bonding strength and compatibility between the glass microspheres and the coatings, thereby notably prolonging the service life of the coatings in harsh abyssal environments. These findings confirm the validity of the deep-sea coating failure mechanism postulated in our previous research and may provide critical design guidelines for deep-sea coatings.