Boosting the acid penetration barrier of epoxy-silica organic-inorganic hybrid coating via adjusting its molecular structures: Experimental and molecular dynamics simulation study

Abstract

The permeability barrier property of coatings against corrosive media determines their service life. Herein, the molecular structure of epoxy-silica organic-inorganic hybrid (OIH) coating is regulated to endow the coatings with enhanced barrier properties by a simple sol-gel method. Experiments show that the coating with 8% Si-O-Si structure has the best acid penetration resistance after 45 days of immersion in 10 wt.% H2SO4 solution. In addition, molecular dynamics simulation results show that the molecular structure of OIH affects the densification of the coating, forming a highly cross-linked network structure that inhibits the diffusion and destructive effects of corrosive media and thus affects the acid penetration resistance of the coating.