Development of mesoporous silica-based active coatings for methylmercury removal: Towards enhanced active packaging

Journal article, 2025

Active coatings capable of selectively removing pollutants are an innovative approach against human exposure to pollutants via food. This study aimed to develop an active coating capable of removing methylmercury from liquid food media. Thiolation of mesoporous silica particles modified via (3-Mercaptopropyl)trimethoxysilane increased their mercury adsorption capacity to 100 mg/g. The particles were successfully integrated into industrial, epoxy and polyurethane coatings but the induced mercury adsorption efficiency in the coatings was dependent on their type of binder. Scanning electron microscopy and energy-dispersive X-ray results revealed that the silica particles were entrapped within the coatings but remained more accessible to the external media in the industrial and polyurethane coatings. Thermogravimetric analysis confirmed the successful integration of the components. The kinetics of adsorption showed that the adsorption of methylmercury was achieved within a time range of 20-240 min, depending on the binder used in the coating. The methylmercury adsorption ability of the coatings was preserved in different food simulants and in the presence of competitive ions and in an environment comprising cysteine. In vitro biosafety assays on different cell lines showed no negative effect from the silica modification on the safety of the coatings.