Application of hollow mesoporous organosilica nanoparticles as pH and redox double stimuli-responsive nanocontainer in the controlled release of corrosion inhibitor molecules

The stimuli-responsive release could reduce the waste of the corrosion inhibitor and realize the accurate repair of corroded region. In this work, hollow mesoporous organosilica nanoparticles (HMON) were first synthesized by silica-etching chemistry tailoring method. Then, HMON were encapsulated with 2-mercaptobenzothiazole (MBT) corrosion inhibitor molecules to build an intelligent corrosion inhibitor system, i.e., MBT@HMON. The microstructure and frame composition of the synthesized HMON were characterized. After the successful encapsulation of MBT into HMON, the release kinetics of MBT from HMON under different dithiothreitol (DTT) concentration and pH conditions were investigated. Finally, the corrosion inhibition performance of MBT@HMON for copper alloy was evaluated in 3.5 wt% NaCl solution by weight loss test and electrochemical impedance spectroscopy (EIS). The results show that the controlled release of corrosion inhibitor MBT from HMON could be realized by tuning the redox and pH conditions of corrosion medium. When the appropriate concentration of MBT@HMON was added into the corrosion medium (1.6 g·L −1 in this work), the corrosion of cooper alloy was greatly inhibited. This simple and general strategy of introducing corrosion inhibitors loaded HMON directly into the corrosion medium offers a new prospect for the application of nanocontainers in the intelligent corrosion protection of metallic materials.