On the acid-responsive release of benzotriazole from engineered mesoporous silica nanoparticles for corrosion protection of metal surfaces

Corrosion inhibitors are largely exploited for the development of highly performing polymeric active coatings. One of the major drawbacks, however, relies in their UV sensitivity, which may compromise their ability to effectively prevent corrosion processes. This issue is particularly relevant in the field of cultural heritage preservation, in which polymeric active coating which are able to ensure a reliable and long-lasting protection against corrosion are highly needed. Besides proving that UV-induced photodegradation impressively lowers the corrosion inhibition ability of benzotriazole (BTA), in the present work we show that this phenomenon can be largely prevented by exploiting inorganic nanocarriers. More specifically, BTA molecules loaded into functionalized mesoporous silica nanoparticles are preserved from photodegradation and released in the host coating only in the presence of acid-related external stimuli. Accelerated corrosion tests carried out on a commercial acrylic-based coating containing engineered mesoporous silica nanoparticles loaded with BTA demonstrated that the developed system possesses an excellent anticorrosion ability.