Technical note: Correlation between protection of steel from corrosion and the conductivity of n-semiconductor pigments

Pigments such as aluminum oxide (Al2O3), zinc oxide (ZnO), and iron oxide (Fe3O4) that were specially prepared to have pronounced n-semiconductive properties were tested in commercial polymer vehicles (epoxy resin [ER]) and anticorrosive paints (chlorinated rubber [CR] or coal tar epoxy [CTE]) on steel. Three types of commercial titanium oxide (TiO2), used only as white coloring agents, also were tested. The specially prepared n-semiconductors satisfactorily protected the steel following their n-semiconductivity, as did the TiO2 (less protection). The semiconductivity of the TiO2 was acquired by chance during preparation.