Protection of zinc from corrosion by coverage with a hydrated cerium(III) oxide layer and ultrathin polymer films of a carboxylate self-assembled monolayer modified with alkyltriethoxysilanes

Abstract Ultrathin films of one- and two-dimensional polymers were prepared on a zinc electrode coated with a hydrated cerium(III) oxide Ce2O3 layer by modification of a 16-hydroxyhexadecanoate ion HO ( CH 2 ) 15 CO 2 - ( HOC 16 A - ) self-assembled monolayer (SAM) with alkyltriethoxysilanes. The protective efficiency, P of the film was determined by polarization measurements of the electrodes bare and covered with the polymer films in an oxygenated 0.5 M NaCl solution. The respective P values for the one-dimensional polymers of the HOC16A− SAM modified with octyltriethoxysilane C8H17Si(OC2H5)3 (C8TES) and octadecyltriethoxysilane C18H37Si(OC2H5)3 (C18TES) were 94.4 and 95.1%. The values for the two-dimensional polymers of the HOC16A− SAM modified with 1,2-bis(triethoxysilyl)ethane (C2H5)3Si(CH2)2Si(C2H5)3 plus C8TES and C18TES were 95.4 and 96.5%, respectively, indicating higher than those of the one-dimensional polymers. Structures of the polymer films were characterized by contact angle measurement with a drop of water and X-ray photoelectron and FTIR reflection spectroscopies.