Additional modification to two-dimensional polymer films of a hydroxymethylbenzene self-assembled monolayer with alkyltriethoxysilanes for enhancing the protective abilities against iron corrosion

Abstract

Additional modification of the ultrathin two-dimensional polymer film, a p-hydroxymethylbenzene C 6H 4CH 2OH self-assembled monolayer modified with 1,2-bis(triethoxysilyl)ethane (C 2H 5O) 3Si(CH 2) 2Si(OC 2H 5) 3 (BTESE) and alkyltriethoxysilane C n H 2 n+1 Si(OC 2H 5) 3 (C n TES, n = 8 or 18), was attempted to improve the protective ability of the film against iron corrosion. The ability of the film was examined by polarization measurement of an iron electrode coated with the film in an oxygenated 0.5 M NaCl solution after immersion in the solution for 1.5 to 72 h. Marked improvement of the protective efficiency, P was not obtained by additional modification to the polymer film with BTESE. The P values of the two-dimensional polymer films were markedly increased by additional modification with C 8TES. The increases in P were ascribable to improvement of alkyl tail arrangement and additional interconnection in the polymer films. The film on the iron surface was characterized by contact angle measurement, FTIR reflection spectroscopy and X-ray photoelectron spectroscopy. The protective abilities of the two-dimensional polymer films additionally modified with C 8TES were persistent during immersion for 72 h.