Langmuir–Blodgett films of dococyltriethylammonium bromide and octadecanol on iron. Deposition and corrosion inhibitor performance in CO2 containing brine

The stability and compressibility of Langmuir films of dococyltriethylammonium bromide (C22TAB) and 1-octadecanol (C18OH) and their mixtures on water surfaces were first investigated. Langmuir–Blodgett films were transferred onto iron substrate. Their effect on corrosion of iron in carbon dioxide containing brine were investigated by electrochemical methods. The C18OH formed a thin homogenous film with molecular area 19.4 Å2 at 36 mN m−1 at water surface. The films of C22TAB and C22TAB/C18OH mixtures were less dense, with 31 Å2 molecular area at 36 mN m−1 at water surface. The corrosion rate of iron substrate was reduced by 95% by deposition film of C18OH, while the corrosion rate of iron was reduced by 60% for films of C22TAB and C22TAB/C18OH mixtures.