Corrosion Inhibition of Iron in Acidic Solutions by Monoalkyl Phosphate Esters with Different Chain Lengths

Abstract

The inhibition effect of three amphiphilic monoalkyl phosphate esters with different chain lengths, mono-n-butyl phosphate ester (BP), mono-n-hexyl phosphate ester (HP) and mono-n-octyl phosphate ester (OP), on the corrosion of iron in 0.5 M H 2 SO 4 solutions was investigated by using electrochemical impedance spectroscopy (EIS) and polarization curve methods. The electrochemical results indicate that, BP, HP and OP all acted as mixed type corrosion inhibitors with dominant cathodic effect. BP shows the lowest inhibition efficiency as compared to HP or OP. However, the inhibition efficiency of HP is almost the same with that of OP under similar conditions since the molecular aggregation state at the iron / solution interface plays a more important role. X-ray photoelectron spectroscopic (XPS) characterization demonstrates that three alkyl phosphate esters adsorbed on the iron surface through the unionized P-OH groups. The adsorption of BP, HP and OP fitted well with the Langmuir model.

In situ synthesis of one eco‐friendly polyacrylic acid/zinc colloidal particles doped polyacrylic acid as an efficient corrosion inhibitor for iron

“…The equivalent circuits used for fitting the EIS data shown in Figures and are presented in Figure . We can reasonably assume that the corrosion reaction only occurred at the sites that were not covered by inhibitor molecules . When inhibitor was added into NaCl solution, the inhibitor could create a barrier effect against the attack of corrosive species due to the strong adsorptive action between the functional group and iron surface.…”

“…The working electrode was prepared by a 2 mm‐diameter iron rod (Alfa Aesar, 99.995%), and the preparation method of the working electrode was described in our previous work . First, the iron rod was soldered with one copper wire, and embedded in an epoxy resin mold, leaving only its cross section exposed to the corrosive solution; second, the liquid epoxy resin was mixed with the triethylenetetramine in a weight ratio of ∼10:1 to form a uniform liquid phase, and then the resulting liquid was poured into the mold, followed by the curing of epoxy resin in an oven at 25°C for 24 hr.…”

CORROSION INHIBITION OF 1,4-DIMETHYL PHENYL-N,N-DIMETHYLANILINIUM DIBROMIDE SALT ON MILD STEEL IN HCl SOLUTION

“…Organic nitrogen-containing compounds as corrosion inhibitors for different metals were studied widely by many authors [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Sulphurcontaining inhibitors [19][20][21][22][23][24][25][26] and phosphorus organic inhibitors were investigated by other authors [27][28][29][30]. The effect of structure on the inhibition of some organic compounds was also studied [30,31].…”

“…Sulphurcontaining inhibitors [19][20][21][22][23][24][25][26] and phosphorus organic inhibitors were investigated by other authors [27][28][29][30]. The effect of structure on the inhibition of some organic compounds was also studied [30,31].…”

A study on the differences in morphology and corrosion resistance performance between two different bis(2-ethylhexyl) phosphate self-assembled thin films prepared on an iron substrate in water and ethanol solvents

“…19,[33][34][35][36][37] The middle peak centered at 531.6 eV is the minimal component and mainly originates from the OH À of hydroxide such as FeO(OH) and the O-P bond in phosphate group. For BEP E SAMs, the lowest peak is located at binding energy of 529.6 eV which is assigned to oxygen atoms bonded to ferric oxides such as Fe 2 O 3 and Fe 3 O 4 , 19,33-37 and the highest peak is located at binding energy of 533.0 eV which is corresponding to the existence of oxygen in the chemisorbed H 2 O.…”