Bio‐/Environment‐Friendly Cationic Gemini Surfactant as Novel Corrosion Inhibitor for Mild Steel in 1 M HCl Solution

Abstract

Bio-/environment-friendly cationic gemini surfactant, ethane-1,2-diyl bis(N,N-dimethyl-N-hexadecylammoniumacetoxy)dichloride, referred to as 16-E2-16, was synthesized and characterized. Corrosion inhibition effects of 16-E2-16 on mild steel (MS) surface in 1 M HCl solution at 30, 40, 50 and 60°C were evaluated using gravimetric analysis, potentiodynamic polarisation and electrochemical impedance spectroscopy measurements. The nature of the protective inhibitor film formed on the MS surface was analysed by SEM, EDAX and FT-IR, while TGA was used to assure the thermal behaviour and stability of the film at high temperature. The formation of [inhibitor-Fe 2? ] on the surface of MS was confirmed by UV-visible spectroscopy. The inhibition efficiency of the studied inhibitor increased with increasing concentration and solution temperature. The compound behaved as a mixed type inhibitor and acted by blocking the electrode surface by means of adsorption obeying the Langmuir adsorption isotherm. Surface active properties and corrosion inhibition effects of 16-E2-16 in the presence of inorganic (NaI) and organic (NaSal) salts were also investigated and are discussed. Density functional theory calculations have been carried out to correlate the efficiency of the compound with its intrinsic molecular parameters.

Development, Characterization and Electromechanical Actuation Behavior of Ionic Polymer Metal Composite Actuator based on Sulfonated Poly(1,4-phenylene ether-ether-sulfone)/Carbon Nanotubes

“…The chosen equivalent circuit for SPEES based IPMC membrane composed of solution resistance (R s ) and constant phase elements (CPE) and charge transfer resistance (R ct ). CPE a non-ideal capacitor substituted for double layer capacitance (C dl ) and its impedance can be calculated according to equation (3) 53,54 .where Y o is the amplitude comparable to the CPE and n is the CPE exponent (shows the roughness of the electrode with values varies from 0 to 1). An ideal capacitor shows n = 1, while n = 0 shows resistor, n = −1, then CPE resembles an inductor and for n = 0.5 the Warburg diffusion behavior 54,55 , j is the square root of −1 (imaginary number) and ω represent angular frequency in Radius −1 .…”

Organic Corrosion Inhibitors

“…The gemini alkylammonium salts possess a very low critical micelle concentrations (cmc), which is up to hundred times lower than cmc's of corresponding monomeric surfactants. Gemini surfactants also have a larger molecular area in comparison to monomeric analogs which cause them to act more efficiently as corrosion inhibitors [80,[101][102][103][104][105][106][107][108][109][110]. Dimeric surfactant 1,4-tetramethylene-bis(N-dodecyl-N,N-dimethylammonium bromide) (12-4-12) is more efficient in decreasing corrosion rate of carbon steel in 1 M HCl than its monomeric analogue N-dodecyl-N,N,N-trimethylammonium bromide (DTAB).…”

Efficiency of cationic gemini surfactants with 3-azamethylpentamethylene spacer as corrosion inhibitors for stainless steel in hydrochloric acid

“…Chemisorption is connected with donor-acceptor interactions [28]. Adsorption is favourable due to the presence of electron-rich structures such us heteroatoms with unbonded electrons (N, O, S, P) [29,30] and π electrons (benzene rings, multiple bonds) [22,24] as these can share electrons with the free d-orbitals of metals [27].…”

“…Corrosion in acidic environments is a serious problem in petrochemical, marine or chemical production [37,38] due to the use of hydrochloric acid solutions [29] for cleaning, pickling, descaling or oil well acidification [26,39]. Every year corrosion results in huge economic losses, decreasing operation efficiency and increasing the risk of accidents [40].…”

“…equilibrium constant (K ads ) [22] and this parameter was used to determine the Gibbs free energy (ΔG ads ) based upon equation (9) [29,30]:…”