| The metal products suffered from atmospheric corrosion can be effectively controlled by adding volatile corrosion inhibitor (VCI) due to the the inhibitive molecules can vaporize at room temperature. Enlighenments from the continuing develop idea, the trend in the field of VCI science is oriented to develop environmentally friendly and economic VCI.A series ofβ-amino alcohols containing multi-adsorption centers, referred as 1-morpholin -4-yl-propan-2-ol (MP), 1,3-Di- morpholin-4-yl-propan-2-ol (DMP), 1-Diethylamino-propan -2-ol (EAP), 1,3-Bis-diethylamino-propan-2-ol (DEAP), 1,3-Bis-dipropylamin o-propan-2-ol (DPAP) and 1,3-Bis-dibutylamino-propan-2-ol (DBAP) have been synthesized by alkylation reaction. The inhibition mechanism ofβ-amino alcohol inhibitors on brass and carbon steel in simulated atmospheric water under thin electrolyte layer has been investigated through gravimetric method, electrochemical tests, surface analysis and density functional theoretical (DFT) calculation. The inhibition efficiency has been discussed in the light of their chemical configuration.The polarization curves measurements showed that the anodic dissolution process of brass and carbon steel in simulated atmospheric water withβ-amino alcohols under thin electrolyate layer can be effectively retarded, indicating the the synthesized compounds were anodic inhibitors. Solution analysis showed that the Zn2+ concentration in blank solution was 0.0592mg/L, corresponding to the dezincification index was 0.94. When the concentration of DMP and DEAP at 10-2M, the Zn2+ concentration decreased 0.00143 mg/L and 0.00119 mg/L, relating to the dezincification index was 0.027 and 0.022. Electrochemical impedance spectroscopy (EIS) tests indicated that the impedance plots of brass in simulated atmospheric water with inhibitors under thin electrolyate layer were depressed shape, and the charge transfer resistance Rct, increased with the increase of inhibitor concentration, immersion time and alkyl chain length. The adsorption of MP, DMP, EAP, DEAP, DPAP and DBAP molecules on brass surface obeyed Langmuir isotherm model.The inhibiton efficiencies of brass increased with increase the concentration and alkyl chain length, and the inhibition effeiciency of MP, DMP, DEAP, DPAP and DBAP at 10-2M was obtained at 84.0%, 86.2%, 94.3%, 95.7% and 97.2%. It was found that theβ-amino alcohols easily adsorbed on the Zn domain, retarding the Zn dissolution in simulated atmospheric water under thin electrolyte layer by the stable inhibitor-metal complex film. DFT calculation was firstly used to investigate the adsorption mechanism ofβ-amino alcohol inhibitors. The results revealed that the hydrogen steric hindrance of MP in C1, C2, C3 and C4 atoms decreased the bond stable of HOMO of MP and brass d orbital, indicating the adsorption action was weak. While for DMP molecule, the hydrogen steric hindrance in C8, C9, C11 and C12 has been weaken due to the induced action by morpholin-4-yl group, suggesting the adsorption action was prounced by HOMO of DMP and brass d orbital. For EAR the electrons of HOMO in N3 and O9 was easily transitted and bonded with brass d orbital. The hydrophobic barrier action was decreased for the hydrogen distributed in the center sites of EAP. While for DEAP, the electron of HOMO in N38, O39 and O40 was easily transitted, then bonded with brass d orbital. The hydrogen in DEAP molecule distributed in the peripheral part, avail to the formation of effective hydrophobic barrier on metal surface.β-amino alcohol compounds DMP and DEAP, retarded the anodic dissolution of carbon steel in simulated atmospheric water under thin electrolyte layer, were anodic inhibitors. The inhibiton efficiency of DMP was 86.9% at 5×10-2M, whereas the inhibiton efficiency of DEAP obtained 95.0% at 2.5×10-2M. The potentiostatic map and Mulliken charges showed that the symmetric charge of N1 and N7, O4 and O10 in DMP were nearly equal, avail to the horizontal configuration adsorption. For DEAP, the symmetric charge C1 and C6, C5 and C10, N38 and N39 were marked discrepancy, resulting the formation of vertical and gradient configuration.
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