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Öğe Corrosion protection of Q235 steel in Pseudomonas aeruginosa-laden seawater environment using high barrier PDMS nanocomposite coating(Springer International Publishing, 2023) Arukalam, Innocent O.; Uzochukwu, Ikechukwu N.; Izionworu, Vincent O.; Tüzün, Burak; Dagdag, O.Perfluorodecyltrichlorosilane (PFDS)-modified PDMS-ZnO hydrophobic coating and 2-ethylhexanoic acid (EHA)/PFDS-modified amphiphilic coating were fabricated. The effect of EHA on the barrier properties and corrosion protection effectiveness of PFDS-modified hydrophobic PDMS-ZnO coating was investigated using electrochemical impedance spectroscopy (EIS) and molecular dynamics simulation techniques. The EIS results showed the amphiphilic coating exhibited higher barrier and corrosion protection properties than the hydrophobic coating. The observed EIS results were confirmed by results of the water contact angle measurement, SEM, AFM, EDS and FTIR. The molecular dynamics (MD) simulation results revealed the nature of interaction between the amphiphilic coating and the corrodent, as well as the interaction between hydrophobic coating and the corrodent. The results clearly indicate that amphiphilic coating was most favourable for hydrophilic interaction, whereas the hydrophobic coating was well-disposed to hydrophobic interaction. These agree with the experimental results. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2023.Öğe Cyclotriphosphazene based dendrimeric epoxy resin as an anti-corrosive material for copper in 3% NaCl: Experimental and computational demonstrations(Elsevier, 2020) Dagdag, O.; El Harfi, A.; Safi, Zaki; Guo, Lei; Kaya, Savas; Verma, Chandrabhan; Ebenso, E. E.Present study deals with the synthesis, characterization and corrosion inhibition effect of a hexafunctional cyclotriphosphazene derivative, namely 2,2,4,4,6,6-hexakis(oxiran-2-ylmethoxy)-1,3,5,2 delta, 4 delta,6 delta-triazatriphosphinine(HPGCP)for copper in 3 wt% NaCl medium. The synthesized HPGCP was characterized using numerous spectral techniques such as H-1, C-13, P-31 NMR (Nuclear magnetic resonance) and Fouriertransform infrared spectroscopy (FT-IR) methods. Anti-corrosive effect of the HPGCP was measured using electrochemical and computational methods. Results showed that HPGCP exhibited highest protection efficiency of 95% at as low as 10(-3) M concentration. Polarization studies showed that HPGCP acted as mixed type inhibitor and its adsorption obeyed the Langmuir adsorption isotherm model. Density Functional Theory (DFT) based computational studies demonstrate that HPGCP interacts with copper surface using donor-acceptor interactions inwhich three nitrogen atoms and six p-electrons of the cyclotriphosphazene ring play significant role in metalinhibitor interactions. Molecular dynamic (MD) simulations study demonstrated that HPGCP spontaneously interacts withmetallic surface using its electron rich centers and acquires the planar orientation. Experimental results were well corroborated with the computational results. (C) 2020 Elsevier B.V. All rights reserved.Öğe Epoxy prepolymer as a novel anti-corrosive material for carbon steel in acidic solution: Electrochemical, surface and computational studies(Elsevier, 2020) Dagdag, O.; Safi, Zaki; Erramli, H.; Wazzan, Nuha; Guo, Lei; Verma, Chandrabhan; Ebenso, E. E.Atetra-functional aromatic epoxy prepolymer namely, 4, 4'-(ethane-1, 2-diyl) bis (N, N-bis (oxiran-2-ylmethyl) aniline) (AA1) was synthesized as evaluated corrosion inhibitor for carbon steel. TheAA1 was characterized using H-1 NMR and FT-IR methods. The anti-corrosive property of AA1 for carbon steel corrosion in 1M HCl solution was evaluated using several experimental and computational techniques. The AA1 showed highest efficiency of 96.5 % at 10(-3)M concentration. PDP study suggested that AA1 behaves slight anodic predominance and its adsorption of the AA1 obeyed the Langmuir adsorption isotherm model. DFT study conducted in neutral as well as protonated forms suggested that AA1 acts as efficient anti-corrosive material under both the conditions and its adsorption mainly takes place through polar heteroatoms (N and O) and two aromatic rings as HOMO and LUMO are mainly localized over the center part of the AA1 molecule. MDS suggested that AA1 adsorbs using its flat orientation and its adsorption decreases with rise in temperature. Adsorption energies were in negative indicating that AA1 adsorption occurs spontaneously as all studied temperatures.Öğe Influence of ZnO Nanoparticle Size on Barrier Performance and Corrosion Protection of Poly(dimethylsiloxane)-Coated Q235 Steel in Chloride Environment: Bode and Computational Simulation Investigations(Springernature, 2024) Arukalam, Innocent O.; Uzochukwu, Ikechukwu N.; Tuezuen, Burak; Dagdag, O.; Oguzie, Emeka E.Ethylhexanoic acid-modified PDMS-ZnO nanocoatings containing varying dimensions of ZnO nanoparticles (30, 50 and 90 nm) were prepared. The main objective was to appraise the effect of varying dimensions of ZnO nanoparticles on the protective efficacy of ethylhexanoic acid-modified PDMS coating in aqueous solution of 3.5 wt% NaCl/Pseudomonas aeruginosa. Barrier properties and anti-corrosion performance of the coatings were evaluated by electrochemical impedance spectroscopy (EIS). Computational simulation techniques [quantum chemical computation (QCC) via density functional theory (DFT) and molecular dynamics (MD) simulation] were employed to provide molecular/atomistic level information on the chemical molecules responsible for corrosion protection performance and their adsorption phenomena. EIS results showed that the coating containing 30 nm ZnO nanoparticles maintained high impedance values in the order of 109 magnitude throughout the immersion periods. The obtained results were validated by wettability, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy results. The DFT calculations showed that PDMS and ethylhexanoic acid with energy gaps of 5.123 and 5.337 eV, respectively, are most responsible for the corrosion protection effect. The good adsorption of the coating containing 30 nm ZnO particles was validated by MD simulation result with adsorption energies (Eads) of - 2.28 kcal/mol, suggesting it is most susceptible for hydrophilic interaction.
