Papers by Mohammad Mahdavian
Improving the Protection Performance of AA2024-T3 in 3.5 wt% NaCl Solution Using the Synergistic Effect of Cerium Cations and Diethyldithiocarbamate Molecules
Journal of The Electrochemical Society, 2020
In the present work, the synergistic effect of diethyldithiocarbamate (DDTC) molecules and Ce3+ c... more In the present work, the synergistic effect of diethyldithiocarbamate (DDTC) molecules and Ce3+ cations on the corrosion inhibition of the 2024-T3 aluminum alloy was assessed by employing surface analysis and electrochemical tests. For this purpose, potentiodynamic polarization, and electrochemical impedance spectroscopy were measured in the presence of Ce3+ cations and DDTC molecules. Also, surface analysis methods were employed to study the mechanisms of the inhibition in the presence of the Ce3+ cations and DDTC molecules. The results showed strong synergism between the DDTC molecules and Ce3+ cations due to the creation of a complex film on the surface of AA2024-T3. The complex film formation on the AA2024-T3 surface was proved using scanning electron microscopy, X-ray photoelectron spectroscopy, and attenuated total reflection Fourier-transform infrared spectroscopy. Also, cathodic inhibition behavior and a wide passivation range attributed to the Ce+DDTC system were illustrate...
Chemical modification of LDH conversion coating with diethyldithiocarbamate as a novel anti-corrosive film for AA2024-T3
Journal of Industrial and Engineering Chemistry, 2021
Abstract Nowadays, layered double hydroxide conversion coatings are a potential eco-friendly alte... more Abstract Nowadays, layered double hydroxide conversion coatings are a potential eco-friendly alternative for hazardous and carcinogenic chromate conversion coatings. In this work, Zn-Al LDH conversion coating (LDH−CC) modified with diethyldithiocarbamate (DEDTC) molecules, as a smart inhibitive film, was synthesized on AA2024-T3. For this purpose, the LDH−CC was prepared on the AA2024-T3 by an in-situ hydrothermal route, and then intercalated with DEDTC molecules through an anion-exchange procedure. The intercalation of the DEDTC into the structure of the LDH−CC was studied using XPS, XRD, ATR-FTIR, SEM-EDS, and TGA techniques. All of the characterization techniques proved the successful intercalation of the DEDTC molecules in the structure of the LDH−CC. Results indicated that the chemical modification treatment increases in the gallery space of LDH−CC by the intercalation of DEDEC molecules in the coating structure. Also, electrochemical tests were implemented in 3.5 wt. % NaCl media to study the anti-corrosion performance of the coatings. The electrochemical test results showed that the presence of the DEDTC molecules dramatically enhanced the anti-corrosion behavior of the LDH−CC due to the induction of the active inhibition mechanism.
Zn-Al layered double hydroxide as an inhibitive conversion coating developed on AA2024-T3 by one-step hydrothermal crystallization: Crystal structure evolution and corrosion protection performance
Surface and Coatings Technology, 2021
Abstract In the present work, a Zn Al layered double hydroxide (LDH) conversion coating was synth... more Abstract In the present work, a Zn Al layered double hydroxide (LDH) conversion coating was synthesized on 2024-T3 aluminum alloy by a one-step hydrothermal method. For this purpose, the effect of synthesis parameters, including the amount of Zn2+ cations and hexamethylenetetramine molecules, on the structural changes were evaluated by using the scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) analysis and X-ray diffraction (XRD) spectroscopy. Also, benzimidazole (BI), as corrosion inhibitor of the AA2024-T3, was intercalated into the LDH film structure by an anion-exchange process. The intercalation of BI molecules into the LHD structure was studied using the SEM-EDS and XRD analysis. Furthermore, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PD), and electrochemical current noise measurements were employed in 3.5 wt% NaCl solution to assess the protection performance of the LDH coating. The PD test results showed that the LDH conversion coating's polarization resistance increases from 24.05 to 131.1 kΩ/cm2 after the intercalation of the BI molecules into the structure of the Zn Al LDH layer. The induction of active protection performance for the LDH film modified with BI molecules was demonstrated through the EIS test results.
Effect of Nanosilica and Boron Carbide on Adhesion Strength of High Temperature Adhesive Based on Phenolic Resin for Graphite Bonding
Ind. Eng. Chem. Res., 2014
ABSTRACT
Effect of aging time on corrosion inhibition of cationic surfactant on mild steel in sulfamic acid cleaning solution
Corrosion Science, 2013
The stability of the 1 M sulfamic acid solutions containing a gemini cationic surfactant (12-4-12... more The stability of the 1 M sulfamic acid solutions containing a gemini cationic surfactant (12-4-12) or its monomeric counterpart (DTAB) during 23 days of storage were studied by electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and surface tension measurements. The EIS studies indicated that in comparison to DTAB solution, 12-4-12 solution considerably retained the corrosion inhibition during the storage period. The surface tension of DTAB solution was increased around 10 mN/m during storage while the surface tension of 12-4-12 solution was almost unchanged. The higher stability of 12-4-12 acidic solution than that of DTAB was also depicted by XRD results.► Stability of surfactants in sulfamic acid solution regarding corrosion inhibition. ► Stability of surfactants in sulfamic acid solution regarding surface tension. ► Evaluation of surface energy of mild steel in aged and fresh acid solutions. ► Evaluation of surface morphology of mild steel in aged and fresh acid solutions. ► Characterization of the aged solutions by XRD.
Electrochemical examining behavior of epoxy coating incorporating zinc-free phosphate-based anticorrosion pigment
Progress in Organic Coatings, 2013
Protective performance of the epoxy primer containing strontium aluminum polyphosphate (SAPP) as ... more Protective performance of the epoxy primer containing strontium aluminum polyphosphate (SAPP) as a zinc-free phosphate-based anticorrosion pigment is aimed to assess in this work through taking advantage of electrochemical impedance spectroscopy (EIS) and electrochemical noise method (ENM). The absence of zinc offers an excellent environmentally friendly profile to the class of inhibiting compound. In the pigment extracts, the electrochemical techniques revealed superiority of SAPP compared to the conventional zinc phosphate (ZP). The behavior was connected to precipitation of a protective layer on the surface exposed to SAPP. In comparison with ZP, the most effective SAPP content in the protective primer was then determined using EIS.► Try to find a proper alternative for zinc phosphate revealing undesirable performance. ► Coating formulation using SAPP as zinc-free phosphate based anticorrosion pigment. ► Studying corrosion inhibition of SAPP in solution phase with the use of EIS and ENM. ► EIS examining the behavior of coatings with complete formulation including SAPP. ► Determining the most effective SAPP pigment content in the protective epoxy primer.
Optimization of potassium zinc phosphate anticorrosion pigment by Taguchi experimental design
Progress in Organic Coatings, 2013
The synthesis condition of potassium zinc phosphate pigment was optimized with respect to corrosi... more The synthesis condition of potassium zinc phosphate pigment was optimized with respect to corrosion inhibition in extract solution and dispersion stability in an epoxy resin by application of Taguchi experimental design. Processing parameters, including calcinations time, quiescent time, mixing rate and KOH/ZnCl2 mole ratio are selected as the influential parameters. Corrosion inhibition of the pigments in the extract solutions and dispersion stability in the epoxy resin were evaluated by electrochemical impedance spectroscopy (EIS) and turbidity measurement, respectively. The pigment synthesized under optimal condition was characterized by XRD, which showed formation of KZnPO4 and KZn2PO4(HPO4). Corrosion protection of the epoxy coating containing synthesized pigment at optimal condition was evaluated by salt spray and compared to the unpigmented epoxy coating. Salt spray results showed higher corrosion protection of the epoxy coating in the presence of potassium zinc phosphate, which could be attributed to lower diffusivity of the pigmented coating to Cl− or formation of phosphate layer confirmed by SEM–EDX.► Synthesis of potassium zinc phosphate pigment by Taguchi experimental design. ► Finding optimal synthesis condition regarding to anticorrosion properties. ► Finding optimal synthesis condition regarding to dispersion stability. ► Characterization of the synthesized pigment at optimal condition by XRD. ► Evaluation of the synthesized pigment at optimal condition by salt spray.
The influence of nanosilver on thermal and antibacterial properties of a 2K waterborne polyurethane coating
Progress in Organic …, Jan 1, 2012
ABSTRACT A two-component (2 K) waterborne polyurethane coating containing nanosilver (200 ppm) wa... more ABSTRACT A two-component (2 K) waterborne polyurethane coating containing nanosilver (200 ppm) was prepared and compared to the blank coating with no nanosilver. The coatings were inoculated with Escherichia coli and Staphylococcus aureus by the agar-well diffusion method. According to the results, silver nanocomposite coating exhibited a growth reduction on both types of bacteria. The cross-section of samples was examined by scanning electron microscopy (SEM). The micrographs depicted uniform dispersion of Ag nanoparticles in the polyurethane matrix. Fourier transform infra-red (FTIR) spectra of the coatings revealed intensification of carbonyl group stretching band in the presence of nanosilver, which could be related to the partial protection of isocyanate groups from decomposition in the presence of water. Enhancement of thermal properties was observed by differential scanning calorimetry and thermogravimetry.
A comparative study on the electrochemical behavior of mild steel in sulfamic acid solution in the presence of monomeric and gemini surfactants
Journal of Surfactants and …
Electrochimica acta, Jan 1, 2007
Mercapto functional azole compounds as organic corrosion inhibitors in a polyester-melamine coating
Progress in Organic Coatings, Jan 1, 2010
... Two mercapto functional azole compounds including 2-mercaptobenzimidazole (MBI) and2-mercapto... more ... Two mercapto functional azole compounds including 2-mercaptobenzimidazole (MBI) and2-mercaptobenzoxazole (MBO) were ... in different frontier orbital energies, dipole moment, atomic charges [17] which consequently affects their corrosion inhibition performance. ...
Corrosion science, Jan 1, 2006
Surface and Coatings Technology, Jan 1, 2009
The effect of benzimidazole and zinc acetylacetonate mixture on cathodic disbonding of epoxy coated mild steel
Progress in Organic Coatings, Jan 1, 2009
Electrochemical behavior of mild steel in the presence of zinc acetylacetonate (Zn(acac) 2 ) and ... more Electrochemical behavior of mild steel in the presence of zinc acetylacetonate (Zn(acac) 2 ) and benzimidazole (BIMIDA) was evaluated by electrochemical impedance spectroscopy (EIS) in 3.5% NaCl solution and compared to zinc phosphate (ZP) pigment and zinc potassium ...
Corrosion inhibition performance of 2-mercaptobenzimidazole and 2-mercaptobenzoxazole compounds for protection of mild steel in hydrochloric acid solution
Electrochimica Acta, Jan 1, 2010
The effect of some mercapto functional azole compounds on the corrosion of mild steel in 1 M hydr... more The effect of some mercapto functional azole compounds on the corrosion of mild steel in 1 M hydrochloric acid solution was studied by polarization and electrochemical impedance spectroscopy (EIS). Polarization studies showed depression of cathodic and anodic polarization curves ...
Corrosion inhibition performance of three imidazole derivatives on mild steel in 1 M phosphoric acid
Materials Chemistry and Physics, Jan 1, 2010
The effect of benzimidazole (BI), 2-methyl benzimidazole (2MBI) and 2-aminobenzimidazole (2ABI) o... more The effect of benzimidazole (BI), 2-methyl benzimidazole (2MBI) and 2-aminobenzimidazole (2ABI) on the corrosion of mild steel was evaluated in 1 M phosphoric acid at various concentrations using electrochemical techniques (Electrochemical Impedance Spectroscopy (EIS) and ...
Electrochimica Acta, Jan 1, 2009
Corrosion Science, Jan 1, 2009
Corrosion inhibition of mild steel in sodium chloride solution by some zinc complexes
Corrosion Science, Jan 1, 2010
... References [1] M. Saremi, N. Parsi, c. Dehghanian, Corrosion 65 (2009) 778-784. [2] MS Vukaso... more ... References [1] M. Saremi, N. Parsi, c. Dehghanian, Corrosion 65 (2009) 778-784. [2] MS Vukasovich, DR Robitaille, J. Less-Common Met. 54 (1977) 437-448. ... Sci. 40 (1998) 673-691. [11] MA Amin, SS Abd El Rehim, AS El-Lithy, Corros. Sci. 52 (2010) 3099-3108. ...
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Papers by Mohammad Mahdavian