An overview of multifunctional epoxy nanocomposites. The EPPyN (Figure 6c), EPPyNG1 (Figure 6g), and EPPyNG3 (Figure 6i) showed the same trend. ; methodology, P.X. Graphene has higher aspect ratio than clay platelet, which can simultaneously improve not only the barrier properties, but also several mechanical, functional, and thermal properties of epoxy coatings [21,22]. The scanning electron microscopy (SEM) images of PPyN and PPyNG composites were obtained while using a Zeiss Sigma FE-SEM (Carl Zeiss AG, Geraniah, Germany). Figure S3 shows the Tafel curve of bare steel. Hosseini M.G., Sabouri M., Shahrabi T. Comparison of the corrosion protection of mild steel by polypyrrolephosphate and polypyrroletungstenate coatings. Parameters of Tafel polarization curve for coated Q235 substrates. In this study, the PPy nanowires were synthesized while using CTAB as soft template, and combined with graphene nanosheets by in situ oxidation polymerization. ; writingreview and editing, J.Z. ICPs have attracted tremendous attention due to a wide range of potential applications in sensors, supercapacitor electrodes, biological industries, and corrosion protection [10,11]. and then repeatedly washed by a large amount of water (46 times) until pH approached 10. A significantly positive shift Ecorr of 565 mV was obtained for the composites coating with PPyN, confirming that EPPyN engaged in redox reactions, resulting in the formation of metal oxide passive layer [20,42]. Moreover, ZSimpWin software further fitted the EIS measurements while using the equivalent electric circuits, as shown in Figure 7. ); moc.361@8211bewgnehz (W.Z. Schematic illustration of the preparation of waterborne epoxy/PPyNG coatings (EPPyNG) nanocomposite coatings. ; writingoriginal draft preparation, J.Z. Highly Aligned Ultrahigh Density Arrays of Conducting Polymer Nanorods using Block Copolymer Templates. 37 No. Liu T., Li J., Li X., Qiu S., Ye Y., Yang F., Zhao H. Effect of self-assembled tetraaniline nanofiber on the anticorrosion performance of waterborne epoxy coating. According to the above results, Figure 9 demonstrates the mechanism of corrosion protection for the mild steel substrate with neat epoxy coating and PPyNG nanocomposite coatings. Integration with montmorillonite and graphene turns out to be an effective method for avoiding aggregations and improve dispersion of PPy in the polymer matrix, which contributes to a great corrosion protection enhancement [6,19,20]. The potential dynamic polarization curves of blank epoxy, EPPyN, and EPPyNG coatings were performed with a sweep rate of 2 mV/s from the cathodic direction to the anodic direction. For comparison, the neat epoxy coating was also prepared through a similar method without loadings, which was named Blank. ; resources, W.Z. Revisiting graphenepolymer nanocomposite for enhancing anticorrosion performance: A new insight into interface chemistry and diffusion model. The potential of EPPyNG3 coating dropped sharply to 0.70 V after immersion 20 days, revealing that excess graphene was detrimental to the anticorrosion property [40]. ); moc.361@remylopcjr (J.R.); moc.361@fhzynnnus (H.Z. The electrolyte was 3.5 wt % NaCl solution. A study on the anticorrosion performance of epoxy nanocomposite coatings containing epoxy-silane treated nano-silica on mild steel substrate. Potentiodynamic polarization plots, impedance measurements, and fitted Rpore and Cc were used to study the anticorrosion performance of the coatings. Firstly, the PPy nanowires and PPyNG nanocomposites were completely dispersed in 10 mL of deionized water with a high-speed dispersion and then added into 30 g waterborne epoxy resin. Fabrication of graphene oxide/polypyrrole nanowire composite for high performance supercapacitor electrodes. The funding for this research was provided by the National Priorities Research Program of the Qatar National Research Fund (a member of Qatar Foundation) under the award no. Ghanbari A., Attar M.M. 51563011 and 2170436). The blocks are subjected to Southern Exposure testing. A ZQ-401 microscope was used to record the optical microscopic images of EPPyN coatings (Zhiqi Co., Ltd., Shanghai, China). However, from Figure 3d, the granular morphology of PPyNG3 was observed. Hence, the anti-corrosion performance of the EPPyNG nanocomposite coatings was significantly improved. (a,b) Equivalent electrical circuits of the coatings. The conjugation length of EPPyNG2 was longer than those of EPPyN and EPPyNG1, which resulted in electrons easier delocalization and in favor of the formation of passivation layers [51,52]. The EPPyNG2 coating had better barrier properties when compared to neat epoxy, because the well dispersed PPyNG could fill the structural and pinhole porosity of neat epoxy and then inhibited the water penetration. Polypyrrole Nanowire Actuators. Models (a) and (b) were fitted with the EIS data of pure epoxy coating and composites coatings, respectively. For the EPPyNG2 coatings, the Icorr was lowest than other coatings, which indicated the best anticorrosion performance in all of the studied samples, which corresponded to results of OCP tests. and J.W. Results of this study show that the durability of reinforced concrete (RC) structures with respect to corrosion could be enhanced by using ECR, especially in harsh climatic conditions. Figure 2 shows the FTIR spectra of the PPyN and PPyNG nanocomposites. Jadhav N., Vetter C.A., Gelling V.J. Open circuit potential (OCP) measurements, Tafel polarization curves, and electrochemical impedance spectroscopy (EIS) using an electrochemical workstation evaluated the anticorrosion properties of the waterborne epoxy/PPyNG coatings (EPPyNG). Federal government websites often end in .gov or .mil. Conjugation length of PPy was increased with the addition of graphene. The mild steels were polished while using 400 grift sand papers and then cleaned in ethanol and acetone. The impedance modulus dramatically decreased after 15 days and then progressively reduced with the increasing immersion time for all studied coatings, probably owing to the penetration of water and movement of ions through the coatings [50]. The following are available online at https://www.mdpi.com/2073-4360/11/12/1998/s1, Figure S1: t Water absorption of epoxy/polypyrrole nanowires coatings filled with 0%, 0.3%, 0.5% and 0.7% polypyrrole nanowires., Figure S2: Tafel curves of mild steel with coatings of epoxy/polypyrrole nanowires coatings filled with 0%, 0.3%, 0.5% and 0.7% polypyrrole nanowires in 3.5% sodium chloride solution after 20 days. Study on Enhancement Mechanism of Conductivity Induced by Graphene Oxide for Polypyrrole Nanocomposites. Chen C., Qiu S., Cui M., Qin S., Yan G., Zhao H., Wang L., Xue Q. Accessibility This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (, GUID:56E896E8-142E-4333-B406-A55CFF020CB8, polypyrrole nanowires, graphene, waterborne epoxy, corrosion protection. Field emission scanning electron microscope (FESEM) and Fourier transform infrared spectroscopy (FTIR) characterized the morphologies and structures of the synthesized PPyNG. The broad band at 30003500 cm1 arose from NH stretching vibrations [30]. Dutta D., Ganda A.N.F., Chih J.-K., Huang C.-C., Tseng C.-J., Su C.-Y. You may be able to access teaching notes by logging in via your Emerald profile. International Journal of Building Pathology and Adaptation. GJJ170680), National Natural Science Foundation of China (Contract No. Qiu S., Li W., Zheng W., Zhao H., Wang L. Synergistic Effect of Polypyrrole-Intercalated Graphene for Enhanced Corrosion Protection of Aqueous Coating in 3.5% NaCl Solution. The monitoring of OCP allowed for the assessment of the inclination of corrosion [39]. The electrochemical measurements were carried out to characterize the anticorrosive properties of blank epoxy, EPPyN and EPPyNG coatings using a CHI 660E electrochemical workstation (Chinstruments Co., Ltd., Shanghai, China) that was equipped with a conventional three-electrode cell with a saturated calomel electrode (SCE) as reference, a platinum counter electrode with 1 cm2 area, and a working electrode. Among them, polymer coatings are the most common approach for protecting metal surface from corrosion due to their low cost and high anticorrosion performance. Generally, a higher Rpore and lower Cc suggested that a small amount of corrosive media penetrated into the coatings [55]. The bare mild steels or mild steels with coatings were sealed while using sealant (paraffin: Rosin = 1:1) and Teflon to leave 1 cm2 area opening to the electrolytic solution. For pure epoxy coating, corrosive mediums (H2O, O2, and Cl-, etc.) It could be observed that the Rpore of neat epoxy coating gradually decreased from 7.3 105 cm2 to a much lower value (1.3 104 cm2). Loading PPy can also enhance the corrosion inhibiting properties of zinc-filled epoxy coatings [16,17]. The Rpore of coatings with EPPyN, EPPyNG1, and EPPyNG3 decreased to some extent, while the EPPyNG2 coating always maintained much higher values. The studied nanocomposite coating possessed superior corrosion protection performance when the graphene content of the filler was 2 wt %. Navarchian A.H., Joulazadeh M., Karimi F. Investigation of corrosion protection performance of epoxy coatings modified by polyaniline/clay nanocomposites on steel surfaces. Electrochemical behaviour of LiMn2O4PPy composite cathodes in the 4-V region. Furthermore, PPyN reacted with steel to form a dense layer of passive oxide film, which resulted in substantially reduced penetration of corrosive medias. In the anticorrosion field, the ICPs can be used to form a protective barrier layer and release inhibitors in the coating [12]. Kugler S., Kowalczyk K., Spychaj T. Influence of synthetic and bio-based amine curing agents on properties of solventless epoxy varnishes and coatings with carbon nanofillers. [29]. 100 g graphite (1 wt % equiv., 325 mesh) was then added in batches under stirring at 35 C for 2 h. The black flakes were filtered through a 200-mesh sieve and poured into 2 L of ice water after reaction. Figure S3: Tafel curve of the bare mild steel electrode. 657-678. https://doi.org/10.1108/IJBPA-12-2018-0099, Copyright 2019, Emerald Publishing Limited. The corrosion current density (Icorr), corrosion potential (Ecorr), anodic Tafel slope (ba), and cathodic Tafel slope (bc) were estimated from the Tafel extrapolation of anodic and cathodic lines to the point of intersection. Schematic illustration of corrosion protection of the mild steel with (a) neat epoxy coating and (b) EPPyNG composite coating. A precooled aqueous solution of 10 mL 0.2 M HCl containing 4 mmol APS was added into above solution in batches. The radius of capacitive impedance loop in high-frequency domain diminished during the immersion, which implied declined corrosion protective properties for mild steel. Armelin E., Pla R., Liesa F., Ramis X., Iribarren J.I., Alemn C. Corrosion protection with polyaniline and polypyrrole as anticorrosive additives for epoxy paint. Kalendov A., Vesel D., Kohl M., Stejskal J. Anticorrosion efficiency of zinc-filled epoxy coatings containing conducting polymers and pigments. Rpore modeled ionically conducting paths across the coating, which could be used to evaluate the barrier performance of the coatings [54]. about navigating our updated article layout. All of the electrochemical tests were conducted at room temperature. sharing sensitive information, make sure youre on a federal Zhong W., Liu S., Chen X., Wang Y., Yang W. High-Yield Synthesis of Superhydrophilic Polypyrrole Nanowire Networks. (a) Rpore and (b) Cc values with immersion in 3.5 wt % NaCl solution. If you think you should have access to this content, click to contact our support team. Fourier transform infrared spectroscopy (FTIR) spectrum of the PPyN, PPyNG1, PPyNG2, and PPyNG3. Gergely A., Pfeifer ., Bertti I., Trk T., Klmn E. Corrosion protection of cold-rolled steel by zinc-rich epoxy paint coatings loaded with nano-size alumina supported polypyrrole. Up to now, there has been no report on using PPy nanowire as additive for waterborne anticorrosion coatings. The higher barrier properties of nanocomposite coating and passivation effect of polypyrrole nanowires were beneficial in corrosion protection. The corrosion performance of mild steel and ECR in concrete under a simulating splash zone environment is evaluated. Rp is the polarization resistance calculated by the slope of the polarization curve at the Ecorr according to the SternGeary Equation (2) [45]: Here, ba and bc are the anodic and cathodic Tafel slopes, Icorr is the corrosion current density. The SEM image (Figure 3a) revealed the uniform nanowire structure with an average diameter of about 50 nm and length of several micrometers. 5, pp. It indicated that the oxidative PPy functional fillers passivated the steel, resulting in higher OCP [18]. 8600 Rockville Pike Graphene was prepared by following the method by Dong et al. ); moc.361@pxyranidro (P.X. For the convenience discussion, the present nanocomposite referred to as PPyNG, and nanocomposite coating corresponded to the epoxy/PPyNG coating. We thank Jiangxi Key Laboratory of Surface Engineering for SEM characterization. EIS is a powerful tool for investigating the corrosion protection of the coatings [47]. Arefinia R., Shojaei A., Shariatpanahi H., Neshati J. Anticorrosion properties of smart coating based on polyaniline nanoparticles/epoxy-ester system. The Icorr values of EPPyNG1 and EPPyNG2 coated mild steel considerably decreased when compared with EPPyN. The 0.5% additive based on the total formulation was finally determined. ), 2Department of Applied Physics, School of Science, East China Jiaotong University, Nanchang 330013, China; moc.621@tpo_gnehcqz. The effect of polymer morphology on the performance of a corrosion inhibiting polypyrrole/aluminum flake composite pigment. Pretreated graphite was then dispersed in the alkali water (pH = 14) under ultrasonication while using a sonic vibra-cell VC505 processor in 60% power for 1 h, resulting in black graphene slurry. The dry coating thickness was around 37 m. The Martin-Gallego M., Verdejo R., Lopez-Manchado M.A., Sangermano M. Epoxy-Graphene UV-cured nanocomposites. The EPPyNG3 coating also exhibited lower Rpore and higher Cc than EPPyNG2, which confirmed that excess graphene induced the defect coating and reduced corrosion protection. Before The calculated vcorr value of 8.9 105 mm/year for EPPyNG2 was about 100 times lower than that for blank epoxy coating. government site. It would not only result in economic losses, but also threaten the safety of industrial production. This research was funded by Natural Science Foundation of Jiangxi Education Department (Contract No. The resulting coating was obtained after curing for 48 h at room temperature. and J.Z. The Q235 mild steels (C: 0.14%, Mn: 0.3%, S: 0.05%, P: 0.045%, and rest being Fe) with area of 42 mm 10 mm were purchased from Biuged Laboratory Instruments (Guangzhou) Co., Ltd. (Guangzhou, China). In brief, 100 g KMnO4 (1 wt % equiv.) FOIA Subsequently, 30 wt % H2O2 was added to decompose the insoluble manganese dioxide. Berdichevsky Y., Lo Y.H. ; funding acquisition, J.Z., F.G. and L.S. ); nc.moc.untsxj@6102oagief (F.G.); nc.moc.untsxj@7240fheh (H.H. However, the coating with excess graphene (EPPyNG3) exhibited lower Ecorr than EPPyNG2, probably because larger fraction of graphene affected the growth of PPy nanowires and induced the defects in PPyNG3 composites [38], which was in agreement with the results of SEM. The authors declare no conflict of interest. official website and that any information you provide is encrypted The Fourier transform infrared spectrometer (FTIR) spectra of PPyNG films were collected by a Bruker-Veretex70 spectrometer (Bruker Company, Karlsruhe, Germany) while using KBr pellets. http://creativecommons.org/licenses/by/4.0/, https://www.mdpi.com/2073-4360/11/12/1998/s1. The site is secure. Polypyrrole nanowires/graphene (PPyNG) nanocomposites as anticorrosive fillers were prepared by in situ polymerization in order to improve the anticorrosion performance of waterborne epoxy coatings. Achieving high performance corrosion and wear resistant epoxy coatings via incorporation of noncovalent functionalized graphene. Wei H., Ding D., Wei S., Guo Z. Anticorrosive conductive polyurethane multiwalled carbon nanotube nanocomposites. The PPy nanowires/graphene nanocomposite coating exhibited improved anticorrosion performance in comparison with pure epoxy and epoxy/PPy nanowires samples. Lei W., He P., Wang Y., Zhang S., Dong F., Liu H. Soft template interfacial growth of novel ultralong polypyrrole nanowires for electrochemical energy storage. After that, the PPyNG nanocomposites were incorporated into waterborne epoxy coatings to study their anticorrosion performance for mild steel. The .gov means its official. Therefore, the EPPyNG3 (1.6 106 cm2) displayed worse anticorrosive property when compared with EPPyNG2. The bands at 1048 and 1321 cm1 were attributed to CH deformation vibrations and CN stretching vibrations, respectively [32]. It was worth noting that the CN stretching vibrations peak of PPyNG nanocomposites had been downshifted to 1310 cm1, which was probably due to the interactions between graphene layers and aromatic polypyrrole rings [34]. ; data curation, Y.D. Lei Y., Qiu Z., Liu J., Li D., Tan N., Liu T., Zhang Y., Chang X., Gu Y., Yin Y. Careers. Synthesis, Structural, and Morphological Characterizations of Reduced Graphene Oxide-Supported Polypyrrole Anode Catalysts for Improved Microbial Fuel Cell Performances. All of the chemicals were of analytical reagent grade and used without further purification. By addition of PPyNG, the Ecorr dramatically increased to 537 mV with 1 wt % graphene and 482 mV with 2 wt % graphene. Gu H., Ma C., Gu J., Guo J., Yan X., Huang J., Zhang Q., Guo Z. Qiu S., Chen C., Cui M., Li W., Zhao H., Wang L. Corrosion protection performance of waterborne epoxy coatings containing self-doped polyaniline nanofiber. in an ice-water bath. Lee J.I., Cho S.H., Park S.-M., Kim J.K., Kim J.K., Yu J.-W., Kim Y.C., Russell T.P. Figure 5 shows the Tafel curves of the as prepared coatings immersion in corrosive solutions. Licensee MDPI, Basel, Switzerland. Its corrosion rate was about 100 times lower than that of neat epoxy coating. The prepared graphene was re-dispersed in N-methyl pyrrolidone (NMP) for further use. Investigation, Y.D. Mild steel BB showed a high corrosion current density of 1.24A/ cm2 in Tafel plots and a very low polarization resistance of 4.5 k cm2 in LPR technique, whereas very high charge transfer resistance of 1672 and 1675 k cm2 is observed on ECR and ECR with controlled damage (ECRCD), through EIS technique, respectively. Meanwhile, the well-dispersed PPyNG could block the coating pores and decrease the corrosive medias diffusion toward the substrate. You can join in the discussion by joining the community or logging in here.You can also find out more about Emerald Engage. The isolated graphene nanosheets could also be seen due to increasing concentration of graphene nanosheets. The characteristic polypyrrole peaks located at 1558 and 1478 cm1 were due to the asymmetric and symmetric ring-stretching modes, respectively [31]. will also be available for a limited time. Kumar A., Ghosh P.K., Yadav K.L., Kumar K. Thermo-mechanical and anti-corrosive properties of MWCNT/epoxy nanocomposite fabricated by innovative dispersion technique. National Library of Medicine The purpose of this paper is to present the results of a two-year long study carried out in order to evaluate the corrosion performance of mild steel bare bars (BB) and epoxy-coated rebar (ECR) in concrete under a simulated harsh environment of chlorides. In the case of protection efficiency, the highest PE value from EPPyNG2 (99.9%) described that PPyNG2 loading in the epoxy coating can provide superior inhibition corrosion performance. The electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and Tafel plot are performed to measure the polarization resistance and corrosion current densities of these rebars. After two years of immersion in 3.89 percent NaCl solution, the mild steel BB were severely corroded and a considerable weight loss was observed, whereas under heavy chloride attack, ECR showed no deterioration of epoxy coating and neither any corrosion of underlying steel. was added in batches into concentrated H2SO4 (2 L, 98%) over a period of 45 min. In this paper, the PPy nanowires (PPyN) were prepared by a soft template method. The electroactive nature of PPy allows for it to oxidize the metal substrate, which results in the formation of a passive oxide layer at the interface between the PPy and underlying metal substrate [14]. Next, 10 g curing agent was added into the above dispersive media and the mixture was painted on the pretreated mild steels. An official website of the United States government. PMC legacy view Highly exfoliated GO-PPy-Ag ternary nanocomposite for electrochemical supercapacitor. Shchukin D.G., Zheludkevich M., Yasakau K., Lamaka S., Ferreira M.G.S., Mhwald H. Layer-by-Layer Assembled Nanocontainers for Self-Healing Corrosion Protection. Although EPPyNG3 possessed longer conjugation length, its excess graphene content might increase the defects due to influence of polypyrrole nanowires, and probably generated micro galvanic corrosion that showed the corrosion-promotion activity [53]. Contri G., Barra G.M.O., Ramoa S.D.A.S., Merlini C., Ecco L.G., Souza F.S., Spinelli A. Epoxy coating based on montmorillonite-polypyrrole: Electrical properties and prospective application on corrosion protection of steel. Yeh J.-M., Chin C.-P., Chang S. Enhanced corrosion protection coatings prepared from soluble electronically conductive polypyrrole-clay nanocomposite materials. Effect of Conducting Polyaniline/Graphene Nanosheet Content on the Corrosion Behavior of Zinc-Rich Epoxy Primers in 3.5% NaCl Solution. The ratio was 0.1304, 0.1328, 0.1427, and 0.1515 for PPy, PPyNG1, PPyNG2, and PPyNG3, respectively, which suggested that the conjugation length increased with further incorporation of the graphene. In contrast, the EPPyNG2 displayed a much lower Cc value when compared to those of neat epoxy and EPPyN coating. Evidence of redox interactions between polypyrrole and Fe3O4 in polypyrroleFe3O4 composite films. Among the available ICPs, polypyrrole (PPy) is the most promising polymer due to its easy polymerization, mechanical stability, and better biocompatibility, as well as tunable electrical property [13]. The resulting product was filtered and rinsed with deionized water and ethanol (46 times) until the filtrate was colorless. In addition, the peaks that were centered at 1202 and 923 cm1 were assigned to the doping states of PPy [33]. The molecule structures and morphologies of the PPyNG nanocomposites were also analyzed. However, even these coatings fail over prolonged exposure in corrosive media [4]. and H.H. Optical microscopic images of epoxy/polypyrrole nanowires coatings filled with 0%, 0.3%, 0.5% and 0.7% polypyrrole nanowires. Liu S., Gu L., Zhao H., Chen J., Yu H. Corrosion Resistance of Graphene-Reinforced Waterborne Epoxy Coatings. Nguyen Thi T., Dinh Thi Mai T., Pham Thi N., Nguyen Thu P., Vu Thi Hai V., Ngo Quang M. Enhanced Anti-Corrosion Protection of Carbon Steel with Silica-Polypyrrole-Dodecyl Sulfate Incorporated into Epoxy Coating. NPRP 7-410-2-169. Received 2019 Oct 31; Accepted 2019 Nov 29. Hexion Inc. (Columbus, Ohio, US) provided waterborne epoxy resin (Epikote 6520-WH-53) and curing agent (Epikur 8538-Y-68). Learn more Visit emeraldpublishing.com/platformupdate to discover the latest news and updates, Answers to the most commonly asked questions here. Dubal D.P., Caban-Huertas Z., Holze R., Gomez-Romero P. Growth of polypyrrole nanostructures through reactive templates for energy storage applications. The prepared epoxy coatings that were loaded with PPy nanowires, PPyNG1, PPyNG2, and PPyNG3 were denoted as EPPyN, EPPyNG1, EPPyNG2 and EPPyNG3, respectively. Figure 1 shows the preparation process for the fabrication of waterborne epoxy/PPyNG coatings (EPPyNG) coating materials. Singu B.S., Yoon K.R. However, for the EPPyNG2 coating, the radius of capacitive impedance arc at low frequency region in the immersion seven days suddenly expanded beyond that of three days, which suggested that PPy might react to passivate the metal substrate [23]. The PPyN/graphene (PPyNG) nanocomposites were synthesized through in situ polymerization. The passivation layer effectively prevented the steel from corrosion. The reaction was allowed to proceed under stirring for 4 h at about 05 C. The first semicircle at high frequency region and the second part at middle-low frequency region were due to the impedance of coating and corrosion reactions, respectively [48]. The Ecorr of the neat epoxy resin coated mild steel was 784 mV. Naveen M.H., Gurudatt N.G., Shim Y.-B. ; validation, J.R.; formal analysis, H.Z. EIS was able to detect the defects in epoxy. Ding J., Zhao H., Xu B., Zhao X., Su S., Yu H. Superanticorrosive Graphene Nanosheets through Deposition of Boron Nitride Nanodots.
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