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A brief review of corrosion protective films and coatings based on graphene and graphene oxide

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Abstract

This paper briefly introduced the application of graphene and graphene oxide in the field of corrosion protection, including graphene films and graphene-based organic coatings. In the description of the graphene films, the preparation methods, protective performance, corrosion protective mechanism, practical problems and the improvement methods were emphasized. In terms of graphene-based organic coatings, the modification and dispersion of graphene and graphene oxide, the function integration of graphene and application in organic coatings, and the influence of the electrical conductivity were mainly introduced.

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... However, major difficulties may occur with the dispersion of the GO nanosheets in polymer matrices. The nanoparticle tendency to form agglomerates due to their large surface area and surface energy [9] provides obstacles in achieving great results. The simplest and most efficient way to prevent the agglomeration of the nanoplatelets is through chemical functionalization [10]. ...
... The simplest and most efficient way to prevent the agglomeration of the nanoplatelets is through chemical functionalization [10]. Various studies have investigated the chemical functionalization of GO [9,11], which is achievable thanks to the hydroxyl, carboxyl and epoxy groups found on its basal plane and edges [7]. Some of the utilized modifications were carried out by titanate TiO 3 2− coupling agent [12], inorganic nano-oxides (ZnO, TiO 2 ) [13,14], corrosion inhibitors (amino-azobenzene, diamino-azobenzene, metronidazole) [9,15], silane coupling agents (APTES) [1,7,16,17], and PAMAM dendrimer [10,18]. ...
... Various studies have investigated the chemical functionalization of GO [9,11], which is achievable thanks to the hydroxyl, carboxyl and epoxy groups found on its basal plane and edges [7]. Some of the utilized modifications were carried out by titanate TiO 3 2− coupling agent [12], inorganic nano-oxides (ZnO, TiO 2 ) [13,14], corrosion inhibitors (amino-azobenzene, diamino-azobenzene, metronidazole) [9,15], silane coupling agents (APTES) [1,7,16,17], and PAMAM dendrimer [10,18]. ...
Article
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The aim of the paper is to carry out a detailed investigation of the effect of graphene oxide-poly(amidoamine) (GO-PAMAM) incorporated in silica matrices on the corrosion behaviour of zinc. GO was modified with PAMAM dendrimer in order to improve its dispersion in the silica coatings prepared on zinc by dip-coating. Morpho-structural and physico-chemical characterization of the graphenes were made by FT-IR and Raman spectroscopy, TEM, and XRD. After incorporation, the effect of graphenes on the anti-corrosive performance of silica-coated zinc was investigated by electrochemical impedance spectroscopy. The results revealed that GO-PAMAM nanosheets dispersed in silica matrix significantly improved the corrosion resistance of the coatings. The polarization resistance Rp increased from 680 to 2489 kΩ cm2. The performances of SiO2-GO-PAMAM coatings were compared with those of SiO2 coatings incorporating GO, reduced graphene oxide (rGO), and 3-aminopropyl triethoxysilane (APTES)-modified GO. The influence of silica sol-ageing of the composite coatings was also investigated, as the polycondensation plays an important role in its anti-corrosive properties. The morphology of the composite coatings was examined by SEM, and their wettability by contact angle measurements. The protection offered by the SiO2-GO-PAMAM composite material is the leading. This can be associated with the GO-PAMAM’s high oxidation degree, low electrical conductivity, and by the fact that reduces the penetration of the electrolyte into the silica/zinc interface.
... Nanomaterials have strange and valuable properties compared with bulk materials and because of that are widely used for different purposes especially for sensing purposes [1][2][3][4][5][6][7][8][9][10]. Graphene is a two-dimensional carbon nanomaterial which is not only a flexible structure but also is a robust structure which make it to be very useful for different applications [1]. ...
... The graphene because of having good electrical, thermal and optical properties, has a great potential for application to developing transistors [2,4], chemical and electrochemical sensors [5] and biological sensors [6]. The graphene has some extra applications in surface coatings for inhibiting corrosions [7,8] and to reduce wear and friction on sliding metal surfaces [9,10]. The graphene sheets with lateral dimensions less than one hundred nanometers are called graphene quantum dots (GR) which have new chemical and physical properties such as high stability, good solubility, low toxicity, photoluminescence and excellent biocompatibility. ...
... Cd Pb Zn C 1 700 700 700 C 2 700 1100 1500 C 3 700 1500 700 C 4 700 1500 1500 C 5 1500 700 1100 C 6 1500 700 1500 C 7 1500 1500 700 C 8 1500 1500 1500 C 9 1100 1100 1100 C 10 1100 1100 1100 GR was linearly correlated with concentration of the Pb, Cd and Zn which will be used for developing multivariate calibration models. ...
Article
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In this work, we did our best to develop a novel and interesting analytical method based on coupling of spectrofluorimetry with first-order multivariate calibration techniques for simultaneous determination of lead (Pd), zinc (Zn) and cadmium (Cd) in HeLa cells. To achieve this goal, quenching of the emission of graphene (GR) was individually investigated in the presence of Pb, Zn and Cd and then, according to the linear ranges obtained from individual calibration graphs, a multivariate calibration model was developed based on modeling of the quenching of the emission of GR in the presence of the mixtures of Pb, Zn and Cd. First-order multivariate calibration models were constructed by partial least squares (PLS), principal component regression (PCR), orthogonal signal correction-PLS (OSC-PLS), continuum power regression (CPR), robust continuum regression (RCR) and partial robust M-regression (PRM) and their performances were evaluated and statistically compared. Finally, the OSC-PLS was chosen as the best model with the best practical performance for analytical purposes.
... Tis behavior may be associated with the formation of a protective layer that prevents the oxidation of titanium. Tis protection related to graphene flm has been observed by diferent authors concerning other metallic alloys such as copper alloys and steels [27]. ...
... Te deposition of graphene on metal surfaces forms a protective barrier that increases the corrosion resistance [27] and the dissolution process of diferent alloys. Te graphene deposition efciency against corrosion is on the order of 100 times higher than other processes. ...
Article
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Graphene and niobium oxide are used in biomaterial coatings. In this work, commercially pure titanium (cp Ti) was coated with graphene oxide (GO), niobium pentoxide (Nb2O5), and a mixture of both materials (NbGO) by the electrochemical deposition method. The surface morphology, roughness, wettability, and degradation of coated and uncoated samples were analyzed by scanning electron microscopy, interferometry, and contact angle. The results showed that the specimens coated with NbGO (cp Ti-NbGO) showed the highest surface roughness (Ra = 0.64 μm) and were hydrophobic. The contact (θ) angle between water and the surface of uncoated specimens (cp Ti), coated with GO (cp Ti-GO), coated with a mixture with GO and Nb2O5) (cp Ti-NbGO), and coated with Nb2O5 were 50.74°, 44.35°, 55.86°, and 100.35°, respectively. The electrochemical corrosion tests showed that coating with graphene oxide increased the corrosion resistance and coating with Nb2O5 decreased the corrosion resistance. The negative effect of the effect of Nb2O5 coating in corrosion resistance compensated for the release of Nb2O5, which helps osseointegration, increasing cell viability, and proliferation of osteoblasts. The NbGO coating may be a good way to combine the bactericidal effect of graphene oxide with the osseointegration effect of Nb2O5.
... Materials made by MEMS [22] are difficult to meet the performance requirements in some special environments, such as acid, alkali and high temperature. Relative to other adulterants, the honeycombed twodimensional network structure of graphene [23][24][25][26] provides it with excellent potential barriers and shielding properties [27][28][29][30][31] which can inhibit the passage of corrosive media and significantly lengthen the diffusion path of the corrosive solution, thus enhancing the corrosion performance of microparts. ...
Article
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Nickel-based microparts possess a short lifetime owing to their rapid dissolution in corrosive environments. To mitigate this phenomenon, composite microparts of graphene/Ni were prepared using UV-LIGA technology; their corrosion behavior was examined in acid, alkali, and salt solutions as well as after subjecting them to heat-treatment processes. The microstructures were investigated with scanning electron microscopy (SEM), X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). Corrosion resistances were characterized through various electrochemical tests and compared with those of pure Ni microparts. The results demonstrate that the surface oxidation layer (i.e.,the protective layer) of the microparts was readily destroyed in NaCl and H2SO4 solutions without the formation of a passivation film; however, a passivation film was formed in the NaOH solution. The corrosion rates of graphene/Ni in NaCl, NaOH, and H2SO4 corrosion solutions were reduced by 73%, 22%, and 84%, respectively, relative to those of pure Ni microparts. This can be primarily attributed to the homogeneous dispersion of graphene in the Ni matrix, which refined the grain size, and the impermeability and chemical stability of graphene, which lengthened the diffusion path of the corrosive medium. In addition, heat treatment of the graphene/Ni microparts at 200 °C increased the corrosion resistance by a factor of nearly one with little change in microhardness, which can be attributed to the removal of internal stress and the increased proportion of CSL grain boundares. Corrosion occurred at the interface between nickel and graphene, lengthening the corrosion path.
... Cette évolution des résistances Rf, RD et Rt observée dans le cas du graphène pourrait donner des explications de la bonne efficacité de protection contre la corrosion des couches hybrides GNs@ppHMDSO. Comme le montre le schéma de la figure IV.13, les feuilles de graphène présents dans la couche ppHMDSO pourraient former une barrière supplémentaire à la diffusion des espèces du milieu corrosif vers la surface métallique et renforcent ainsi les performances anticorrosion du revêtement[127]. IV.13 : Mécanisme de protection des couches de ppHMDSO et GNs@ppHMDSO. ...
Thesis
Dans cette thèse, des couches minces nanocomposites à base de graphène ont été élaborées pour la première fois par plasma atmosphérique hors équilibre pour améliorer les propriétés de résistance à la corrosion de l’acier au carbone E24 et de l’aluminium 2024. Une stratégie spécifique a été mise en œuvre et consiste à atomiser une suspension colloïdale polymérisable via un nébuliseur dans la zone de décharge plasma pour obtenir en une seule étape des couches nanocomposites. Deux types de décharge plasma ont été étudiées, une décharge à barrière diélectrique (DBD) et un jet de plasma (APPJ), pour la croissance de couche nanocomposites à matrice organosilicié à partir d’une solution colloïdale obtenue par dispersion de feuillets de graphène dans une solution d’hexaméthyldisiloxane (HMDSO). Les revêtements ont été caractérisés par MEB, FTIR, XPS et Raman en fonction des paramètres de la décharge plasma tels que la puissance, les débits de gaz plasmagène et de monomère et le temps de traitement. Les analyses montrent une dispersion homogène des feuillets de graphène dans la matrice polymère, et les dépôts obtenus par DBD sont moins poreux et ont un caractère plus organique que ceux obtenus par APPJ. Les propriétés anticorrosion des nanocomposites ont été évaluées par spectroscopie d’impédance électrochimique et mettent en évidence l’augmentation de l’effet protecteur contre la corrosion, avec une augmentation jusqu’à 3 ordres de grandeur de la résistance au transfert de charge sur l’acier traité. Les résultats obtenu dans cette thèse permettent de démontrer que l’incorporation de feuillets de graphène dans la matrice de polymère plasma a pour effet de diminuer la porosité des couches, d’augmenter la résistance à la corrosion, et d’améliorer également la dureté et le module élastique des nanocomposites ce qui constitue un aspect important pour les applications industrielles.
... Graphene oxide (GO) shows promise as an eco-friendly additive in different types of coating to improve their protective properties against corrosion [1,2]. By using the incorporation of GO to organic [3][4][5][6], metallic [7][8][9][10] and inorganic non-metallic coatings [11], researchers have created composite coatings with higher levels of anticorrosion properties. ...
Article
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Graphene oxide (GO) is an advanced additive improving the properties of various types of coatings and intensifying the deposition process. In this work, GO is used as an additive to the traditional phosphating solution of the widely used Russian low-carbon steel 08YU (DC04). The anticorrosion properties of the obtained phosphate coatings were investigated in neutral (0.5 M NaCl) and acidified (0.1 M Na2SO4 + 0.02 M H2SO4) aqueous solutions. Increasing the GO concentration in the phosphating solution to 0.3 g/L was found to improve the anticorrosion properties of the phosphate coatings in neutral NaCl solutions. At the same time, in acidified Na2SO4 solutions, the corrosion rate of 08YU steel with phosphate coatings increased as a function of the GO concentration. It is assumed that a possible reason for various corrosive behavior is the influence of the GO plates distributed in the coating on the rate of the oxygen or hydrogen reduction reactions.
... Graphene is the strongest substance that has ever been found. It has a Young's modulus of 1 Terapascal (TPa) and tensile strength of 130 Gigapascal (GPa)[54] [55]. Graphene also possess has electric conductivity as high as 6×10 5 S/m [56], thermal conductivity of approximately 3000 to 5000 W/m.K [57], high electron mobility 200,00 cm 2 /V.s [58]. ...
Preprint
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Protection of metal is primary undertaking for any design engineer and coating formulator. Construction of large scale equipment and structure involves huge investment in terms of money, time, manpower and other resources. In economic aspects, the life of such structure must as long as possible to get the best return on its investment. To improve the life of such huge structures, it is becomes mandatory to protect the metal substrates from corrosion. Application of corrosion resistant coating is one of the most intriguing, robust, practical and efficient techniques to safeguard the metal from corrosion. Graphene is novel material and got prodigious application due to its extraordinary features. Lot of research has been conducted since last decade for modifying the graphene and making the best use to formulate corrosion resistant coating. The use of graphene in the coating creates an obstacle and increases the convoluted path for corrosive medium to reach the metal. As the path to reach to metal is increased, it delays the corrosion medium to reach up to the metal and thus corrosion of metal can be avoided. In this literature review is conducted for various aspects of corrosion, importance of graphene in coating formulation is discussed, which includes chemical modifications of graphene, effect of graphene concentration on corrosion inhibition and contact angle of coating. This review also discussed about the importance of water based corrosion resistant coating to avoid the environmental damages. Keywords: Graphene, Corrosion resistance, contact angle, water base coating, metal protection, corrosive media, corrosion inhibition.
... It can prolong the penetration path of destructive elements into the coatings and metal substrates [2]. Layered double hydroxides (LDHs) [3], metal-organic frameworks (MOFs) [4], covalent organic frameworks (COFs) [5], graphene oxide (GO) [6], hexanol boron nitrate (h-BN) [7], transition metal dichalcogenides (TMDs) [8,9], and transition metal carbides/nitrides (MXenes) [10] are some of the well-known 2D materials which are widely utilized in various fields, especially in corrosion protection. GO possesses many exceptional features like a single layer, large surface area, and outstanding chemical and mechanical characteristics. ...
Article
Corrosion is a natural process between a metal and its environment that can gradually cause catastrophic damage to the metal equipment, which would have economic implications. Consequently, several protective methods have been utilized to prevent metals from severe degradation. Organic polymeric coatings have been widely used as the most convenient and cost-effective method to boost metals' anti-corrosion properties. Nonetheless, these coatings have a significant amount of solvent, resulting in shrinkage and micro defects in the films during the curing process. Many studies have verified that transition metal carbides/nitrides (MXenes) can form a “labyrinth effect” in the polymeric coatings due to their “nano-barrier effect”. Furthermore, based on their sheet-like structures, they can considerably cover the surface defects of the polymeric films. Therefore, the penetration of corrosive elements can be substantially curbed. It is the first review that specifically focused on the new family of 2D nanomaterials, i.e., MXenes, and discussed their applications in corrosion protection systems. The MXenes' pros and cons in the polymeric matrixes as nanofillers will be clarified. Moreover, the synthesis and functionalization methods of the MXenes, their applications, and corrosion protection mechanism will be explored. Subsequently, the MXenes' superiority over other 2D nanomaterials has been highlighted while their future perspectives and industrial applications have been predicted.
... Lubricating tribochemical layers have been found on sliding areas of retrieved long-lasting, functioning metal on metal (MoM) hip prostheses which in their turn have also extended the lifespan of the prosthesis. The tribochemical layers, consisting of nanocrystalline graphite and amorphous sp2 carbon [3] supports the strategy of modifying the prosthetic metallic surface with organic coatings, especially with graphene-based materials, due to their exceptional properties as a solid lubricant [4,5] and their diffusion barrier effect as anti-corrosive coating [6], so, making graphene an ideal candidate for the modification of metal surfaces. ...
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Improvements in durable lubrication together with minimized wear are essential for obtaining long-term, functioning metallic joint prostheses. To achieve this objective, CoCr surface was functionalized with Graphene Oxide (GO) and characterized by FTIR and XPS. CoCr alloy was subjected to alkalinization in order to generate high hydroxyl content on the surface. FTIR and XPS revealed reactive OH groups, enabling intermediate coupling via (3-aminopropyl) triethoxysilane (APTES), which was cured at 45 °C and 75 °C for 24 h and 30 min, respectively. FTIR revealed cross-linked films (Si–O–Si), inferring condensation and self-assembly of silane layers, while XPS revealed the presence of NH2, enabling chemical binding of GO. Silane-coated CoCr disks were immersed in GO solution at 60 °C for 12h and 24h, respectively. FTIR displayed CC band confirming the assembly of GO on silane-coated CoCr surfaces. XPS revealed three possible surface mechanisms: (1) reaction between primary amines of APTES and epoxy groups of GO; (2) free –OH groups in APTES and carboxyl groups in GO; and (3) reaction between APTES primary amines and –OH from carboxyl groups of GO. Overall, the multilayer system CoCr–OH–Si45-GO24h showed covalent functionalization of metal substrate with GO to a large extension of surface area among all the multilayer systems studied.
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In a quest for smart coatings, a novel multi-level active/barrier composite coating was developed. For this aim, the polyaniline grafted graphene oxide nano-sheets were decorated with ZIF-9 type metal-organic framework (MOF). The GO sheets incorporation into the polymeric coating could promote its barrier effect against corrosive agents. Also, the polyaniline-reduced GO sheets provide proper dispersion and better barrier protection than the neat GO. On the other hand, the polyaniline creates an oxide-based passive layer on the metal surface, and besides it reproduces itself through redox reactions. Self-healing is also achievable through rGO decoration with pH-responsive ZIF-9 particles which release inhibitive Co (II) cations and benzimidazole molecules. The fabricated nanostructures' synthesis successfulness was checked via FT-IR, XRD, Raman, ICP, SEM, Zeta potential, and UV-Vis techniques. The ICP as well as solution (NaCl) phase electrochemical analyses achievements confirmed the [email protected] nano-hybrid pH-sensitive properties with outstanding control release potency with a total resistance of 7430 Ω.cm² (inhibition efficiency: 80%). After revealing the anticorrosion impact of [email protected] in saline solution, the particles were incorporated into the epoxy coating (EC) for further analysis. Records clarified that the inclusion of [email protected] nano-hybrid into the scratched epoxy coating resulted in 120066 Ω.cm² (inhibition efficiency:84%) in the best situation, evidencing the unique shelf-healing performance of the coating. Simultaneously, the electrochemical studies were applied to the intact coatings and the results declared that the film resistivity of [email protected]/EC reached around 16 GΩ.cm². Besides the delamination and destruction indexes descended to 10% and 36%, respectively.
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Effect of graphene oxide on the corrosion behavior of electrodeposited Cu–Cr coatings on mild steel substrate was studied and the results were correlated with the texture of the coatings using electron backscattered diffraction. The graphene oxide (GO) prepared using modified Hummer’s method was added in five different concentrations (50, 100, 150, 200, 250 mg/L, labelled as GO1, GO2, GO3, GO4, GO5 respectively) by dispersing the prepared GO in the aqueous electrolyte bath. The coatings obtained were found to be compact and without any cracks. The corrosion behavior was studied using potentiodynamic polarization and electrochemical impedance spectroscopy. It was found that with the addition of GO, the corrosion resistance increased significantly compared to the pristine CuCr until the 150 mg/L of GO addition and thereafter it again started to decrease. The corrosion current density obtained for pristine CuCr, CuCr-GO1, CuCr-GO2, CuCr-GO3, CuCr-GO4, CuCr-GO5 was 9.2, 7, 5.4, 4.6, 8.3, and 10.7 μA/cm2 respectively. GO3 was found to have the lowest icorr which corresponds to highest corrosion resistance. There was a 50 pct reduction in the value of icorr by the addition of 150 mg/L of graphene oxide (GO3) compared to pristine CuCr coating. Electron backscattered diffraction analysis revealed a high fraction of low angle grain boundaries (LAGB’s), a preferred texture along low energy (111) and (311) planes in case of CuCr-GO3 compared to high energy (101) planes for pristine CuCr. The fraction of LAGB’s for pristine CuCr, CuCr-GO3, CuCr-GO5 were found to be 0.21, 0.36, and 0.28, respectively.
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Various Mn-Cr co-doped titanium dioxide nanotubes (Mn/Cr-TNs) have been prepared on titanium plates through electrochemical anodization. The crystal structure, morphology, and composition of the samples prepared as well as their photoelectrochemical (PEC) performance on a typical 403 stainless steel (403SS) have been studied and discussed. Based on the XRD results, all the samples prepared only include anatase phase. In addition, SEM analysis showed that the doping or co-doping of manganese and chromium does not change the surface morphology of the samples. The samples show a clear red-shift of the optical edge and enhanced visible light absorption. Furthermore, improved photocurrent density and photovoltage are shown by Mn/Cr-TNs under light irradiation, according to the PEC tests. Upon intermittent light illumination, the open circuit potential of the coupled 403SS is shifted to −600 mV with a potential drop of 340 mV relative to the corrosion potential of steel (−260 mV) by sample Mn1 (as the best co-doped photoanode), which suggests a good photocathodic protection (PCP) performance. The photocathodic protection potential is further increased and stabilized at −620 mV for 1 h in the durability test under continuous illumination. Mn1 showed the highest PEC activity under light irradiation. Mn/Cr-TNs have higher activity compared with undoped and Mn or Cr-doped titanium dioxide nanotubes (TNs) due to the synergetic effect of Mn and Cr.
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Polymer coating modified with graphene oxide (GO) and duplex electroless Nickel-Phosphorus (Ni-P) with polytetrafluoroethylene (PTFE) coating were investigated for their corrosion behaviour in simulated high-temperature geothermal environments with/without H2S and CO2 gases for geothermal applications. The polymer coating with added GO nanosheets demonstrated low wetting ability and suppressed corrosion effects of the substrate at 120 °C. The Ni-P/PTFE duplex coating with the lowest P content was suitable in an H2O liquid environment at 120 °C while high P was more promising in the two-phase CO2/H2S environment. Nevertheless, all the coatings were unprotective and allowed substrate corrosion at 250 °C in the H2S/CO2 environment.
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Mo-doped, Cr-doped, and Mo-Cr co-doped titania nanotube arrays were synthesized through the single step anodization of titanium. Mo-Cr co-doped titania nanotubes prepared showed great improvement on photocatalytic activity in the protection of stainless steel (403SS) under visible light irradiation compared with Mo and Cr mono-doped titania. The open-circuit potential (OCP) of 403SS (in 3.5 wt.% aqueous NaCl) coupled with the best co-doped sample (Cr50:Mo50-TNT) was reduced from -240 to -690 mV, while the electrode potential was maintained at -320 mV even upon turning the light off. This study also identified the effect of the addition of sulfur compounds as hole scavengers on the photoelectrochemical (PEC) properties and photoelectrochemical cathodic protection (PCP) by the best Mo-Cr co-doped titania nanotube. Sodium sulfate and sulfite, sodium thiosulfate, sodium sulfide, potassium metabisulfite and thiourea have been used as hole scavengers. The order of photocurrent is as follows: Na2S > K2S2O5 > CS(NH2)2 > Na2S2O3 > no hole scavengers > Na2SO4 > Na2SO3. Mo-Cr co-doped titania nanotube show much more favorable PCP impact on 403SS than the pure titania sample, according to the results of the changes in the potentials and current densities. Furthermore, the results finally proved that sodium sulfide is the most appropriate hole scavenger.
Article
Graphene oxide has aroused significant interest for a range of applications owing to their outstanding physico-chemical properties. Specifically, the presence of a large number of reactive chemical moieties such as hydroxyl, carboxyl, epoxide, and sp2 carbon allows these novel materials to be tailored with additional functionalities with the purpose of tuning intrinsic properties. There has been a vivid discussion on the non-covalent modification of GO; however, a comprehensive summary of the chemical functionalization which enables forming a stable particle is still elusive. Hence, in this study, we summarize recently advanced methodologies used for designing the functional GO for their use in specific applications. Together with a brief discussion on the essential characterization techniques, this study will provide fundamental insight into the latest developments in the preparation of covalently modified GO derivatives, thereby leading to their broader utilization in future.
Article
Conventional metal matrix composites (MMCs) with particles, whiskers, and fibers as reinforcements have been developed primarily for structural applications. Despite their long history of progress, however, MMCs exhibit sluggish performance enhancements. Low-dimensional nanomaterials, such as carbon nanotubes, graphene, boron nitride nanotubes, boron nitride nanosheets, MXene, and metal dichalcogenides, have emerged as effective nano-sized fillers for developing metal matrix nanocomposites (MMNCs) to overcome the performance limitations of conventional materials. Although various low-dimensional nanomaterial fillers have been considered as promising candidates for enhancing the multifunctional performance of MMNCs, structural properties of MMNCs filled with 1-D or 2-D nanomaterials have been a major area of research. Taking advantage of the unique properties of low-dimensional nanomaterials, multifunctional MMNCs have exhibited a remarkable trend in the development of advanced materials to meet the complex demands of emerging application areas. In this review, the current state of recent research in the field of 1-D and 2-D nanomaterial-filled MMNCs is discussed. Additionally, we have examined a vast array of fabrication processes for tailoring the microstructures and interfaces of MMNCs. Moreover, discussions on the structural and functional properties, applications, challenges, and future prospects of multifunctional MMNCs filled with low-dimensional nanomaterials have also been presented.
Article
Layered double hydroxide (LDH) coating fails to provide stable anti-corrosion ability and anti-biofouling performance on metals. In this work, by exploiting the 2D graphene oxide and silane molecular, an eco-friendly and facile electrodeposition strategy for preparation of fluoride-free superhydrophobic coating (LDH-GO/DTMS) is developed, in which the aforementioned challenges can be addressed. Electrochemical test and bovine serum albumin (BSA) adsorption experiment of the LDH-GO/DTMS coating are investigated. As results, LDH-GO/DTMS coating exhibits a high protection efficiency (99.98 ± 0.10 %) and corrosion current density (Icorr) decreases by ~4 orders of magnitude compared to bare Al alloy. The adsorption content of BSA on the coating decreases by ~9-fold compared to bare Al alloy. Furthermore, impedance modulus at 0.01 Hz (|Z|0.01 Hz) of the composite coating (4.05 ± 0.05 MΩ·cm²) is still ~2 orders of magnitude higher than Al alloy after immersion in 3.5 wt% NaCl solution over 30 days. The special wettability, physical barrier and the labyrinth effect endow the coating with good anti-corrosion and anti-biofouling property. This eco-friendly and fluorine-free strategy provides new insights for developing anti-corrosive and anti-biofouling coatings on metals used in marine environment.
Article
The present work reports the effect of adding Graphene Oxide (GO) and reduced Graphene Oxide (rGO) in the corrosion protection provided by a water-borne resin applied on a galvanized steel substrate. Three concentrations, 0.05, 0.1 and 0.15 (all wt%) were tested. The results were markedly affected not only by the concentration of particles but also by their nature. Although the zeta potential values suggested good dispersibility of the particles in the resin, certain aggregation was observed, mainly in rGO 0.1 wt% and rGO 0.15 wt% formulations. The electrochemical impedance spectroscopy (EIS) technique characterised the free films' transport properties. The results suggested that the aggregation strongly influenced the film morphology. The rGO 0.1 wt% and rGO 0.15 wt% formulations exhibited percolating pores that facilitated the electrolyte uptake through the films. The EIS technique was also used to study the protective performance of the films when applied to the metallic substrate. The results confirmed the harmful effect of the particle's aggregation. The results were interesting for the rGO 0.05 wt% system, which displayed long-lasting protection properties. This performance was explained considering its good barrier properties and the zinc surface passivation by the generation of zincite, ZnO.
Article
Molecular dynamics (MD) simulations are performed to study the repeated nanoindentation on aluminum (Al) substrate with different boron nitride nanosheet (BNNS) coating thickness. To reveal the strengthening mechanism of coating, the hardness, surface morphology, atomic stress, atomic strain and phase transition are analyzed. The results show that the hardness of substrate increases with the coating thickness. It is also revealed that the pressure area of Al substrate increases with coating thickness. Because of the coating force, more atoms move along the loading direction, causing the substrate to slip more and more atoms to be severely strained. However, although severely deformed, some Al atoms still recover elastically after unloading. After multiple loadings, some elastic deformations are transformed into plastic deformations. The lattice structures are destroyed, possibly with amorphous atoms.
Article
Graphene is a two-dimensional carbon nanomaterial. It consists of a planar film composed of carbon atoms with sp2 hybrid orbitals, which is hexagonal and honeycomb in shape. The thickness of graphene is only 0.34 nm, and the unique two-dimensional lattice and electron structure of graphene also makes it possess excellent physical and chemical properties. When the traditional carbon material cannot detect some substances with very similar oxidation potential or some at ultra-trace level, the emergence of graphene replaces the traditional carbon material and provides the possibility for the preparation of biochemical sensors that can measure the above substances, which has a very broad development prospect. Based on the excellent properties of graphene, this paper starts from four common biochemical substances in daily life, including explosives, pesticides, pathogens and toxins and introduces the principle and effects of various biochemical sensors based on graphene and its composites for these four substances. Finally, the future development trend is prospected.
Article
The high aspect ratio and unique thermal and electrical characteristics of carbon nanofiber (CNF) made it an ideal physical barrier against the penetration of corrosive ions. However, the poor compatibility of the CNF with the polymer matrix and the lack of active corrosion inhibitors are the key limitations of this nanomaterial, resulting in short-term anti-corrosion resistance. An intelligent self-healing epoxy (EP) coating, including CNF modified with a polydopamine (PDA)−La 3+ complex, was successfully fabricated to overcome these issues. Electrochemical impedance spectroscopy (EIS) evaluation implied that mild steel (MS) submerged in a 3.5 wt % NaCl solution containing the CNF− PDA−La extract had a total corrosion resistance (R T) of 3107 Ω cm 2 after 24 h, which is much greater than the MS immersed in the blank solution (1378 Ω cm 2). Furthermore, the potentiodynamic polarization analysis indicated a 50% reduction in the corrosion rate (CR) of the MS soaked in the solution containing released PDA and La 3+ inhibitors compared to the blank solution. EIS and salt spray analysis were used to assess the self-healing capabilities of epoxy coatings incorporating modified CNFs. EIS assessment of scratched coatings revealed a 117% improvement in R T of the CNF−PDA−La/EP coating compared to the Blank/EP after 10 h of immersion in the saline solution. This enhancement is due to the intelligent release of PDA and La 3+ inhibitors at the scratch sites, which can mitigate MS corrosion by forming a PDA−Fe complex and the deposition of La(OH) 3 on the MS surface. The salt spray test results also exhibited the CNF−PDA−La/EP coating's superior anti-corrosion capabilities after 20 days. Hence, this research presents a logical approach for developing anti-corrosion coatings with improved nanofiller compatibility and self-healing characteristics.
Article
In this work, polyhedral oligomeric silsesquioxane (POSS) was covalently grafted on 2D covalent organic framework of TpPa-1 through Schiff base reaction (POSS-TpPa-1) to synergistically improve the corrosion and tribological resistance of epoxy coating. The results show that compared with the hydrophilic TpPa-1, POSS-TpPa-1 exhibits excellent hydrophobicity, and the water contact angle can reach 134°. Furthermore, POSS-TpPa-1 with different weight ratios was added into epoxy coating, and the anti-corrosion and wear resistance of the composite coatings were studied through electrochemical impedance spectroscopy (EIS) and friction and wear tests, respectively. The EIS results show that when the additive amount of POSS-TpPa-1 is 2 wt%, the impedance modulus in the low frequency region can maintain 1.04 × 10⁹ Ω·cm² even after being immersed in 3.5 wt% NaCl solution for 60 days, indicating its good anti-corrosion performance. The friction and wear experiments show that the epoxy composite coating with 2 wt% POSS-TpPa-1 exhibits the lowest friction coefficient of 0.23, suggesting that POSS-TpPa-1 can effectively improve the friction resistance of the coating under the premise of good dispersion. This work develops a new composite filler to simultaneously improve the anticorrosion and wear resistance of epoxy coating, which might be able to trigger further studies to develop more advanced composite coating by incorporating 2D-COF.
Article
Steel corrosion has been a major perpetual issue of concern for durability and structural integrity of steel and reinforced concrete infrastructure. Polymeric, zinc-galvanic and chromate conversion coatings are commonly applied to protect typical steel materials such as structural steel, reinforcing steel bar (rebar), mild steel and light gauge steel used in infrastructure. Yet, due to physical integrity, long-term performance and environmental concerns, their applications have been limited. In recent years, graphene has garnered considerable attention in the field of anti-corrosive coatings and substantial progress has been achieved in the development of particular graphene-based monolithic (single/few-layer graphene and graphene oxides) as well as laminate and nanocomposite coatings. Despite considerable efforts dedicated towards fundamental research, the laboratory to industry transition of graphene-based anti-corrosive coatings remains challenging. To this end, this report reviews the state-of-the-art on graphene-based coating technology with application to steel surfaces and discusses, both, experimental studies and theoretical aspects. Specifically, this review presents (i) production of different forms of graphene-based materials and the coating process; (ii) corrosion resistance and anti-corrosive coating performance of graphene-coated steel materials, (iii) key potential areas and challenges pertaining to the application of graphene-based coating to structural steel and rebar; and (iv) potential future directions towards corrosion protection and smart coatings.
Thesis
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O isolamento experimental do grafeno em 2004 foi um ponto de partida para o desenvolvimento de diversas pesquisas tratando deste material e seus derivados. Dentre as propostas de aplicação do grafeno, se encontrava a aplicação como reforço em materiais compósitos. A formulação de compósitos de matriz metálica com reforço de grafeno inspirou o desenvolvimento de pesquisas sobre adição de grafeno em eletrodos consumíveis para soldagem, as quais começaram a ser publicadas em 2014. De 2014 ao presente poucos trabalhos de aplicação de grafeno e derivados tratavam da soldagem de aços. Neste contexto, o presente trabalho se propôs a desenvolver eletrodos revestidos com aplicação de óxido de grafeno para soldagem e avaliar seu efeito na microestrutura, propriedades mecânicas e resistência à corrosão das juntas soldadas. Óxido de grafeno foi sintetizado pelo método de Hummers e Offeman e aplicado em eletrodos E6013 comerciais por imersão em solução de 5,5 g/L do óxido em álcool etílico. Ensaios de difração de raios-X confirmaram a eficácia da síntese de óxido de grafeno e indicaram que o produto de síntese continha número médio de camadas de aproximadamente 14. Corpos de provas soldados e cordões depositados sobre chapa foram realizados. A adição de óxido de grafeno causou alteração no comportamento do arco durante a soldagem, evidenciada pela maior formação de respingos. A análise microestrutural indicou que a solda com adição de grafeno, se comparada com a solda do eletrodo convencional, apresentou ligeiro aumento na formação de microconstituintes que demandam taxa de resfriamento mais rápida, como ferrita de contorno de grão. O menor grau de refinamento da microestrutura da zona termicamente afetada da solda com adição de grafeno resultou em redução da microdureza na vizinhança da solda. As propriedades mecânicas aferidas em ensaio de tração das juntas soldadas foram compatíveis, indicando que a adição de grafeno não desqualifica a padronização E6013 do eletrodo testado. Ensaios de polarização potenciodinâmica indicaram que a adição de óxido de grafeno diminuiu a taxa de corrosão cerca de 30 vezes em relação às juntas obtidas com eletrodo E6013 convencional.
Article
Enhancement of the biological and mechanical properties of dental metals is important for accommodation with therapeutic schemes in different stomatological disciplines. Nanocoatings based on graphene family nanomaterials (GFNs) improve the topological structure and physicochemical properties of metal surfaces, endowing them with new properties while maintaining inherent mechanical properties. Nano-composite coatings, composed of GFNs with one or more type of polymer, metal, oxide, and inorganic nonmetallic compound, offer more matching modification schemes to meet multifunctional oral treatment requirements (e.g., anti-bacterial and anti-corrosive activity, osteogenesis and angiogenesis). This review describes recent progress in the development of GFN composite nanocoatings for the modification of dental metals, focus on biological effects in clinical settings. Underlying molecular mechanisms, critical modification schemes, and technical innovation in preparation methods are also discussed. The key parameters of GFN composite nanocoating surface modification are summarized according to effects on cellular responses and antibacterial activity. This review provides a theoretical reference for the optimization of the biological effects and application of GFN composite nanocoatings for dental metals, and the promotion of the environmentally friendly large-scale production of high-quality multifunctional GFN-based nanocoatings in the field of oral science.
Chapter
Graphene has an incredible wealth of optical and electrical properties. In addition to durability, robustness, and environmental resilience, graphene has high mobility and optical transparency. To date, theoretical physics and electronic systems have been a big priority. However, we assume its true potential lies within photonics and optoelectronics, even in the absence of a complete image of its characteristics, the combination of its unique optical and electronic properties can be thoroughly utilized. In this chapter, we present a comprehensive review of recent developments in graphene-based devices. Light emissions from graphene-based devices have been evaluated with different aspects, such as thermal emission, electroluminescence, and plasmons-assisted emission. Theoretical investigations and experimental demonstrations in the development of graphene-based devices have also been reviewed and discussed. Finally, this review comprehensively discusses current technological issues and challenges related to the potential applications of emerging graphene-based devices such as photodiodes, solar cells, and light-emitting diodes.
Article
Compared with graphite products, graphene-assembled dense monoliths have superior mechanical, electrical, and thermal properties and show better performance in energy-related applications. However, current liquid or solid assembly methods have their own disadvantages resulting in a trade-off between dimensions and properties. Herein, inspired by ceramics technology, a direct annealing method based on graphene oxide (GO) ionic putties is developed to prepare graphene-based monoliths with both arbitrary shapes and high performance. The GO ionic putty is prepared by a vacuum rotary evaporation method from GO/ionic liquid aqueous dispersions in which the GO sheet sizes and contents are arbitrarily tunable, showing better scalability than traditional methods relying on high shear forces. The nonvolatile ionic solvent acts as the thermal medium and material precursor in the annealing process, which is different from that of the volatile solvents. Therefore, an optimal ionic putty with superior plasticity and ideal microstructure is obtained to endow the graphene-based monoliths with designable macrostructures and ultrahigh mechanical strength (190 MPa) and electrical conductivity (175 S cm⁻¹), showing good application promise in corrosion-resistant Joule heating. These superior properties are attributed to the dense and interlocking graphene network. This work provides a scalable and simple approach for high-performance graphene-based monoliths toward practical applications.
Article
A novel kind of graphene/polyaniline hybrid microcapsules loaded with self-healing agent (linseed oil, LO) were synthesized by Pickering emulsion template method in this work. In our strategy, graphene oxide (GO) was used as Pickering emulsifier to stabilize emulsion droplet containing aniline and linseed oil. After the polymerization of aniline, graphene/polyaniline microcapsules loaded with linseed oil ([email protected]/PANI) were prepared. By adjusting GO concentration, oil-water ratio and emulsification rate, the size of the emulsion droplet and [email protected]/PANI microcapsule can be controlled at about 15-20 μm. The successful synthesis of [email protected]/PANI microcapsules was proved by SEM, FT-IR and TGA. The unique GO/PANI hybrid shell combined the outstanding barrier property of GO and anti-corrosion function of PANI. The solvent resistance results showed that the as-prepared microcapsules possessed stronger resistance to organic solvents. A smart coating with dual functions of anti-corrosion and self-healing was prepared by dispersing the as-prepared [email protected]/PANI microcapsule in waterborne epoxy resin. As the contents of microcapsules was 10 wt%, the scratch of the coating was completely healed after 12 h observed from the microscope images. The electrochemical impedance spectroscopy (EIS) and salt spray test all verified that the incorporation of microcapsules could significantly improve the anti-corrosion performance of the water-borne coatings. After 40 days' immersion, the low frequency modulus of the composite coating was almost 2 orders of magnitude higher than that of pure epoxy coating, and no obvious corrosion product was observed after 500 h salt spray test.
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In the proton exchange membrane fuel cells, the bipolar plates (BPs) are being widely used in multifunctional mode. They have many unique properties, including prevention of coolant and gas leakages, dissipation of heat from active portions, distribution of air, gas, and fuel uniformly, electric current conduction between cell to cell as a chain, etc. This experimental work was intense to fabricate polymer‐based composite bipolar plates using hybrid combinations. Composites are prepared by using carbon black (CB), glass fiber (GF), and graphite (G) with epoxy and silicone resins. The mixing of composite materials with resins is controlled by the Aquila Taguchi optimization (ATO) method through the L16 Orthogonal Array (OA). Mixing parameters are chosen as rotational speed (20, 30, 40, and 50 rpm), mixing time (10, 15, 20, and 25 min), and mixing temperature (25, 30, 35, and 40°C). Influencing these parameters increases the electrical conductivity (S/cm) and flexural strength (MPa) of the newly prepared bipolar plate composites. From this analysis, highest electrical conductivity is obtained, such as 268.361 S/cm. Similarly, extreme flexural strength occurred at 134.90 MPa.
Article
Owing to the variety of industrial applications of anti-corrosion coatings, the use of graphene-based technologies for improving the anti-corrosion performance of the coatings has become a hot topic for research. Composite coatings with smart dual-action can be gained by simultaneous GO nanosheets reduction/functionalization via corrosion inhibiting materials. This research focused on a green/affordable route for GO reduction/functionalizing by Golpar leaf (RFGO-GLE) extract molecules. With the aim of boosting the active protection performance of RFGO-GLE, this nanosheet was modified by Zn ions (RFGO-GLE@Zn). The EIS outcomes of the solution phase study revealed that the RFGO-GLE@Zn nano-layers inclusion (at 1000 ppm) into a seawater solution resulted in almost 80 % inhibition degree, confirming the release of protective agents. The morphological assessments of the scratched zone of the coatings revealed that the inhibitive chemicals were released as soon as mechanical damage produced on the coating. The EIS results of the samples with artificial scratches represented that the total resistance improved with each step of modification, indicating the self-heal ability of the designed nanosheets. To scrutinize the composites barrier properties, the EIS was applied for the intact coatings, and the records manifested that the RFGO-GLE and RFGO-GLE@Zn nanosheets could significantly raise the total resistance in initial stages. Besides, the evaluations revealed that the total resistance of neat EP coating failed during 3 weeks, while, the RFGO-GLE@Zn/EP resisted even up to 7 weeks.
Article
Graphene and its derivatives have attracted much interest as corrosion-resistant coatings for magnesium alloys since 2014, when the first reports appeared in the literature. The interest in the use of such carbonaceous compounds to protect magnesium and its alloys from corrosion relies on a set of attributes such as chemical inertness, and high surface area. To support the development of optimized graphene-based films it is imperative to expand the current knowledge toward a deeper understanding of corrosion mechanisms and their interaction with practical aspects related to coating deposition and morphology. In the present work, graphene-based coatings for magnesium alloys are reviewed. We explored the correlation between coating architecture, deposition methods and materials selection using the Ashby approach. The results of the materials selection process revealed that composite coatings consisting of an inorganic matrix obtained by plasma electrolytic oxidation of magnesium alloys and graphene oxide nanosheets as blocking agents can provide surfaces with high corrosion resistance in sodium chloride solution. For biomedical applications, composite coatings consisting of a mixture of organic matrices such as chitosan and graphene oxide as reinforcing particles are attractive candidates. The results are discussed based on coating architecture and its interplay with the corrosion properties.
Article
β-Cyclodextrin-based compounds are used to develop and innovate materials that protect against corrosion due to their sustainability, low cost, environmental friendliness, excellent water solubility and high inhibition efficiency. However, corrosion potentials of β-CD-based compounds were not reviewed with the modern trends. The essence of the problem is that a deep understanding of the development and innovation of β-CD-based compounds as corrosion inhibitors is very important in creating next-generation materials for corrosion protection. In this review, the fundamental behaviour, importance, developments and innovations of β-CD modified with natural and synthetic polymers, β-CD grafted with the organic compounds, β-CD-based supramolecular (host-guest) systems with organic molecules, polymer β-CD-based supramolecular (host-guest) systems, β-CD-based graphene oxide materials, β-CD-based nanoparticle materials and β-CD-based nanocarriers as corrosion inhibitors for various metals were reviewed and discussed with recent research works as examples. In addition, the corrosion inhibition of β-CD-based compounds for biocorrosion, microbial corrosion and biofouling was reviewed. It was found that (i) these compounds are sustainable, inexpensive, environmentally friendly, and highly water-soluble and have high inhibition efficiency; (ii) the molecular structure of β-CD makes it an excellent molecular container for corrosion inhibitors compounds; (iii) the β-CD is excellent core to develop the next generation of corrosion inhibitors. It is recommended that (i) β-CD compounds would be synthesized by green methods, such as using biological sustainable catalysts and green solvents, green methods include irradiation or heating, energy-efficient microwave irradiation, mechanochemical mixing, solid-state reactions, hydrothermal reactions and multicomponent reactions; (ii) this review will be helpful in creating, enhancing and innovating the next green and efficient materials for future corrosion protection in high-impact industries.
Article
Present work addresses the synthesis of different structural forms of polyaniline (PANI) and their nanocomposites with graphene as functional fillers to epoxy coating for minimizing mild steel corrosion. The π-π interactions between p-phenylenediamine functionalized graphene (fGO) and aromatic rings of in-situ grown covalently linked PANI on fGO facilitated the interfacial wrapping of graphene skeleton by PANI. The chemical, morphological, crystalline, and structural features of fGO-PANI nanocomposites are probed by FTIR, NMR, Raman, XPS, XRD, SEM, and HRTEM analyses. The emeraldine salt form of PANI (PANI-ES) exhibited significantly higher impedance and better corrosion inhibition properties than the emeraldine base (PANI-EB). Graphene skeleton in the fGO-PANI nanocomposite notably enhanced the anticorrosive properties of PANI with a multifold increase in total impedance. The 2D graphene skeleton in fGO-PANI nanocomposites provides excellent surface coverage as a structural barrier and increases the number of possible electron transfer pathways. Moreover, the oxidoreduction properties of PANI make the fGO-PANI-ES nanocomposite highly effective in increasing the impedance by multifolds. The corrosion protective mechanism of fGO-PANI-ES is discussed by emphasizing the role of graphene, different structural forms of PANI, and the dosing of graphene in fGO-PANI nanocomposites. The present work revealed fGO-PANI-ES as a promising material for new generation coatings to mitigate mild steel corrosion, particularly in a maritime environment.
Article
Organic–inorganic hybrid coatings (OIHCs) for corrosion protection represent a very important class of organic–inorganic hybrid materials. It has attracted much attention recently due to people’s awareness of environmental friendliness. The OIHCs display various advantages compared to pure organic or inorganic coatings, such as low volatile organic content (VOC), good anti-corrosion and adhesion properties on metal substrate. Here, a series of OIHCs have been prepared by using titanium tetraisopropanolate (TTIP) as the titanium source and glycidyl ether oxypropyl trimethoxysilane (GPTMS) as the coupling reagent. The amount of GPTMS used for the preparation have been adjusted and the corrosion protection performance has been studied. A high corrosion efficiency of 99.3% is achieved of the hybrid coatings on Cu substrates.
Article
Vinyl ester (VE) based nanocomposite coatings, loaded with an optimum content of silica aerogels, were fabricated on aluminum. Different graphene contents (1, 2, and 3% w/w) were applied via one-step and two-step spraying methods. Surface properties exhibited pronounced changes for the two-step coatings but remained nearly unchanged for the one-step coatings. Graphene was localized in the bulk of one-step coatings whereas the two-step method led to the aggregation of graphene nanoplatelets on the coating surface. Depending on the graphene content, small stacks (2 μm) to large agglomerations (20 μm) were detected on the surface of two-step coatings. The water contact angle was essentially increased from 61° for the pure VE coating to 96° and 115° upon the incorporation of silica aerogel and induction of an individual graphene layer, respectively. Such enhanced hydrophobicity was the major reason for the improved corrosion protection properties as found by Tafel polarization plots. The maximum protection efficiency was obtained for the two-step coating loaded by 2% graphene (η=99.5%). In conclusion, vinyl ester resin was found to be a great candidate for applications where high-performance coatings with improved corrosion resistance are needed. Moreover, the use of graphene, as an individual layer on the coating surface, and the utilization of silica aerogel, as a corrosion protective additive, were demonstrated to be a promising approach in real-life corrosion protection applications.
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In recent years, graphene has been widely employed in the field of metal corrosion protection owing to its outstanding impermeability and chemical stability, with examples of such metal protection including pure graphene coatings and graphene-based composite coatings. But the conductive graphene could promote the electrochemical reaction at the interface and accelerate the corrosion of metal substrates. More emerging graphene-like 2D nanosheets are attracting research attention for the application of metal anticorrosion, because of their barrier properties and poor conductivity, mainly including boron nitride (BN), molybdenum disulfide (MoS2), zirconium phosphate (ZrP), and titanium carbide (MXene). In this review, the application of these graphene-like 2D nanosheets to metal protection is comprehensively reviewed. First, the general preparation methods of 2D nanosheets are briefly introduced. Second, surface functionalization of 2D nanosheets, including covalent and non-covalent modification, is described in detail. Third, the anticorrosion performance and optimization measures of pure 2D nanosheets coatings are summarized. Next, the protection performance, anticorrosive mechanism, and optimizations of 2D nanosheets composite coatings are presented. Finally, the future development of 2D nanosheets-based anticorrosive coatings has been prospected, and the challenges in the industrial application are discussed.
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Extreme environments represent numerous harsh environmental conditions, such as temperature, pressure, corrosion and radiation. The tolerance of applications in extreme environments exemplifies significant challenges to both materials and their structures. Given the superior mechanical strength, electrical conductivity, thermal stability and chemical stability of nanocarbon materials, such as carbon nanotubes (CNTs) and graphene, they have been widely investigated as base materials for extreme environmental applications and have shown numerous breakthroughs in the fields of wide‐temperature structural‐material construction, low‐temperature energy storage, underwater sensing and electronics operated at high temperatures. This review will examine the critical aspects of structural design and fabrication of nanocarbon materials for extreme environments, which includes the description of the underlying mechanism supporting the performance of nanocarbon materials against extreme environments, the principles of structural design of nanocarbon materials for the optimization of extreme environmental performances, and the fabrication processes developed for the realization of specific extreme environmental applications. Finally, perspectives on how CNTs and graphene can further contribute to the development of extreme environmental applications are presented. This article is protected by copyright. All rights reserved
Article
Sodium molybdate (Na2MoO4) doped graphene oxide/polypyrrole nanocomposite (GO-PPy + Na2MoO4) was synthesized and considered as a multi-functional corrosion inhibitor container to be embedded into the epoxy coating. To ensure the decoration of GO surface by PPy nanoparticles and doping of molybdate ions into the GO-PPy structure, several analyses such as FT-IR, Raman, ICP-OES, zeta potential, FE-SEM/EDS, and TEM were used. The active-barrier anti-corrosion features of GO-PPy and GO-PPy + Na2MoO4 in 3.5 wt% NaCl solution were screened by EIS, salt spray, pull-off, and cathodic disbanding tests. Potentiodynamic polarization analyses showed 77% inhibition efficiency in the solution containing GO+PPy + Na2MoO4 compared to the blank solution. The GO-PPy + Na2MoO4 reinforced epoxy coating exhibited the highest impedance (log ׀Z׀ 10 mHz = 10.58 Ω·cm², after 63 days) and the lowest delamination values (3.58%, after 63 days) in comparison with the pure epoxy coating (EP) (log ׀Z׀ 10 mHz = 6.1 Ω·cm² and delamination value = 48.75%, after 63 days). The interaction of the NH bonds in the PPy chain with the oxide layer, and the formation of molybdate-containing compounds resulted in a considerable enhancement of the epoxy coating adhesion to the metal surface in the presence of GO-PPy + Na2MoO4.
Article
Carbon and carbon-based materials like graphene and graphene oxide exhibit a constantly expanding field of applications in science, medicine, and industry. However, their implementation is still hindered by the absence of a reliable, flexible, and highly productive method of synthesis. Most of the existing methods rely on the use of chemical reagents potentially dangerous for the environment. In this paper, a physical method based on the use of a transient glow-to-arc discharge is developed, and the carbon nanostructures are obtained during a single-step production in a plasma reactor. Argon and oxygen are used to grow either carbon or carbon oxide nanostructures on the surfaces of expanded graphite samples. To enhance the growth of the carbon nanostructures, an anode made of copper is employed in the setup, to serve as a source of the copper catalyst. As a result, complex three-dimensional carbon nanostructures with a density of about 0.01 μm-2 were detected using scanning electron microscopy (SEM) on the entire surface of the sample after the oxygen plasma treatment. An enlarged view of nanostructures shows that they are a composition of 2D and 1D nanostructures connected by jumpers, as well as the presence of tree-like and petal nanostructures with dimensions of approximately 3 μm in length and 30 nm in diameter. The replacement of oxygen with argon led to a significant change in the appearance of nanostructures. Layered 2D graphene-like and tree-like carbon nanostructures capped with copper particles of diameters up to 10 μm were found. The obtained nanostructures suggest that expanded graphite is an excellent source for the production of two-dimensional nanostructures, like graphene and graphene oxide, which can be used as components for field-effect transistors, nanofluidic applications, supercapacitors, and electromagnetic absorbers.
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Lack of uniformity and generation of defects including grain boundaries and wrinkles in graphene coatings synthesized using chemical vapour deposition (CVD) adversely affect the durability of these coatings. In order to control the defect density and to improve the durability of corrosion resistance of the resultant graphene coating, a fundamental understanding of the influence of the CVD parameters on the defect density is of utmost importance. In this study, the influences of hydrogen flow during graphene growth and the cooling rate on the defect density and barrier properties of a graphene coating have been investigated. A thorough microscopic and spectroscopic investigation revealed that (i) slow cooling hindered the formation of graphene coating irrespective of the presence or absence of hydrogen flow, and (ii) under rapid cooling condition, absence of hydrogen flow restricted wrinkle formation on the resultant coating. Diminished wrinkle formation in absence of hydrogen flow significantly improved the durability of the resultant coating. Based on an in-depth electrochemical impedance spectroscopic investigation, a mechanism has been proposed, which was further corroborated with the post-corrosion analyses using X-ray photoelectron spectroscopy and scanning electron microscopy. This study provides a new direction to achieve graphene coatings with minimal defect density and excellent barrier properties.
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In this research, the effect of silane functionalized graphene quantum dots (f-GQDs) on the corrosion resistance of solvent-based epoxy coatings was investigated. The GQDs were prepared under hydrothermal method by using citric acid as precursor at 160 °C for 4 h. In order to increase the structural compatibility between GQDs and polymer matrix, the synthesized GQDs were chemically modified by (3-aminopropyl) triethoxysilane. The GQDs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, fluorescence emission, and transmission electron microscopy. Then, epoxy nanocomposite coatings containing f-GQDs were spray coated on mild steel substrate and the corrosion protection properties of epoxy/f-GQDs were studied via potentiodynamic polarization test and electrochemical impedance spectroscopy. The results showed that the corrosion protection performance of epoxy coatings had improved effectively with addition of low-cost and highly tunable f-GQDs due to their barrier performance in polymer coatings.
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The impact mechanism of graphene nanosheets on the corrosion resistance and protection performance of zinc rich epoxy coatings was investigated. The potential-time measurement, electrochemical impedance spectroscopy (EIS), salt spray fog testing and scanning electron microscopy were used to characterize the protection performance of coatings. A relatively simple EIS model was used to characterize the effect of graphene nanosheets in terms of percolating structure of the zinc rich epoxy coating. The results of corrosion studies revealed that while addition of 0.4 wt% of graphene nanosheets resulted in potent protection performance of zinc rich coating, a low amount of graphene content exhibited a reverse effect. It was concluded that the enhancement of the corrosion protection performance of the ZRE coating in presence of a satisfactory loading of graphene particles could be attributed to the more uniform activation of zinc particles and also the superior percolation action of graphene nanosheets. Moreover, the addition of a proper amount of graphene nanosheets in ZRE coating can provide an enhanced barrier effect against aggressive species and thereby provides a less aggressive environment for corrosion of zinc particles.
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The adsorptive behavior of Urtica Dioica (U.D) leaf extract on the graphene oxide nanosheets (GONs) was examined by experimental and density functional theory (DFT) approaches. Experimental results demonstrated the strengthened adsorption of the Urtica Dioica leaf extract on the GO sheets at acidic pH of 2, leading to the corrosion inhibition of mild steel in chloride solution. It was observed that the inhibition effects of GO-U.D sheets enhanced in the presence of Zn²⁺ cations in solution and coating phases. The DFT results revealed the physisorption and chemisorption of inhibitors onto GO surfaces.
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Three-dimensional (3D) graphene oxide (GO) nanosheets were utilized as a unique versatile platform for fabrication of an effective anti-corrosion system through a Layer-by-Layer (L-b-L) assembly technique. In this way, the highly ordered crystalline polyaniline (Pani) nanofibers and green corrosion inhibitors (GI) were synthesized. Sustainable corrosion inhibitors were obtained from the extract of Urtica Dioica leaves. The GO-Pani-GI nanosheets were characterized by Fourier transform infrared spectroscopy (FT-IR), high resolution-transmission electron microscopy (HR-TEM), field-emission scanning electron microscopy (FE-SEM), UV-visible spectroscopy and thermal gravimetric analysis (TGA). In addition, the adsorption features of Pani onto GO sheets and its binding propensity against GIs were assessed by applying first-principles quantum mechanics (QM) modeling approaches. The anti-corrosion properties of the GO-Pani-GI were then examined using electrochemical impedance spectroscopy (EIS) and polarization test. The results achieved from QM modeling studies demonstrated that the Pani strongly anchored to GO surfaces via physisorption mechanism. Computations further declared that all GIs interacted with Pani through intermolecular H-bonds. Moreover, the experimental investigations revealed the superior anti-corrosion performance of multilayered graphene nanocomposites.
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In this paper, corrosion potential and impedance response of the graphene-modified low-zinc waterborne epoxy anticorrosion coating with different compositions were measured experimentally. Microstructure impedance analysis approach was proposed, which was applied to analyze in detail the system impedance and to clarify the variation of coating state as well as the role of graphene in the coating. Results showed that the variation course of coating state was divided into four stages: activation stage; cathodic protection stage; shielding protection stage; and failure stage. Graphene formed numerous isolation layers in the coating to hinder the diffusion of aggressive particles like water and oxygen as well as corrosion products, which played a certain shielding protective role. Moreover, graphene was a good electron conductor, which enabled the outer layer zinc to continue to constitute a galvanic couple with the iron substrate after cathodic protection stage, thereby prolonging the protective effect of the coating to some extent.
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In the present work aminoazobenzene (AAB) and diaminobenzene (DAB) functionalized graphene oxide composites have been synthesized and characterized by their FT-IR, XRD, TEM, Raman and XPS spectra. The inhibition effect of these two functionalized graphene oxides was evaluated on mild steel corrosion in 1 M hydrochloric acid solution using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods. Electrochemical results showed that both the composites act as efficient corrosion inhibitors and their inhibition efficiencies increase with concentration. Aminoazobenzene functionalized graphene oxide (AAB-GO) and diaminobenzene functionalized graphene oxide (DAB-GO) exhibited maximum inhibition efficiencies of 94.65% and 92.04%, respectively at concentration as low as 25 mgL⁻¹. Electrochemical impedance spectroscopy (EIS) study suggests that both investigated inhibitors inhibit mild steel corrosion by adsorbing on the metallic surface. Potentiodynamic polarization study suggests that studied composites act as mixed type inhibitors and predominantly behave as cathodic inhibitors. Scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray spectroscopy (EDX) techniques were used for surface characterization. EDX analysis further confirmed the adsorption of inhibitors onto the metallic surface. The several DFT based indices such as EHOMO, ELUMO, energy band gap (ΔE; ELUMO–EHOMO), global hardness (η), softness (σ) and fraction of the electron transfer (ΔN) show that AAB-GO is a better inhibitor than DAB-GO.
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This study introduces a novel surface treatment approach of steel substrate by covalent modification of graphene oxide (fGO) nanosheets with 3-aminopropyltriethoxysilane to improve the adhesion and corrosion protection properties of an epoxy coating. The effect of fGO film on the epoxy coating performance was studied by field-emission scanning electron microscopy (FE-SEM), X-Ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), Pull-off adhesion, salt spray and cathodic delamination tests. Results revealed that deposition of fGO film on steel surface can effectively improve the adhesion strength and corrosion protection properties and reduce the cathodic delamination rate of the epoxy coating.
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This study reports a new strategy for providing ZRC with enhanced cathodic and barrier protection mechanisms simultaneously. For this purpose, the graphene oxide (GO) nanosheets were modified by highly crystalline and conductive polyaniline (PANI) nanofibers in the form of Emeraldine salt (ES) through an in situ polymerization of aniline in the presence of GO as an oxidant. The aniline polymerization in the presence of GO and the PANI nanofibers deposition on the GO surface were exhibited by Fourier transform infrared (FT-IR) spectroscopy and high resolution-transmittance electron microscopy (HR-TEM). In addition to these the X-ray diffraction (XRD) patterns confirmed the deposition of highly crystalline PANI nanofibers on the GO and between the GO layers. Inclusion of 0.1 wt.% GO and GO-PANI nanosheets into the ZRC sample remarkably enhanced its corrosion protection performance. Salt spray, open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements revealed that both the cathodic protection properties and barrier performance of the ZRC were improved after addition of 0.1 wt.% GO and GO-PANI nanossheets to the ZRC sample. The most pronounced improvement in the ZRC properties was obtained using GO-PANI. The results obtained from field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy and XRD analysis confirmed lower degree of zinc particles oxidation and steel substrate corrosion in the case of ZRC including GO-PANI nanosheets compared to other samples.
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Based on the situ preparation of silica nanoparticles (SiO2) on the surface of Graphene nanoplatelets (GNPs) in the previous work, these unique three dimensional (3D) materials were introduced into epoxy resin to study the reinforcing and toughening synergy effect on the composites. Firstly, the tensile tests showed that Graphene/SiO2 hybrid materials attached with different size of SiO2 particles exhibited different reinforcing and toughening effect on the composites. With the increasing of the diameter of SiO2 particles, the toughness and strength properties of the composites firstly improved and then decreased, and when the average diameter was 0.14 μm, the elongation reached the max.. Meanwhile, the fractured surfaces presented on SEM images were consistent with the results of the tensile tests, which further explained the hybrid materials increased the interfacial adhesion between the fillers and matrix, leading to significant improvement in mechanical properties. Moreover, the DSC curves demonstrated that Graphene/SiO2 hybrid materials accelerated the curing process of epoxy resin due to the cross-link structure between fillers and matrix. Lastly, the crack propagation modes were built to clarify the synergy effect mechanism of reinforcing and toughening on nanoparticles/epoxy resin composites.
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In the present work, the electrochemical corrosion behavior of magnesium (Mg) and thin layer graphene coated Mg (Mg/graphene) are studied in different salt electrolyte such as NaCl, KCl and Na2SO4. The phase structure, crystallinity, and surface morphology of the samples are investigated using X-ray diffraction (XRD) analysis, scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDAX), and Raman spectroscopy techniques. The electrochemical corrosion behavior of the Mg and graphene coated Mg are also investigated using Electrochemical Impedance Spectroscopy (EIS) analysis. The tafel plot reveals that the corrosion of Mg drastically drops when coated with thin layer graphene (Mg/graphene) compared to Mg in KCl electrolyte. Moreover, the EIS confirms that Mg/graphene sample shows improve corrosion resistance and lower corrosion rate in KCl solution compare to all other electrolytes studied in the present system.
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Graphene can be used as an excellent protection material because of its barrier properties. This work reports a promising application of metronidazole (MET) modified graphene oxide (GO) composites (GME) for the corrosion protection of steel. The composites were synthesized by using the carboxyl of GO and hydroxyl of MET with the help of Maleic anhydride (MA), and dispersing the sheets into epoxy resin at a low weight fraction of 0.2.wt %. The UV-absorption spectrum reveal that MET can be detected in the NaCl (3.5 wt. %) solution. The electrochemical impedance spectroscopy (EIS) test show that the corrosion resistant performance is significantly enhanced by the addition of GME hybrids to epoxy than GO. The scratched test illustrate that less of corrosion products formed in the scratch of steel coated by GME. The strategy of corrosion inhibitor modified graphene oxide can be extended to develop new graphene-based materials with other excellent materials for the protection of metal components.