- Email: [email protected]
A facile method for the modification of graphene nanosheets as promising anticorrosion pigments
Accepted Manuscript A Facile Method for the Modification of Graphene Nanosheets as Promising Anticorrosion Pigments Wen Sun, Lida Wang, Zhengqing Yang, Tianzhen Zhu, Tingting Wu, Chuang Dong, Guichang Liu PII: DOI: Reference:
S0167-577X(18)30858-9 https://doi.org/10.1016/j.matlet.2018.05.105 MLBLUE 24405
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
21 March 2018 8 May 2018 23 May 2018
Please cite this article as: W. Sun, L. Wang, Z. Yang, T. Zhu, T. Wu, C. Dong, G. Liu, A Facile Method for the Modification of Graphene Nanosheets as Promising Anticorrosion Pigments, Materials Letters (2018), doi: https:// doi.org/10.1016/j.matlet.2018.05.105
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
A Facile Method for the Modification of Graphene Nanosheets as Promising Anticorrosion Pigments Wen Sun,†,‡,// Lida Wang,† Zhengqing Yang,† Tianzhen Zhu,† Tingting Wu,†,§ Chuang Dong,‡ and Guichang Liu*,† †
School of Chemical Engineering, ‡Key Lab for Materials Modification by Laser, Ion and Electron Beams of Education Ministry, and
§
State Key Lab of Fine Chemicals,
Carbon Research Laboratory, Centre for Nano Materials and Science, Dalian University of Technology, 2 Linggong Road, Dalian 116024, P. R. China //
Material Corrosion and Protection Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Zigong, 643099, China
*Corresponding Author. E-mail: [email protected]; Tel./Fax: +86-411-84986047 Abstract: A facile chemical vapor deposition (CVD) method was developed to modify
graphene
nanosheets
with
molecular-sized
polydimethylsiloxane
(PDMS-GNSs) in this work. Influences of the surface modification on microstructure and dispersibility of GNSs, as well as their performance as anticorrosion pigments, have been investigated. The experimental results showed that the morphology of PDMS-GNSs is similar to that of GNSs, the thickness of PDMS-GNSs increases 0.23 nm as compared to GNSs, and PDMS-GNSs exhibit a significantly enhanced dispersibility in common paint solvents and ability to reinforce the anticorrosion performance of epoxy coating. This method has wide application prospects in anticorrosion field. Keywords:
Graphene;
Polydimethylsiloxane;
Nanocomposites;
Modification;
Corrosion 1. Introduction Graphene, a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice, has been reported to be a promising material for anticorrosion due to its impermeability to any molecule and almost all the ions.[1-3] However, defect-free graphene has very inert surface properties due to the non-polar covalent double bonds, which weakens the interactions between graphene and polymer molecules.[4] Additionally, graphene is particularly prone to aggregate due to strong π–π interactions, hydrophobic interactions, and van der Waals forces.[5] Therefore, surface modification of graphene plays an important role in preparing graphene-based 1
polymer nanocomposites with high performance.[6,7] To our best knowledge, all the existing modification methods of graphene for anticorrosion applications are wet-chemical method.[8-10] However, disadvantages including tedious procedures, high production costs and environmental pollution would hinder their practical application. In this paper, in order to overcome the disadvantage of wet-chemical method, we demonstrate a facile CVD-based dry-chemical method for the modification of graphene. 2. Experimental 2.1 Preparation of PDMS-GNSs Expandable graphite was heated at 1000 °C for 10 s in a muffle furnace. Then, the expanded graphite was exfoliated into graphene nanosheets (GNSs) with ultrasonic assistance in 5 mg/mL dishwashing liquid for 4 hours. After washing with deionized water and freeze drying, the as-prepared GNSs (1.0 g) and PDMS (10 g) were sealed into a steel vessel and maintained at 300 °C for 5 h. 2.2 Preparation of PDMS-GNSs/epoxy nanocomposite coating Firstly, a certain amount of PDMS-GNSs was ultrasonically dispersed in 10 mL isopropanol. Then, 4 g epoxy resin was mixed into the dispersion. Subsequently, the mixture was maintained at 80 °C for 6 h to completely evaporate the isopropanol solvent. After cooling to room temperature, 1.0 g T31, 0.1 g defoaming agent and 0.1 g leveling agent was successively dissolved in 1.5 mL acetone and added to the mixture of PDMS-GNSs and epoxy resin. The well-mixed paint was allowed to stand for 30 minutes, and then coating onto the surface of a brass specimen. The coating was placed horizontally for 24 h and subsequently maintained at 80 °C for 2 h. The final coating thickness is measured to be ~50±3 μm. 3. Results and Discussion Scanning electron microscope (SEM) images reveal that the expanded graphite has a worm-like porous structure, which is composed of both cross-linked and layer-by-layer stacked large-sized GNSs (Figure 1a). Such a structure greatly increases the surface area of expanded graphite, making ethanol molecules be easily adsorbed onto the GNSs surface via Van der Waals force. Under strongly ultrasonic concussion, growth and collapse of micrometer-sized bubbles and voids in water/ethanol occur, resulting in the formation of cavitation. The collapse of cavitation at the liquid/GNSs interface would further converse to micro-jet towards 2
GNSs surface, which gives rise to a tearing effect. Consequently, the combination of exfoliation effect and tearing effect results in the exfoliation of expanded graphite into small-sized GNSs (Figure 1b). Nevertheless, the SEM image further confirms that the obtained GNSs possess an ultra-thin structure. After modification, PDMS-GNSs exhibit a similar morphology to that of GNSs, which indicates that the CVD-grown PDMS on GNSs has a very small size (Figure 1c). Raman spectra show that the as-prepared GNSs and PDMS-GNSs have few defects and are composed of multi-layer graphene with an inter-planar stacking structure (Figure 1d).[11,12]
Figure 1. SEM images of (a) low-magnified expanded graphite (50 ×), inset: high-magnified expanded graphite (500 ×), (b) GNSs and (c) PDMS-GNSs. (d) Raman spectra of GNSs and PDMS-GNSs. Transmission electron microscope (TEM) images shown in Figure 2a and c reveal that the GNSs have a smooth surface, whereas the PDMS-GNSs have a rough surface, on which there are numerous nano-sized particles. Additionally, Atomic force microscopy (AFM, Digital Instruments NanoscopeV, USA) reveals that the individual GNSs and PDMS-GNSs are composed of multi-layer graphene with an average thickness of 1.33 and 1.56 nm, respectively (Figure 2b and d). Therefore, it can be inferred that the CVD-grown PDMS particles on the GNSs surface is molecular-sized. The dispersibility of the as-prepared PDMS-GNSs in several common paint solvents are also studied in this work. Apparently, most of the PDMS-GNSs dispersions remain unchanged after being kept for 12 h at room temperature, whereas most of the GNSs 3
dispersions exhibit noticeable precipitation (Figure 2e and f). This finding indicates that the dispersibility of PDMS-GNSs in most paint solvents is better than that of GNSs.
Figure 2. (a) TEM and (b) AFM image of GNSs; (c) TEM and (d) AFM image of PDMS-GNSs; Photographs of (f) GNSs and (e) PDMS-GNSs dispersed in different paint solvents (from left to right: H2O, H2O/surfactant, acetone, 1-methyl-2-pyrrolidinone, dimethyl sulfoxide, methanol, ethanol, isopropanol, toluene, o-xylene, acetic ether, glycidyl phenyl ether and o-dichlorobenzene). Figure 3 presents the analytic results of X-ray photoelectron spectroscopy (XPS). Compared with GNSs, two new characteristic peaks (Si2p, Si2s) originating from PDMS appear in the XPS spectrum of PDMS-GNSs, providing additional evidence of successful modification of PDMS on the GNSs surface (Figure 3a). As shown in 4
Figure 3b, four peaks can be observed the C1s XPS spectrum of GNSs, including graphene skeleton (C-C/C=C, 284.8 eV), hydroxyl (C-O, 285.3 eV), epoxyl (C-O-C, 286.4 eV) and carboxyl (O=C-O, 288.7 eV). After modification, the C1s XPS spectrum of PDMS-GNSs reveals that the peak of carboxyl disappears due to heating and a new peak of C-Si appears at 283.8 eV (Figure 3c); the Si2p XPS spectra of PDMS-GNSs shows that Si-C (102.1 eV) and Si-O-Si (103.2 eV) (Figure 3d), which further confirms the presence of PDMS on GNSs surface.
Figure 3. (a) XPS spectra of GNSs and PDMS-GNSs; (b) C1s spectrum of GNSs; (c) C1s spectrum of PDMS-GNSs and (d). Si2p spectrum of PDMS-GNSs. After being immersed in 3.5 wt.% NaCl aqueous solution for 7 days, the anticorrosion performances of epoxy coatings loading with 0~5 wt.% PDMS-GNSs and 5 wt.% GNSs are shown in Figure 4. The Bode-modulus plots show that, with the increase of PDMS-GNSs loading, the coating modulus at 0.01 Hz tends to increase over a loading range of 0.01~3 wt.%, and then decrease (Figure 4a). The Bode-phase plot of neat epoxy coating shows a peak appears at frequencies ranging from 100 to 10-1 Hz, which is ascribed to the corrosion of brass substrate, and a peak appears at frequencies ranging from 105 to 101 Hz, which is attributed to the capacitive response of coating, demonstrating it has a poor anticorrosion performance (Figure 4b). When being reinforced with PDMS-GNSs, only one peak due to coating responses in the 5
frequencies range of 105-10-1 Hz is observed in the Bode-phase plots of epoxy coatings, which reveals their high anticorrosive performance. However, as revealed by Bode-phase plots, 5 wt.% GNSs so excessive that it degrades the anticorrosion performance of epoxy coating. The data are further analyzed by the Zsimpwin software using the equivalent circuits shown in Figure 4c. The fitted results of coating resistance (Rc), which is an important parameter for evaluating the anticorrosion performance of coatings, are shown in Figure 4d. It is clear that the Rc of neat epoxy coating is ~4.1×107 Ω·cm2. When incorporating only 0.01 wt.% PDMS-GNSs into the matrix of epoxy coating, the Rc increases sharply to ~3.2×108 Ω·cm2. Furthermore, the Rc gradually increase to ~2.8 × 108 Ω·cm2 with further increasing the PDMS-GNSs loading (0.01~1 wt.%) and then keeps almost unchanged over a loading range of 1~3 wt.%. The Rc tends to decrease when embedding excessive PDMS-GNSs (5 wt.%). However, PDMS-GNSs still possess a much stronger ability to enhance the anticorrosion performance of coatings at 5 w.% loading than GNSs because the Rc of PDMS-GNSs/epoxy is three orders of magnitude higher than that of GNSs/epoxy.
Figure 4. (a) Bode-modulus and (b) Bode-phase plots of coatings; (c) Equivalent circuits; (d) Fitted coating resistance. 4. Conclusions Molecular-sized PDMS particles were deposited successfully on the surface of GNSs through a facile CVD method. The dispersibility of PDMS-GNSs in most paint 6
solvents are greatly improved due to the surface modification. Compared to GNSs, PDMS-GNSs are more excellent anticorrosion pigments. Epoxy coating reinforced by only 0.01 wt.% PDMS-GNSs exhibits a coating resistance which is one order of magnitude higher than that of neat epoxy coating. In addition, PDMS-GNSs is able to enhance the anticorrosion performance of coatings at a loading as high as 5 wt.%. Acknowledgements This work was supported by the General Financial Grant from the China Postdoctoral Science Foundation (No. 2017M610177); the National Natural Science Foundation of China (No. 21703026, 51671047); the Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan Province (No. 2017CL16) and Fundamental Research Funds for the Central Universities (No. DUT16RC(3)106). References [1] X. Xu, D. Yi, Z. Wang, et al. Adv. Mater. 30(6) (2018) 1702944. [2] V. Berry. Carbon 62 (2013) 1. [3] Y. Su, V. G. Kravets, S.L. Wong, et al. Nair. Nat. Commun. 5 (2014) 4843. [4] M. Terrones, O. Martín, M. González, et al. Adv. Mater. 23(44) (2011) 5302. [5] M. Tang, T. Wu, H. Na, et al. Mater. Res. Bull. 63 (2015) 248. [6] J.R. Potts, D.R. Dreyer, C.W. Bielawski, et al. Polymer 52(1) (2011) 5. [7] T. Kuilla, S. Bhadra, D.Yao, et al. Prog. Polym. Sci. 35(11) (2010) 1350. [8] W. Sun, L. Wang, T. Wu, et al. Chem. Mater. 27(7) (2015) 2367. [9] B. Ramezanzadeh, S. Niroumandrad, A. Ahmadi, et al. Corros. Sci. 103 (2016) 283-304. [10] C.-H. Chang, T.-C Huang, C.-W. Peng, et al. Carbon 50(14) (2012) 5044. [11] J. Lin, H. Jia, H. Liang, et al. Adv. Sci. 5(3) (2018) 1700687. [12] J. Lin, H. Jia, Y. Cai, et al. J. Mater. Chem. A 6(3) (2018) 908-917.
7
Highlights
A facile CVD-based dry-chemical method was developed to modify graphene.
Modified graphene exhibits an improved dispersibility in organic solvents.
Modified graphene greatly increases coating resistance at 0.01~5 wt.% loading.
8
S0167-577X(18)30858-9 https://doi.org/10.1016/j.matlet.2018.05.105 MLBLUE 24405
To appear in:
Materials Letters
Received Date: Revised Date: Accepted Date:
21 March 2018 8 May 2018 23 May 2018
Please cite this article as: W. Sun, L. Wang, Z. Yang, T. Zhu, T. Wu, C. Dong, G. Liu, A Facile Method for the Modification of Graphene Nanosheets as Promising Anticorrosion Pigments, Materials Letters (2018), doi: https:// doi.org/10.1016/j.matlet.2018.05.105
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
A Facile Method for the Modification of Graphene Nanosheets as Promising Anticorrosion Pigments Wen Sun,†,‡,// Lida Wang,† Zhengqing Yang,† Tianzhen Zhu,† Tingting Wu,†,§ Chuang Dong,‡ and Guichang Liu*,† †
School of Chemical Engineering, ‡Key Lab for Materials Modification by Laser, Ion and Electron Beams of Education Ministry, and
§
State Key Lab of Fine Chemicals,
Carbon Research Laboratory, Centre for Nano Materials and Science, Dalian University of Technology, 2 Linggong Road, Dalian 116024, P. R. China //
Material Corrosion and Protection Key Laboratory of Sichuan Province, Sichuan University of Science & Engineering, Zigong, 643099, China
*Corresponding Author. E-mail: [email protected]; Tel./Fax: +86-411-84986047 Abstract: A facile chemical vapor deposition (CVD) method was developed to modify
graphene
nanosheets
with
molecular-sized
polydimethylsiloxane
(PDMS-GNSs) in this work. Influences of the surface modification on microstructure and dispersibility of GNSs, as well as their performance as anticorrosion pigments, have been investigated. The experimental results showed that the morphology of PDMS-GNSs is similar to that of GNSs, the thickness of PDMS-GNSs increases 0.23 nm as compared to GNSs, and PDMS-GNSs exhibit a significantly enhanced dispersibility in common paint solvents and ability to reinforce the anticorrosion performance of epoxy coating. This method has wide application prospects in anticorrosion field. Keywords:
Graphene;
Polydimethylsiloxane;
Nanocomposites;
Modification;
Corrosion 1. Introduction Graphene, a single layer of carbon atoms arranged in a two-dimensional honeycomb lattice, has been reported to be a promising material for anticorrosion due to its impermeability to any molecule and almost all the ions.[1-3] However, defect-free graphene has very inert surface properties due to the non-polar covalent double bonds, which weakens the interactions between graphene and polymer molecules.[4] Additionally, graphene is particularly prone to aggregate due to strong π–π interactions, hydrophobic interactions, and van der Waals forces.[5] Therefore, surface modification of graphene plays an important role in preparing graphene-based 1
polymer nanocomposites with high performance.[6,7] To our best knowledge, all the existing modification methods of graphene for anticorrosion applications are wet-chemical method.[8-10] However, disadvantages including tedious procedures, high production costs and environmental pollution would hinder their practical application. In this paper, in order to overcome the disadvantage of wet-chemical method, we demonstrate a facile CVD-based dry-chemical method for the modification of graphene. 2. Experimental 2.1 Preparation of PDMS-GNSs Expandable graphite was heated at 1000 °C for 10 s in a muffle furnace. Then, the expanded graphite was exfoliated into graphene nanosheets (GNSs) with ultrasonic assistance in 5 mg/mL dishwashing liquid for 4 hours. After washing with deionized water and freeze drying, the as-prepared GNSs (1.0 g) and PDMS (10 g) were sealed into a steel vessel and maintained at 300 °C for 5 h. 2.2 Preparation of PDMS-GNSs/epoxy nanocomposite coating Firstly, a certain amount of PDMS-GNSs was ultrasonically dispersed in 10 mL isopropanol. Then, 4 g epoxy resin was mixed into the dispersion. Subsequently, the mixture was maintained at 80 °C for 6 h to completely evaporate the isopropanol solvent. After cooling to room temperature, 1.0 g T31, 0.1 g defoaming agent and 0.1 g leveling agent was successively dissolved in 1.5 mL acetone and added to the mixture of PDMS-GNSs and epoxy resin. The well-mixed paint was allowed to stand for 30 minutes, and then coating onto the surface of a brass specimen. The coating was placed horizontally for 24 h and subsequently maintained at 80 °C for 2 h. The final coating thickness is measured to be ~50±3 μm. 3. Results and Discussion Scanning electron microscope (SEM) images reveal that the expanded graphite has a worm-like porous structure, which is composed of both cross-linked and layer-by-layer stacked large-sized GNSs (Figure 1a). Such a structure greatly increases the surface area of expanded graphite, making ethanol molecules be easily adsorbed onto the GNSs surface via Van der Waals force. Under strongly ultrasonic concussion, growth and collapse of micrometer-sized bubbles and voids in water/ethanol occur, resulting in the formation of cavitation. The collapse of cavitation at the liquid/GNSs interface would further converse to micro-jet towards 2
GNSs surface, which gives rise to a tearing effect. Consequently, the combination of exfoliation effect and tearing effect results in the exfoliation of expanded graphite into small-sized GNSs (Figure 1b). Nevertheless, the SEM image further confirms that the obtained GNSs possess an ultra-thin structure. After modification, PDMS-GNSs exhibit a similar morphology to that of GNSs, which indicates that the CVD-grown PDMS on GNSs has a very small size (Figure 1c). Raman spectra show that the as-prepared GNSs and PDMS-GNSs have few defects and are composed of multi-layer graphene with an inter-planar stacking structure (Figure 1d).[11,12]
Figure 1. SEM images of (a) low-magnified expanded graphite (50 ×), inset: high-magnified expanded graphite (500 ×), (b) GNSs and (c) PDMS-GNSs. (d) Raman spectra of GNSs and PDMS-GNSs. Transmission electron microscope (TEM) images shown in Figure 2a and c reveal that the GNSs have a smooth surface, whereas the PDMS-GNSs have a rough surface, on which there are numerous nano-sized particles. Additionally, Atomic force microscopy (AFM, Digital Instruments NanoscopeV, USA) reveals that the individual GNSs and PDMS-GNSs are composed of multi-layer graphene with an average thickness of 1.33 and 1.56 nm, respectively (Figure 2b and d). Therefore, it can be inferred that the CVD-grown PDMS particles on the GNSs surface is molecular-sized. The dispersibility of the as-prepared PDMS-GNSs in several common paint solvents are also studied in this work. Apparently, most of the PDMS-GNSs dispersions remain unchanged after being kept for 12 h at room temperature, whereas most of the GNSs 3
dispersions exhibit noticeable precipitation (Figure 2e and f). This finding indicates that the dispersibility of PDMS-GNSs in most paint solvents is better than that of GNSs.
Figure 2. (a) TEM and (b) AFM image of GNSs; (c) TEM and (d) AFM image of PDMS-GNSs; Photographs of (f) GNSs and (e) PDMS-GNSs dispersed in different paint solvents (from left to right: H2O, H2O/surfactant, acetone, 1-methyl-2-pyrrolidinone, dimethyl sulfoxide, methanol, ethanol, isopropanol, toluene, o-xylene, acetic ether, glycidyl phenyl ether and o-dichlorobenzene). Figure 3 presents the analytic results of X-ray photoelectron spectroscopy (XPS). Compared with GNSs, two new characteristic peaks (Si2p, Si2s) originating from PDMS appear in the XPS spectrum of PDMS-GNSs, providing additional evidence of successful modification of PDMS on the GNSs surface (Figure 3a). As shown in 4
Figure 3b, four peaks can be observed the C1s XPS spectrum of GNSs, including graphene skeleton (C-C/C=C, 284.8 eV), hydroxyl (C-O, 285.3 eV), epoxyl (C-O-C, 286.4 eV) and carboxyl (O=C-O, 288.7 eV). After modification, the C1s XPS spectrum of PDMS-GNSs reveals that the peak of carboxyl disappears due to heating and a new peak of C-Si appears at 283.8 eV (Figure 3c); the Si2p XPS spectra of PDMS-GNSs shows that Si-C (102.1 eV) and Si-O-Si (103.2 eV) (Figure 3d), which further confirms the presence of PDMS on GNSs surface.
Figure 3. (a) XPS spectra of GNSs and PDMS-GNSs; (b) C1s spectrum of GNSs; (c) C1s spectrum of PDMS-GNSs and (d). Si2p spectrum of PDMS-GNSs. After being immersed in 3.5 wt.% NaCl aqueous solution for 7 days, the anticorrosion performances of epoxy coatings loading with 0~5 wt.% PDMS-GNSs and 5 wt.% GNSs are shown in Figure 4. The Bode-modulus plots show that, with the increase of PDMS-GNSs loading, the coating modulus at 0.01 Hz tends to increase over a loading range of 0.01~3 wt.%, and then decrease (Figure 4a). The Bode-phase plot of neat epoxy coating shows a peak appears at frequencies ranging from 100 to 10-1 Hz, which is ascribed to the corrosion of brass substrate, and a peak appears at frequencies ranging from 105 to 101 Hz, which is attributed to the capacitive response of coating, demonstrating it has a poor anticorrosion performance (Figure 4b). When being reinforced with PDMS-GNSs, only one peak due to coating responses in the 5
frequencies range of 105-10-1 Hz is observed in the Bode-phase plots of epoxy coatings, which reveals their high anticorrosive performance. However, as revealed by Bode-phase plots, 5 wt.% GNSs so excessive that it degrades the anticorrosion performance of epoxy coating. The data are further analyzed by the Zsimpwin software using the equivalent circuits shown in Figure 4c. The fitted results of coating resistance (Rc), which is an important parameter for evaluating the anticorrosion performance of coatings, are shown in Figure 4d. It is clear that the Rc of neat epoxy coating is ~4.1×107 Ω·cm2. When incorporating only 0.01 wt.% PDMS-GNSs into the matrix of epoxy coating, the Rc increases sharply to ~3.2×108 Ω·cm2. Furthermore, the Rc gradually increase to ~2.8 × 108 Ω·cm2 with further increasing the PDMS-GNSs loading (0.01~1 wt.%) and then keeps almost unchanged over a loading range of 1~3 wt.%. The Rc tends to decrease when embedding excessive PDMS-GNSs (5 wt.%). However, PDMS-GNSs still possess a much stronger ability to enhance the anticorrosion performance of coatings at 5 w.% loading than GNSs because the Rc of PDMS-GNSs/epoxy is three orders of magnitude higher than that of GNSs/epoxy.
Figure 4. (a) Bode-modulus and (b) Bode-phase plots of coatings; (c) Equivalent circuits; (d) Fitted coating resistance. 4. Conclusions Molecular-sized PDMS particles were deposited successfully on the surface of GNSs through a facile CVD method. The dispersibility of PDMS-GNSs in most paint 6
solvents are greatly improved due to the surface modification. Compared to GNSs, PDMS-GNSs are more excellent anticorrosion pigments. Epoxy coating reinforced by only 0.01 wt.% PDMS-GNSs exhibits a coating resistance which is one order of magnitude higher than that of neat epoxy coating. In addition, PDMS-GNSs is able to enhance the anticorrosion performance of coatings at a loading as high as 5 wt.%. Acknowledgements This work was supported by the General Financial Grant from the China Postdoctoral Science Foundation (No. 2017M610177); the National Natural Science Foundation of China (No. 21703026, 51671047); the Opening Project of Material Corrosion and Protection Key Laboratory of Sichuan Province (No. 2017CL16) and Fundamental Research Funds for the Central Universities (No. DUT16RC(3)106). References [1] X. Xu, D. Yi, Z. Wang, et al. Adv. Mater. 30(6) (2018) 1702944. [2] V. Berry. Carbon 62 (2013) 1. [3] Y. Su, V. G. Kravets, S.L. Wong, et al. Nair. Nat. Commun. 5 (2014) 4843. [4] M. Terrones, O. Martín, M. González, et al. Adv. Mater. 23(44) (2011) 5302. [5] M. Tang, T. Wu, H. Na, et al. Mater. Res. Bull. 63 (2015) 248. [6] J.R. Potts, D.R. Dreyer, C.W. Bielawski, et al. Polymer 52(1) (2011) 5. [7] T. Kuilla, S. Bhadra, D.Yao, et al. Prog. Polym. Sci. 35(11) (2010) 1350. [8] W. Sun, L. Wang, T. Wu, et al. Chem. Mater. 27(7) (2015) 2367. [9] B. Ramezanzadeh, S. Niroumandrad, A. Ahmadi, et al. Corros. Sci. 103 (2016) 283-304. [10] C.-H. Chang, T.-C Huang, C.-W. Peng, et al. Carbon 50(14) (2012) 5044. [11] J. Lin, H. Jia, H. Liang, et al. Adv. Sci. 5(3) (2018) 1700687. [12] J. Lin, H. Jia, Y. Cai, et al. J. Mater. Chem. A 6(3) (2018) 908-917.
7
Highlights
A facile CVD-based dry-chemical method was developed to modify graphene.
Modified graphene exhibits an improved dispersibility in organic solvents.
Modified graphene greatly increases coating resistance at 0.01~5 wt.% loading.
8