scholarly journals Polydopamine Modified Graphene Oxide-TiO2 Nanofiller for Reinforcing Physical Properties and Anticorrosion Performance of Waterborne Epoxy Coatings

2019 ◽  
Vol 9 (18) ◽  
pp. 3760 ◽  
Author(s):  
Shuli Wang ◽  
Jiankang Zhu ◽  
Yongchao Rao ◽  
Beibei Li ◽  
Shuhua Zhao ◽  
...  

Nano-polydopamine-graphene oxide-TiO2 (nano-PDA@GO-TiO2) composites were prepared by dopamine modified graphene oxide (GO) and loaded nano-TiO2 on the surface of GO. The structure and morphology of nano-PDA@GO-TiO2 composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman, X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), and Transmission electron microscope (TEM) Results demonstrate that the introduction of dopamine to functionalize the GO could self-polymerize polydopamine (PDA) on the surfaces of the GO and endow abundant chemical groups reduce the GO. The interaction between the GO and nano-TiO2 particles could prevent graphene nanosheets from restacking and nano-TiO2 particles from agglomeration. Nano-PDA@GO-TiO2 composite material was used as the nano-filler, and nano-PDA@GO-TiO2 composites waterborne epoxy resin coatings (PGT/WEP) were prepared by dispersing a different content of nano-PDA@GO-TiO2 composites into waterborne epoxy resin with the help of ultrasonic dispersion and mechanical agitation. The physical properties of PGT/WEP coatings, such as hardness, impact resistance, and adhesion, were tested and the electrochemical performance was evaluated. The results show that dispersing 2% nano-PDA@GO-TiO2 composites in waterborne epoxy resin could significantly improve the physical properties and corrosion resistance of waterborne epoxy resin coating when compared with pure waterborne epoxy coating.

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 89
Author(s):  
Wei Yuan ◽  
Qian Hu ◽  
Jiao Zhang ◽  
Feng Huang ◽  
Jing Liu

This study modified graphene oxide (GO) with hydrophilic octadecylamine (ODA) via covalent bonding to improve its dispersion in silicone-modified epoxy resin (SMER) coatings. The structural and physical properties of ODA-GO were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and contact angle tests. The ODA-GO composite materials were added to SMER coatings by physical mixing. FE-SEM, water absorption, and contact angle tests were used to evaluate the physical properties of the ODA-GO/SMER coatings, while salt spray, electrochemical impedance spectroscopy (EIS), and scanning Kelvin probe (SKP) methods were used to test the anticorrosive performance of ODA-GO/SMER composite coatings on Q235 steel substrates. It was found that ODA was successfully grafted onto the surfaces of GO. The resulting ODA-GO material exhibited good hydrophobicity and dispersion in SMER coatings. The anticorrosive properties of the ODA-GO/SMER coatings were significantly improved due to the increased interfacial adhesion between the nanosheets and SMER, lengthening of the corrosive solution diffusion path, and increased cathodic peeling resistance. The 1 wt.% ODA-GO/SMER coating provided the best corrosion resistance than SMER coatings with other amounts of ODA-GO (including no addition). After immersion in 3.5 wt.% NaCl solution for 28 days, the low-frequency end impedance value of the 1 wt.% ODA-GO/SMER coating remained high, at 6.2 × 108 Ω·cm2.


2019 ◽  
Vol 814 ◽  
pp. 3-11
Author(s):  
Xiang Yu Ren ◽  
Hui Chen ◽  
Jing Wu ◽  
Hong Bo Liu

Microcrystalline graphite (MG) was used as raw material and oxidated by Hummers method. And further the graphene oxide (GO) was obtained by ultrasonic stripping. The TP modified graphene (TPG) was prepared by the surface grafting of pure natural green tea extract tea polyphenols (TP) on the surface of GO. Finally, the TPG/epoxy resin composite was prepared by solution blending and heat-curing moulding method.The characterization of structure and properties of TPG was analyzed by X ray diffraction pattern (XRD), infrared spectroscopy (FT-IR), thermo gravimetric analysis (TGA) and X ray photoelectron spectroscopy (XPS). A universal material testing machine was used to test the mechanical properties of epoxy resin composites with different addition of TPG. Field emission scanning electron microscopy (SEM) was used to observe the tensile-sectional morphology of the composites. The thermal stability of the composites was investigated by thermogravimetry and thermal dilatometer. The experimental results showed that the TP molecule was successfully grafted on the oxygen-containing functional groups of the GO surface through the phenolic hydroxyl group.When the addition of TPG was 1.0 wt%, the decomposition temperature of the epoxy resin was increased by 22.2 °C,and the surface resistivity decreased from 1.35×1014 Ω·m to 1.7×109 Ω·m. When the added amount of TPG was 0.5 wt%, the tensile strength of composites was increased by 13.5% reaching 59.85 MPa.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1950 ◽  
Author(s):  
Na Wang ◽  
Huiying Gao ◽  
Jing Zhang ◽  
Ye Qin ◽  
Deyi Wang

Epoxy resin coatings were prepared with phytic acid-doped graphene oxide (PA-GO) to modify epoxy resins (EP). The aim was to improve the dispersion of GO in waterborne epoxy resin, and thus to improve the corrosion resistance of steel structures. The Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results showed that PA-GO was successfully prepared and has a better dispersion in epoxy resin. This is mainly due to the PA insert, which increased the layer spacing of the GO. The results obtained under the controlled corrosive environment showed that the specimen coated with EP containing 1.0 wt.% PA-GO had better corrosion resistance than other samples. This resistance was also two orders of magnitude higher than pure epoxy coating. The main reason for this is that the dispersion of GO in waterborne epoxy resin had been improved.


2019 ◽  
Vol 137 (1) ◽  
pp. 47710 ◽  
Author(s):  
Wenqian Wu ◽  
Yiting Xu ◽  
Haiyang Wu ◽  
Jinmei Chen ◽  
Min Li ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (49) ◽  
pp. 42836-42844 ◽  
Author(s):  
Katarzyna Pytlakowska ◽  
Violetta Kozik ◽  
Marek Matussek ◽  
Michał Pilch ◽  
Barbara Hachuła ◽  
...  

A novel and selective sorbent for micro-solid phase extraction was synthesized by chemical functionalization of graphene oxide with glycine.


2022 ◽  
Author(s):  
Yong Li ◽  
Zhou Jiang ◽  
Haidong Yu ◽  
Xuebin Zhou ◽  
Peng Yi

Abstract Rare earth-modified graphene oxide (RE-M-GO) materials were successfully prepared by infiltration and heating modifier method. The morphology and phase structure of RE-M-GO were characterized by scanning electron microscopy(SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive spectrometer(EDS). The changes of the chemical structure were indicated by Fourier transform infrared (FTIR). X-ray photoelectron spectroscopy(XPS) was used to study the chemical state of the surface elements of graphene oxide which showed that the rare earth elements were added to the graphene oxide functional groups through the coordination reaction. Additionally, the findings concluded that the effect of modification by Ce is more obvious than La elements and the RE-M-GO materials prepared by the heating modifier method had better dispersibility than infiltration. With activating effect, the rare earth elements grafting to graphene oxide will contribute to its combination with other materials.


2020 ◽  
Vol 137 (45) ◽  
pp. 49405
Author(s):  
Yankun Xie ◽  
Weiqu Liu ◽  
Liyan Liang ◽  
Chunhua Liu ◽  
Maiping Yang ◽  
...  

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nur Laila Hamidah ◽  
Masataka Shintani ◽  
Aynul Sakinah Ahmad Fauzi ◽  
Shota Kitamura ◽  
Elaine G. Mission ◽  
...  

AbstractWater electrolysis is an environment-friendly process of producing hydrogen with zero-carbon emission. Herein, we studied the water vapor electrolysis using a proton-conducting membrane composed of graphene oxide (GO) nanosheets intercalated with cations (Al3+ and Ce3+). We examined the effect of cation introduction on the physical and chemical structures, morphology, thermal and chemical stabilities, and the proton conductivity of stacked GO nanosheet membranes by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoemission spectroscopy (XPS), Raman spectroscopy, atomic force microscopy (AFM), dynamic light scattering (DLS), thermogravimetric-differential thermal analysis (TG-DTA), and electrochemical impedance spectroscopy (EIS). Concentration cell measurements revealed that the cation-modified membranes are pure proton conductors at room temperature. The proton conductivity of a GO membrane was much improved by cation modification. The cation-modified GO membranes, sandwiched with Pt/C electrodes as the cathode and anode, electrolyzed humidified air to produce hydrogen at room temperature, indicating the feasibility of this carbon-based electrochemical device.


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