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

Abstract

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.

Polypyrrole–Dopamine Nanofiber Light-Trapping Coating for Efficient Solar Vapor Generation

“…The broad peaks for granular and fibrous structures at 3430 and 3433 cm –1 , respectively, are due to N–H and O–H stretching vibrations in catechol groups, indicating the successful copolymerization with DA . The peaks at 1700 and 1735 cm –1 for granular and fibrous PPy–DA, respectively, are due to CO stretching vibration, indicating the carbonyl group . In fibrous and granular structures, the peaks at 2958 and 2924 cm –1 (C–H symmetrical and C–H asymmetrical stretching in the aromatic ring, respectively) also confirm the incorporation of DA into PPy …”

“…47 The peaks at 1700 and 1735 cm −1 for granular and fibrous PPy− DA, respectively, are due to CO stretching vibration, indicating the carbonyl group. 48 In fibrous and granular structures, the peaks at 2958 and 2924 cm −1 (C−H symmetrical and C−H asymmetrical stretching in the aromatic ring, respectively) also confirm the incorporation of DA into PPy. 44 We further verified the polymer structures of plane PPy, granular PPy−DA, and fibrous PPy−DA by X-ray photoelectron spectroscopy (XPS).…”

Rapid and Local Self-Healing Ability of Polyurethane Nanocomposites Using Photothermal Polydopamine-Coated Graphene Oxide Triggered by Near-Infrared Laser

“…In contrast, the PDA–rGO spectrum showed not only a strong, broad band between 3600 and 2800 cm −1 corresponding to –OH but also a characteristic peak at 3230 cm −1 , corresponding to the N–H bond of PDA. In addition, the characteristic peaks of PDA at 1510 and 1120 cm −1 correspond to aromatic N–H and C–N, respectively [ 32 ]. Figure 3 b shows the X-ray diffraction (XRD) patterns of GO and PDA–rGO.…”

“…GO exhibited a strong peak at 2θ = 10.3°, indicating that many oxygen-containing groups were intercalated within the interlayer space. This intense GO peak completely disappeared, and a broad peak appeared in the PDA–rGO diffractogram at 2θ = 24.5°, indicating that GO was successfully reduced by PDA [ 32 ]. Raman spectroscopy is a powerful tool for detecting crystalline disorders and the degree of chemical modification of carbon nanostructures [ 33 ].…”

“…The Raman spectra of GO and PDA–rGO were measured using a 514 nm laser line. Both GO and PDA–rGO showed an obvious G band at 1590 cm −1 (graphite mode) and D band (defect-induced mode) at 1350 cm −1 , as shown in Figure 3 c. The intensity ratio of the D and G bands (I D /I G ), R value (defined as I D /I G , the integrated intensity of the D band divided by the integrated intensity of the G band), is associated with graphene disorder; therefore, it is used to measure the degree of defects [ 32 ]. PDA–rGO showed a slight increase in D band intensity, compared to GO.…”