Robust functional nanohybrid surface enables long-term oily wastewater remediation.

Fabrication of rGO/CoSx-rGO/rGO hybrid film via coassembly and sulfidation of 2D metal organic framework nanoflakes and graphene oxide as free-standing supercapacitor electrode

Nano-Al2O3 particles and graphene oxide (GO) nanosheets were modified by 3-aminopropyltriethoxysilane (KH550), and then dispersed in epoxy resin, and finally modified-Al2O3/epoxy, modified-GO/epoxy and modified-Al2O3@GO/epoxy composite coatings were prepared on steel sheets by the scraping stick method. The microstructure, phase identification, surface bonding and composition of the nanoparticles were characterized by SEM, XRD, FT-IR, and Raman spectroscopy, respectively. The hardness of the coating was assessed by the pencil hardness method. The abrasion resistance of the coating was tested by a sand washing machine. The corrosion resistance of the coating was assessed using salt spray, a long-period immersion test, potentiodynamic polarization curves and electrochemical impedance spectra. With the addition of a small amount of nanoparticles, the dispersion of nanoparticles in the epoxy resin was good. When the content of nano-Al2O3 particles was equal to 1.5 wt%, the particles in the epoxy exhibited the best dispersion and stability. However, the GO and Al2O3@GO nanofillers in the epoxy resin exhibited poor dispersion and stability. The hardness, abrasion and corrosion resistance of the composite coatings were improved with the addition of a small amount of nanoparticles, but the performance began to decline after exceeding a certain content range of the nanoparticles. A relatively good abrasion resistance for the coatings was obtained when the content of Al2O3, GO and Al2O3@GO after modification was 1.5 wt%, 0.2 wt% and 0.4 wt%, respectively. The corrosion resistance of the coatings doped with nano-Al2O3 particles was better than that of the coatings incorporating GO nanosheets and Al2O3@GO hybrids. The corrosion mechanism of the composite coatings in 3.5 wt% NaCl solution was addressed and studied.

The morphology and properties of epoxy powder coating with two additives based on allotropic forms of carbon, diamond, and graphene oxide (GO), were studied. The effect of concentrations and preparation methods on the dispersion of GO within the polymer matrix was investigated. Two methods of introducing coating additives were investigated, to the component blend before extrusion and dry-mixed with the sieved powder. The surface roughness, abrasive wear resistance, thickness, as well as glossing of the coating were analysed depending on the type, concentration, and applied method of preparation. The study showed that the quantity of agglomerates in polymer matrix depends on the applied dispersion method. The lowest number of GO agglomerates was obtained by GO sonication before mixing of raw materials. The relationship between the content of GO in the coating and the abrasion resistance was found. The lowest abrasive wear was found for coating with 0.3% GO introduced by extrusion. Both additives, GO and diamond, in various concentrations have an impact on the coating wear resistance.

Influence of Graphene oxide on abrasion resistance and strength of concrete

Graphene-oxide-doped oriented nickel oxide film achieved through brush coating for liquid crystal system

In this paper, a novel ammonia detection hybrid film is proposed based on a graphene oxide (GO)/graphene stack, which shows excellent sensing characteristics at room temperature. It is attributed to the cooperation of GO layer serving as molecular capture layer while graphene serving as conductive layer. GO layer is obtained on chemical vapor deposited graphene film by a simple drop-casting method. The prepared GO/graphene hybrid film is directly transferred to the target substrate without any additional transfer vehicle to reduce possible contamination. The success of the transfer depends on the mechanical strength of GO layer. The thickness of GO layer can scale down to 55 nm while sustaining the transfer process. The best ammonia gas sensing performance is obtained at about 275 nm GO layer thickness and the ammonia detection limit is calculated to be 1.5 ppb. In conclusion, the ammonia gas sensing performance of GO/graphene hybrid film can be significantly improved through GO layer thickness optimization.

Bismuth-magnesium-oxide-based graphene oxide hybrid film for liquid crystal device application

Strong yet tough graphene/graphene oxide hybrid films

Hybrid films of reduced graphene oxide (RGO) and nitrogen-doped graphene quantum dots (N-GQDs) were obtained by processing colloidal dispersions of graphene oxide (GO) and N-GQDs. N-GQDs/RGO films with well-dispersed nanophases were prepared by mechanical spraying of an 80:20 v/v ratio of N-GQDs:GO dispersion on glass substrates at 315 °C. In contrast, multilayer assemblies of N-GQDs/RGO films resulted from the two-step process consisting of a GO film prepared by spin coating on a glass substrate and the subsequent mechanical spraying of the N-GQD dispersion at 300 °C. The nanostructured array was studied using scanning electron microscopy and transmission electron microscopy, showing that the preparation method impacts film morphology and the crystalline structure. The structure and chemical composition of the N-GQDs/RGO hybrid films studied by spectroscopy techniques, such as Raman microscopy and X-ray photoelectron spectroscopy, showed the distribution of N-GQDs in the hybrid film. The assembly of nanocarbons in the resulting hybrid films impacts their optoelectronic and electrochemical properties. Recently, it was observed that graphene itself provides significant enhancement of the Raman signal and the so-called graphene-enhanced Raman scattering (GERS). We tested the N-GQDs/RGO hybrid films as substrates for GERS using crystal violet and methyl blue showing an enhancement factor (EF) of 103 and 102, respectively. In the future, the GERS effect will be a new technology to develop better-performing Raman-based analytical devices that avoid using expensive noble metals.

Detoxification of zearalenone from corn oil by adsorption of functionalized GO systems

To further enhance the abrasion resistance of UHPC in demanding abrasion environments, this study investigated the effects of graphene oxide (GO) on the workability, mechanical properties, and abrasion resistance of UHPC. Utilizing 27Al Nuclear Magnetic Resonance (NMR), 29Si NMR, microhardness, and BET analysis, the study analyzed the mechanisms through which GO influences UHPC’s microstructure in terms of abrasion resistance. Additionally, molecular dynamics simulations were employed to examine the mechanisms by which GO enhances UHPC’s abrasion resistance at the nano and micron scale. The findings show that an optimal amount of GO can improve the mechanical properties and abrasion resistance of UHPC. When 0.03% of GO (by cementitious material mass) was incorporated, the impact on workability was minimal, yet compressive strength increased by approximately 1.80%, flexural strength by 3.02%, impact wear resistance by 1.78%, the abrasion loss rate decreased by 10.01%, ultimate impact energy increased by 1.76%, and the toughness index improved by 10.10%. GO enhances abrasion-resistant UHPC primarily by increasing hydration, refining pore structure, and improving the microstructure of the interfacial transition zone. While GO increases the hydration degree of the UHPC matrix, it does not alter the silicate chain in C-A-S-H gels within the paste. Additionally, the incorporation of graphene oxide can refine the pore structure of the UHPC cement paste and improve the microstructure of the interfacial transition zone (ITZ) between the aggregate and the cement paste. The molecular dynamics simulation reveals that, under abrasive forces, GO forms strong, stable chemical bonds with the C-A-S-H base atoms, significantly enhancing the abrasion resistance of C-A-S-H.

The tunable electrical conductivity of a MWCNT-reduced graphene oxide hybrid film

Petroleum depletion and climate change have inspired research on bio-based polymers and CO2 capture. Tung-oil-based polyols were applied to partially replace polyether-type polyols from petroleum for sustainable polyurethane. Tung-oil-based polyurethane (TBPU), was prepared via a two-step polycondensation, that is, bulk prepolymerization and chain extension reaction. The graphene oxide (GO) was prepared via Hummer’s method. Then, TBPU was composited with the GO at different ratios to form a TBPU/GO hybrid film. The GO/TBPU films were characterized by fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), thermal gravimetric analysis (TGA) and scanning electron microscope (SEM), followed by the measurement of mechanical properties and gas permeability. The results showed that the addition of tung-oil-based polyols enhanced the glass transition temperature and thermal stability of TBPU. The mechanical properties of the hybrid film were significantly improved, and the tensile strength and elongation at break were twice as high as those of the bulk TBPU film. When the GO content was higher than 2.0%, a brittle fracture appeared in the cross section of hybrid film. The increase of GO content in hybrid films improved the selectivity of CO2/N2 separation. When the GO content was higher than 0.35%, the resulting GO agglomeration constrained the gas separation and permeation properties.

Highly Ordered and Dense Thermally Conductive Graphitic Films from a Graphene Oxide/Reduced Graphene Oxide Mixture

Silver nanocubes/graphene oxide hybrid film on a hydrophobic surface for effective molecule concentration and sensitive SERS detection