Graphene oxide (GO) reduced by Stachys lavandulifolia extract (SLE) was produced and characterised. The anti-corrosion behaviour of epoxy coatings containing GO and rGO nanosheets was investigated. FESEM-EDS, FT-IR, a...Graphene oxide (GO) reduced by Stachys lavandulifolia extract (SLE) was produced and characterised. The anti-corrosion behaviour of epoxy coatings containing GO and rGO nanosheets was investigated. FESEM-EDS, FT-IR, and Raman spectroscopy were used to examine the microstructure and chemical composition of the nanosheets and epoxy coatings. EIS experiment was used to explore the corrosion behaviour of the coatings. The O/C ratio for GO and rGO-SLE was found to be 2.5 and 4.5, indicating a decrease in the carbon content after the reduction of GO, confirming the adsorption of SLE onto the GO nanosheets. The successful reduction of GO in the presence of SLE particles was confirmed by disappearing the C=O peak and a significant decrease in the C-O-C bond intensity. The epoxy/rGO- SLE coatings exhibited the highest double-layer thickness and excellent corrosion resistance compared to neat epoxy and epoxy/GO coatings, emphasizing the significant role of rGO in enhancing the protective performance of epoxy coatings. The highest values for total charge transfer and film resistances and the inhibition efficiency were observed to be 6529 Ω·cm^(2) and 90%, respectively, for the epoxy/rGO-SLE coated steel plate. It was also found that the epoxy/0.15 wt.% rGO-SLE coating demonstrates the best corrosion resistance performance.展开更多
Graphene oxide (GO) is a graphene derivatives that has oxygen-containing functional groups on the graphene basal plane, such as hydroxyl, carbonyl, epoxy and carboxyl groups. GO is considered as a promising material f...Graphene oxide (GO) is a graphene derivatives that has oxygen-containing functional groups on the graphene basal plane, such as hydroxyl, carbonyl, epoxy and carboxyl groups. GO is considered as a promising material for biological applications owing to its excellent surface functionalizability, high specific suface area and good biocompatibility. In this study, GO/chitosan hybrid scaffolds were prepared for tissue engineering. Nano silver was loaded into the scaffold to improve its antibacterial ability and biomimetic Ca-P coatings were deposited on the scaffold surface to enhance its osteoconductivity. First, GO was prepared by the chemical oxidization of graphite. Secondly, nano-Ag loaded GO was prepared by chemical reducing Ag ions in GO solutions. Then, nano-Ag loaded GO solution was mixed with CS solution to form GO-CS gel. Chitosan (CS) and GO were crosslinked by electrostatic interactions between oxygen-containing functional groups of GO and NH2 groups of CS. The gel were freeze dried to produce nano-Ag loaded GO/CS hybrid porous scaffolds. Finally, the as-prepared scaffolds were immersed the into a supersaturated calcium phosphate solution (SCPS) for 7 days to deposite CaP coatings on the surface of the micropores. SEM images showed that nano-Ag uniformly distributed in the scaffold and the CaP covered most of the scaffold surfaces. In vitro cell culture and antimicrobial test indicated the biomimetic mineralized Ag-CS-GO scaffolds have good osteoconductivity and bactericidal ability.展开更多
文摘Graphene oxide (GO) reduced by Stachys lavandulifolia extract (SLE) was produced and characterised. The anti-corrosion behaviour of epoxy coatings containing GO and rGO nanosheets was investigated. FESEM-EDS, FT-IR, and Raman spectroscopy were used to examine the microstructure and chemical composition of the nanosheets and epoxy coatings. EIS experiment was used to explore the corrosion behaviour of the coatings. The O/C ratio for GO and rGO-SLE was found to be 2.5 and 4.5, indicating a decrease in the carbon content after the reduction of GO, confirming the adsorption of SLE onto the GO nanosheets. The successful reduction of GO in the presence of SLE particles was confirmed by disappearing the C=O peak and a significant decrease in the C-O-C bond intensity. The epoxy/rGO- SLE coatings exhibited the highest double-layer thickness and excellent corrosion resistance compared to neat epoxy and epoxy/GO coatings, emphasizing the significant role of rGO in enhancing the protective performance of epoxy coatings. The highest values for total charge transfer and film resistances and the inhibition efficiency were observed to be 6529 Ω·cm^(2) and 90%, respectively, for the epoxy/rGO-SLE coated steel plate. It was also found that the epoxy/0.15 wt.% rGO-SLE coating demonstrates the best corrosion resistance performance.
文摘Graphene oxide (GO) is a graphene derivatives that has oxygen-containing functional groups on the graphene basal plane, such as hydroxyl, carbonyl, epoxy and carboxyl groups. GO is considered as a promising material for biological applications owing to its excellent surface functionalizability, high specific suface area and good biocompatibility. In this study, GO/chitosan hybrid scaffolds were prepared for tissue engineering. Nano silver was loaded into the scaffold to improve its antibacterial ability and biomimetic Ca-P coatings were deposited on the scaffold surface to enhance its osteoconductivity. First, GO was prepared by the chemical oxidization of graphite. Secondly, nano-Ag loaded GO was prepared by chemical reducing Ag ions in GO solutions. Then, nano-Ag loaded GO solution was mixed with CS solution to form GO-CS gel. Chitosan (CS) and GO were crosslinked by electrostatic interactions between oxygen-containing functional groups of GO and NH2 groups of CS. The gel were freeze dried to produce nano-Ag loaded GO/CS hybrid porous scaffolds. Finally, the as-prepared scaffolds were immersed the into a supersaturated calcium phosphate solution (SCPS) for 7 days to deposite CaP coatings on the surface of the micropores. SEM images showed that nano-Ag uniformly distributed in the scaffold and the CaP covered most of the scaffold surfaces. In vitro cell culture and antimicrobial test indicated the biomimetic mineralized Ag-CS-GO scaffolds have good osteoconductivity and bactericidal ability.
