• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.153-154
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• 2017

Graphene is a nanomaterial and is known to have very high mechanical strength, thermal and electrical properties. However, graphene is known to be difficult to disperse among carbon-based materials due to van der Waals force. In this study, to solve the dispersion problem of graphene nanoplatelet, oxidized graphene nanoplatelet was prepared by oxidizing GNP in nitric acid. The prepared GO was dispersed in ethanol and distilled water before incorporation into the epoxy paint to confirm dispersibility. In addition, GNP/Epoxy and GO/Epoxy tensile specimens were prepared by mixing GNP and GO at 0.1, 0.3, 0.5 and 1.0 wt.% In epoxy coatings and tensile stress-strain characteristics were investigated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.31-32
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• 2019

In this study, oxidized graphene nanoplatelet(GO) was prepared by oxidizing graphene nanoplatelet(GNP) with nitric acid in order to solve the problem of dispersion of GNP, one of nano materials. GNP/Epoxy and GO/Epoxy paint were prepared by mixing GNP, GO with 0.1, 0.3, 0.5 and 1.0 wt.% in epoxy paint and the mechanical properties were evaluated. As a result, GNP/Epoxy and GO/Epoxy paints showed better mechanical properties than Neat Epoxy which did not incorporate GNP, GO. Especially, when 0.3 wt.% of GO was incorporated into epoxy resin, it showed higher tensile strength than Neat Epoxy. It was confirmed that acid treatment of GNP was effective in improving the mechanical properties of epoxy paint. However, graphene material was found that it was not effective in improving the bond performance of the epoxy paint.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.181-182
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• 2020

In this study, oxidized graphene nanoplatelet(GO) was prepared by oxidizing graphene nanoplatelet(GNP) with nitric acid in order to solve the problem of dispersion of GNP, one of nano materials. GNP/Epoxy and GO/Epoxy were prepared by mixing GNP, GO with 0.1, 0.3, 0.5 and 1.0 wt.% in epoxy and the mechanical properties, bond performance were evaluated. As a result, GNP/Epoxy and GO/Epoxy showed higher tensile strength than Neat Epoxy at the 0.1, 0.3 wt.%. Especially, when 0.1 wt.% of GO was incorporated into epoxy resin, it showed highest tensile strength. It was confirmed that acid treatment of GNP was effective in improving the mechanical properties of epoxy paint. However, graphene material was found that it was not effective in improving the bond strength of the epoxy paint.

• Journal of the Korea Institute of Building Construction
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• v.23 no.5
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• pp.547-558
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• 2023

This research delves into the fabrication of an ultra-high-strength concrete, enriched with oxidized graphene nanoplatelet(GO) and hollow glass powder(HGP), notably eschewing the conventional inclusion of silica fume(SF). The primary objective was to scrutinize the autogenous shrinkage characteristics of this innovative formulation. It was discerned that the NewMix specimen, which incorporated the cGO(sourced from Company C) and HGP, and intentionally bypassed SF, showcased a commendable 13% reduction in autogenous shrinkage relative to the benchmark(Ref) specimenthat incorporated SF. Moreover, the proclivity for crack formation owing to autogenous shrinkage in the NewMix was observed to manifested by NewMix at the juncture of cracking emerged as the apex value. Attributed to the expansive specific surface area and exemplary dispersibility of cGO, it was postulated that the concrete's pore structure benefitted from enhanced infill, leading to a reduction in autogenous shrinkage. Additionally, the cGO integration fortified the concrete's resistance to crack initiation. Consequently, such an enhancement is posied to be pivotal in mitigating crack propagation resulting from autogenous shrinkage in ultra-high-strength concrete.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.465-471
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• 2017

In this study, oxidized graphene nanoplatelet(GO) was prepared by oxidizing graphene nanoplatelet(GNP) with nitric acid in order to solve the problem of dispersion of GNP, one of nano materials. The surface chemical composition of the prepared GO was analyzed by fourier transform infrared spectroscopy(FT-IR) before incorporation into the epoxy paint, and the dispersibility in the solvent was confirmed. Meanwhile, GNP/Epoxy and GO/Epoxy paint were prepared by mixing GNP, GO with 0.1, 0.3, 0.5 and 1.0wt.% in epoxy paint and the mechanical properties were evaluated. As a result, GNP/Epoxy and GO/Epoxy paints showed better mechanical properties than Neat Epoxy which did not incorporate GNP, GO. Especially, when 0.3wt.% of GO was incorporated into epoxy resin, it showed higher tensile strength than Neat Epoxy. It was confirmed that acid treatment of GNP was effective in improving the mechanical properties of epoxy paint.

• Journal of the Korea Institute of Building Construction
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• v.23 no.4
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• pp.381-392
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• 2023

This research scrutinizes the mechanical characteristics of ultra-high strength concrete using oxide graphene nanoplatelet(GO) and hollow glass powder(HGP). The investigation covered various mechanical attributes, including workability, compression strength, tensile strength, water resistance, and the internal microstructure of standard concrete. Our findings reveal that workability experiences a significant improvement with the incorporation of a minimal amount of HGP, and an increase was also observed in tensile strength and water resistance. It was confirmed that cGO(C company GO) and HGP demonstrated commendable dispersion and the pore volume exhibited a reduction of more than 20%. The potential of cGO and HGP to substitute silica fume(SF) was also explored. Consequently, it was found that both workability and mechanical properties were enhanced in the absence of SF when cGO and HGP were used. This finding implies that the utilization of these novel materials could potentially modify conventional methods of concrete manufacturing.