• Title/Summary/Keyword: Korea Environment Institute

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Preparation of sulfonated reduced graphene oxide by radiation-induced chemical reduction of sulfonated graphene oxide

  • Jung, Chang-Hee;Hong, Ji-Hyun;Jung, Jin-Mook;Hwang, In-Tae;Jung, Chan-Hee;Choi, Jae-Hak
    • Carbon letters
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    • v.16 no.1
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    • pp.41-44
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    • 2015

  • We report the preparation of sulfonated reduced graphene oxide (SRGO) by the sulfonation of graphene oxide followed by radiation-induced chemical reduction. Graphene oxide prepared by the well-known modified Hummer's method was sulfonated with the aryl diazonium salt of sulfanilic acid. Sulfonated graphene oxide (SGO) dispersed in ethanol was subsequently reduced by ${\gamma}$-ray irradiation at various absorbed doses to produce SRGO. The results of optical, chemical, and thermal analyses revealed that SRGO was successfully prepared by ${\gamma}$-ray irradiation-induced chemical reduction of the SGO suspension. Moreover, the electrical conductivity of SRGO was increased up to 2.94 S/cm with an increase of the absorbed dose.

  • https://doi.org/10.5714/CL.2015.16.1.041 인용 PDF KSCI KPUBS HTML

Total Phenolic Contents and Biological Activities of Korean Seaweed Extracts

  • Kim, So-Jung;Woo, Seon-Ock;Yun, Hee-Young;Yum, Seung-Shic;Choi, Eun-Seok;Do, Jeong-Ryong;Jo, Jin-Ho;Kim, Dong-Giun;Lee, Suk-Chan;Lee, Taek-Kyun
    • Food Science and Biotechnology
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    • v.14 no.6
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    • pp.798-802
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    • 2005

  • Crude extracts of thirty seaweeds collected in Korea were obtained using 50% ethanol, and total phenolic contents and antioxidant activities were compared. Two brown algae, Ecklonia cava (E. cava) and Sargassum siliquastrum (S. siliquastrum), showing high antioxidant activity based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity and superoxide anion radical scavenging activity were further investigated for their inhibitory effects on tyrosinase activity. The E. cava extract had the highest total phenolic content among the seaweeds extracts. Total phenolic contents were strongly correlated with antioxidant activity in the thirty seaweed extracts ($R^2\;=\;0.9169$). The E. cava and S. siliquastrum extracts exhibited higher inhibition to tyrosinase activity than butylated hydroxytoluene (BHT) and epigallocatechin gallate (EGCG).

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