• Title/Summary/Keyword: Hydroiodic acid reduction

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Determination of lead content in the plastic by ICP and AAS using HI reduction - PbSO4 dissolution method (HI 환원-PbSO4용해법을 이용한 ICP와 AAS에 의한 플라스틱 중의 납 정량 방법)

  • Lee, Hyun-Ja;Kim, Sang-Kyung;Lee, Se-Jin;Lee, Hyun-A
    • Analytical Science and Technology
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    • v.17 no.5
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    • pp.369-374
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    • 2004
  • Plastic was decomposed with nitric acid after being carbonized by sulfuric acid. Then excess sulfuric acid and nitric acid was removed by evaporating and drying. Precipitated $SO{_4}^{-2}$ ion of $PbSO_4$ was resolved itself into $H_2S$ by HI in hydrochloric acid and was volatilized. Then $Pb^{+2}$ was dissolved and was measured by AAS and ICP. The test for reproducibility using PVC-Pb standard material (690-34610mg/kg) was conducted and the accuracy was more than 99.9% compared with the estimated concentration. The precision by AAS was 99.8% and that of ICP was 99.9%.

Flexible and Transparent Plastic Electrodes Composed of Reduced Graphene Oxide/Polyaniline Films for Supercapacitor Application

  • Sarker, Ashis K.;Hong, Jong-Dal
    • Bulletin of the Korean Chemical Society
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    • v.35 no.6
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    • pp.1799-1805
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    • 2014
  • In this article, we described about the preparation and electrochemical properties of a flexible energy storage system based on a plastic polyethylene terephthalate (PET) substrate. The PET treated with UV/ozone was fabricated with multilayer films composed of 30 polyaniline (PANi)/graphene oxide (GO) bilayers using layer-by-layer assembly of positively charged PANi and negatively charged GO. The conversion of GO to the reduced graphene oxide (RGO) in the multilayer film was achieved using hydroiodic acid vapor at $100^{\circ}C$, whereby PANi structure remained nearly unchanged except a little reduction of doping state. Cyclic voltammetry and charge/discharge curves of 30 PANi/RGO bilayers on PET substrate (shorten to PANi-$RGO_{30}$/PET) exhibited an excellent volumetric capacitance, good cycling stability, and rapid charge/discharge rates despite no use of any metal current collectors. The specific capacitance from charge/discharge curve of the PANi-$RGO_{30}$/PET electrode was found to be $529F/cm^3$ at a current density of $3A/cm^3$, which is one of the best values yet achieved among carbon-based materials including conducting polymers. Furthermore, the intrinsic electrical resistance of the PANi-$RGO_{30}$/PET electrodes varied within 20% range during 200 bending cycles at a fixed bend radius of 2.2 mm, indicating the increase in their flexibility by a factor of 225 compared with the ITO/PET electrode.