• Title/Summary/Keyword: Electro-chemistry

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Efficiency of Aluminum and Iron Electrodes for the Removal of Heavy Metals [(Ni (II), Pb (II), Cd (II)] by Electrocoagulation Method

  • Khosa, Muhammad Kaleem;Jamal, Muhammad Asghar;Hussain, Amira;Muneer, Majid;Zia, Khalid Mahmood;Hafeez, Samia
    • Journal of the Korean Chemical Society
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    • v.57 no.3
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    • pp.316-321
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    • 2013
  • Electrocoagulation (EC) technique is applied for the treatment of wastewater containing heavy metals ions such as nickle (Ni), lead (Pb) and cadmium (Cd) by using sacrificial anodes corrode to release active coagulant flocs usually aluminium or iron cations into the solution. During electrolytic reactions hydrogen gas evolve at the cathode. All the experiments were carried out in Batch mode. The tank was filled with synthetic wastewater containing heavy metals and efficiency of electro-coagulation in combination with aluminum and iron electrodes were investigated for removal of such metals. Several parameters, such as contact time, pH, electro-coagulant concentration, and current density were optimized to achieve maximum removal efficiency (%). The concentrations of heavy metals were determined by using Atomic Absorption Spectroscopy (AAS). It is found that the electro-coagulation process has potential to be utilized for the cost-effective removal of heavy metals from wastewater specially using iron electrodes in terms of high removal efficiencies and operating cost.

Fluorescent Probes for Analysis and Imaging of Monoamine Oxidase Activity

  • Kim, Dokyoung;Jun, Yong Woong;Ahn, Kyo Han
    • Bulletin of the Korean Chemical Society
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    • v.35 no.5
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    • pp.1269-1274
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    • 2014
  • Monoamine oxidases catalyze the oxidative deamination of dietary amines and amine neurotransmitters, and assist in maintaining the homeostasis of the amine neurotransmitters in the brain. Dysfunctions of these enzymes can cause neurological and behavioral disorders including Parkinson's and Alzheimer's diseases. To understand their physiological roles, efficient assay methods for monoamine oxidases are essential. Reviewed in this Perspective are the recent progress in the development of fluorescent probes for monoamine oxidases and their applications to enzyme assays in cells and tissues. It is evident that still there is strong need for a fluorescent probe with desirable substrate selectivity and photophysical properties to challenge the much unsolved issues associated with the enzymes and the diseases.

Theoretically-Guided Optimization of the Electro-Optic Activity of Organic Materials: 300 pm/V and Beyond

  • Sullivan, Phillip;Yiao, Li;Dalton, Larry
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.11-12
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    • 2006
  • Incorporation of chromophores into multi-chromophore-containing dendrimers is shown to lead to a significant enhancement in electro-optic activity. These results are reasonably well simulated by pseudo-atomistic Monte Carlo calculations that permit dendrimers to interpenetrate (entangle). Calculations also lead to the correct prediction of material densities. An even greater enhancement in electro-optic activity is observed when such dendrimer materials are doped with a second chromophore. This latter effect may reflect an Ising-lattice-type phenomenon where one chromophore impacts the ordering of the other and vice versa.

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Nano-Optical Investigation of Enhanced Field at Gold Nanosphere-Gold Plane Junctions

  • Ahn, Sung-Hyun;Park, Won-Hwa;Kim, Zee-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.28 no.12
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    • pp.2200-2202
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    • 2007
  • The local field distribution around gold nanosphere-gold plane junction has been studied using the finitedifference time-domain (FDTD) electrodynamics calculation procedure. We find that both the in-plane and out-of-plane polarized excitation produce enhanced field strong enough to explain the observed SERS activities of the junctions. Comparison with a simple dipole-image dipole model shows that the enhanced field primarily originates from the multipole-image multipole interaction, which indicates that the detailed fine-structures of the nanoparticles also play a significant role in the SERS activities as well.

Fully Substituted Ethylene as a New Class of Efficient Sky-Blue Emitting Materials for OLEDs

  • Kim, Soo-Kang;Park, Young-Il;Park, Jong-Wook;Kim, Kyung-Soo;Choi, Cheol-Kyu;Lee, Sang-Do
    • Journal of Information Display
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    • v.8 no.1
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    • pp.10-13
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    • 2007
  • We synthesized new blue and bluish green emitting materials by using fully substituted ethylene moieties. Multi-layered EL devices were fabricated with synthesized materials and evaluated in terms of emission color and luminescence efficiency. TBBPE[EML 2] device showed bluish-green CIE value of (0.236, 0.412) and 5.02cd/A at $10mA/cm^2$. BPBBPE[EML 3] device also showed sky-blue CIE value of(0.218, 0.355) and 2.31cd/A at $l0mA/cm^2$.

Physioelectrochemical Investigation of Electrocatalytic Activity of Modified Carbon Paste Electrode in Alcohol Oxidation as Anode in Fuel Cell

  • Shabani-Shayeh, Javad;Ehsani, Ali;Jafarian, Majid
    • Journal of the Korean Electrochemical Society
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    • v.17 no.3
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    • pp.179-186
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    • 2014
  • Methanol electro oxidation on the surface of carbon paste modified by $NiCl_2/6H_2O$ was studied in 1M NaOH by potentiostatic and potentiodynamic methods. Ni/C catalyst by the concentration of 5% Ni showed about twice higher electro catalytic activity than Ni metal. The amount of monolayer's on the surface of electrode is almost one order higher for Ni/C than Ni electrode. The kinetic parameters and the diffusion coefficient of methanol were derived from chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements.

Electro-optic Properties of a Guest-Host System Containing a Phenothiazine-based Chromophore: Effect of the Chromophore Density on the Macroscopic Optical Nonlinearity

  • Lee, Sang-Kyu;Cho, Min-Ju;Yoon, Hyuk;Lee, Seung-Hwan;Kim, Jae-Hong;Qing Zhang;Choi, Dong-Hoon
    • Macromolecular Research
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    • v.12 no.5
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    • pp.484-489
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    • 2004
  • We have prepared a phenothiazine-based nonlinear optical (NLO) chromophore that displays a fairly high microscopic nonlinearity through intramolecular charge transfer. The phenothiazine unit plays important roles of contributing its high electron donating ability and connecting the resonance pathway through a conjugative effect in the cyclized ring adjacent to the aromatic ring. Theoretical calculations and an absorption spectroscopic study provided useful information concerning the microscopic nonlinearity of the chromophores. We investigated the electro-optic (EO) properties of the guest-host systems in amorphous polycarbonate containing the synthesized chromophores at different concentrations under different poling temperatures. A real-time pole and probe method provided a much greater amount of information regarding how the EO properties can arise and how they can be optimized.

Electroluminescent Properties of Poly(10-octylphenothiazine-co-2',3',6',7'-tertrakis-octyloxy-9-spirobifluorene) of as an Emitting Material

  • Kang, Ji-Soung;Park, Jong-Wook;Lee, Ji-Hoon;Kim, Kyoung-Soo;Choi, Cheol-Kyu;Lee, Sang-Do;Kim, Sang-Wook
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1059-1062
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    • 2006
  • We report synthesis and properties of new phenothiazyl polymer derivatives, Poly(10-octyl-10Hphenothiazine-3,7-diyl)(POP), Poly(2',3',6',7'-tertrakis-octyloxy-9-spirobifluorene-2,7-diyl) (PTOSF), and their random copolymers, Poly(10-octylphenothiazine-co-2',3',6',7'-tertrakis-octyloxy-9-spirobifluorene) (POTOSF). PL emission of POP, PTOSF and POTOSF copolymer were found to be 480, 434 and 484nm, respectively. EL emission peak of double-layer EL device of POTOSF was at 494nm (bluish green).

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Electroluminesent Properties of Phenothiazyl Derivatives Having Aromatic Moieties

  • Kim, Soo-Kang;Kang, In-Nam;Park, Jong-Wook;Kim, Kyoung-Soo;Choi, Cheol-Kyu;Lee, Sang-Do;Kim, Sang-Wook
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1054-1058
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    • 2006
  • We report the synthesis and electroluminescent properties of new aromatic compounds as hole-transporting materials based on phenothiazine, such as 1,4-diphenothiazyl-benzene [DPtzB], 1,4-diphenothiazyl-xylene [DPtzX] and 9,10-diphenothiazyl-anthracene [DPtzA]. DPtzB thin film exhibited photoluminescence (PL) maximum emission peak and emission shoulder at 450 and 475nm, and maximum emission at 447nm without emission shoulder was found in DPtzX thin film. When DPtzA was excited by incident light of 359nm, DPtzA showed strong PL emission at 417nm and weak emission at 600nm. Luminance efficiency of DPtzB, DPtzX and DPtzA-based electroluminescence (EL) devices was 3.57, 3.46 and 0.47cd/A, and power efficiency of DPtzB, DPtzX and DPtzA-based EL devices was 1.48, 1.26 and 0.20lm/W.

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