Volatile organic compounds(VOCs) are toxic carcinogenic compounds found in wastewater. VOCs require rapid removal because they are easily volatilized during wastewater treatment. Electrochemical advanced oxidation processes(EAOPs) are considered efficient for VOC removal, based on their fast and versatile anodic electrochemical oxidation of pollutants. Many studies have reported the efficiency of removal of various types of pollutants using different anodes, but few studies have examined volatilization of VOCs during EAOPs. This study examined the removal efficiency for VOCs (chloroform, benzene, trichloroethylene and toluene) by oxidization and volatilization under a static stirred, aerated condition and an EAOP to compare the volatility of each compound. The removal efficiency of the optimum anode was determined by comparing the smallest volatilization ratio and the largest oxidization ratio for four different dimensionally stable anodes(DSA): Pt/Ti, IrO2/Ti, IrO2/Ti, and IrO2-Ru-Pd/Ti. EAOP was operated under same current density (25 mA/cm2) and electrolyte concentration (0.05 M, as NaCl). The high volatility of the VOCs resulted in removal of more than 90% within 30 min under aerated conditions. For EAOP, the IrO2-Ru/Ti anode exhibited the highest VOC removal efficiency, at over 98% in 1 h, and the lowest VOC volatilization (less than 5%). Chloroform was the most recalcitrant VOC due to its high volatility and chemical stability, but it was oxidized 99.2% by IrO2-Ru/Ti, 90.2% by IrO2-Ru-Pd/Ti, 78% by IrO2/Ti, and 75.4% by Pt/Ti anodes The oxidation and volatilization ratios of the VOCs indicate that the IrO2-Ru/Ti anode has superior electrochemical properties for VOC treatment due to its rapid oxidation process and its prevention of bubbling and volatilization of VOCs.

Indirect oxidation using chlorine species oxidizing agents is often effective in wastewater treatment using an electrochemical oxidation process. When chlorine ions are contained in the wastewater, oxidizing agents of various chlorine species are produced during electrolysis. In a ballast water management system, it is also used to treat ballast water by electrolyzing seawater to produce a chlorine species oxidizer. However, ballast water in the brackish zone and some wastewater has a low chlorine ion concentration. Therefore, it is necessary to study the chlorine generation current efficiency at various chlorine concentration conditions. In this study, the chlorine generating current efficiency of a boron-doped diamond(BDD) electrode and insoluble electrodes are compared with various chloride ion concentrations. The results of this study show that the current efficiency of the BDD electrode is better than that of the insoluble electrodes. The chlorine generation current efficiency is better in the order of BDD, MMO(mixed metal oxide), Ti/RuO2, and Ti/IrO2 electrodes. In particular, when the concentration of sodium chloride is 10 g/L or less, the current efficiency of the BDD electrode is excellent.

In anion exchange membrane fuel cells, Pd nanoparticles are extensively studied as promising non-Pt catalysts due to their electronic structure similar to Pt. In this study, to fabricate Pd nanoparticles well dispersed on carbon support materials, we propose a synthetic strategy using mixed organic ligands with different chemical structures and functions. Simultaneously to control the Pd particle size and dispersion, a ligand mixture composed of oleylamine(OA) and trioctylphosphine(TOP) is utilized during thermal decomposition of Pd precursors. In the ligand mixture, OA serves mainly as a reducing agent rather than a stabilizer since TOP, which has a bulky structure, more strongly interacts with the Pd metal surface as a stabilizer compared to OA. The specific roles of OA and TOP in the Pd nanoparticle synthesis are studied according to the mixture composition, and the oxygen reduction reaction(ORR) activity and durability of highly-dispersed Pd nanocatalysts with different particles sizes are investigated. The results of this study confirm that the Pd nanocatalyst with large particles has high durability compared to the nanocatalyst with small Pd nanoparticles during the accelerated degradation tests although they initially indicated similar ORR performance.

We have synthesized new alkylated indenopyrazine homopolymer and its copolymer having an alkylated spirofluorene moiety. Poly(6,6,12,12-(Tetra-2-ethylhexyl)-6,12-Dihydrodiindeno[1,2-b:1,2-e]pyrazine-2,8-diyl) [PEHIP] and Poly(6,6,12,12-(tetra-2-ethylhexyl)-6,12-dihydrodiindeno[1,2-b:1,2-e]pyrazine-co-20,30,60,70-tertrakis-octyloxy-9-spirofluorene) [PEHIPSF] were polymerized by using Yamamoto reaction. PEHIP and PEHIPSF showed the PL maximum values of 470 nm and 454 nm in PL spectra. The PEHIPSF was fabricated into an EL device and it exhibited the EL maximum value of 463 nm.

The electrochemical properties of poly(a-methylbenzyl dipropargylamine) was studied by cyclic voltametry. Poly(a-methylbenzyl dipropargylamine) was prepared by the cyclopolymerization of a-methylbenzyl dipropargylamine in high yield. The photoluminescence peaks of the present polymer was observed at 443nm corresponding to the photon energy of 2.80 eV. The cyclovoltamograms of the polymer exhibited the irreversible electrochemical behaviors between the doping and undoping peaks. It was found that the kinetics of the redox process of poly(MBDA) might be mainly controlled by the electron transfer process from the experiment of the oxidation current density of poly(MBDA) versus the scan rate.

Ion exchange membranes (IEMs) have been widely employed in various electrochemical processes for water treatment and energy conversion. Their intrinsic properties such as electrical resistance and permselectivity are the key parameters dominating the efficiency of the electrochemical processes. The cost-effectiveness of the IEMs should also be considered for successful commercialization of the electrochemical membrane processes. In this work, we have investigated the optimum design parameters of the cost-effective IEMs for successful application to various electrochemical membrane processes. (This work was supported by the Technology Innovation Program funded by the Korea government (MOTIE) (No. 10047796).).

Saline water electrolysis (SWE) is an electrochemical technology to directly generate valued chemicals such as chlorine gas (Cl2), hydrogen (H2), and sodium hydroxide (NaOH) by applying electric energy. The key materials in SWE are cation exchange membranes with high selectivity to sodium ions under chemically harsh SWE conditions. The representative SWE membranes are perfluorinated double layered membranes composed of perfluorinated sulfonic acid layer and carboxylic acid layer to transport sodium ions rapidly and to prevent the passage of hydroxide ions, respectively. The commercially available membranes are, however, suffering from delamination issues occurring in their interface. In this presentation, delamination-free membrane fabrication processes will be addressed.

To formulate folate receptor (FR)-specific graphene-based electrochemical electrodes, a folic acid (FA) derivative attached with two pyrene molecules on the glutamate tail of FA was synthesized. The resulting pyrene-functionalized FA (FA-Py) presented the spontaneous noncovalent binding on chemically reduced graphene oxides (rGO) through an π-π interaction. Ultrathin morphology, high water-resistance, and preservation of intact FR-specific pteroates from the rGO/FA-Py assembly allow this assembly to be exploited as robust and FR-specific electrochemical electrode materials. The limits of detecting rGO/FA-Py modified electrodes were found to be as low as 3.07 nM in FR concentrations in cyclic voltammetry analysis.

Using a high pressure homonizer, we report on the electrochemical performance of Li4Ti5O12(LTO) particles manufactured as anode active material for lithium ion battery. High-pressure synthesis processing is performed under conditions in which the mole fraction of Li/Ti is 0.9, the synthesis pressure is 2,000 bar and the numbers of passings-through are 5, 7 and 10. The observed X-ray diffraction patterns show that pure LTO is manufactured when the number of passings-through is 10. It is found from scanning electron microscopy analysis that the average size of synthesized particles decreases as the number of passings-through increases. LiCoO2-based active cathode materials are used to fabricate several coin half/full cells and their battery characteristics such as lifetime, rate capability and charge transfer resistance are then estimated, revealing quite good electrochemical performance of the LTO particles as an effective anode active material for lithium secondary batteries.