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41.
Electrochemical cell current requirements for toxic organic waste destruction in Ce(IV)-mediated electrochemical oxidation process 总被引:1,自引:0,他引:1
Vasily V. Kokovkin Sang Joon Chung Subramanian Balaji Manickam Matheswaran Il-Shik Moon 《Korean Journal of Chemical Engineering》2007,24(5):749-756
The electrochemical cell for cerium oxidation and reactor for organic destruction are the most important operation units for
the successful working mediated electrochemical oxidation (MEO) process. In this study, electrochemical cells with DSA electrodes
of two types, single stack and double stack connected in series, were used. The performances towards the electrochemical generation
of Ce(IV) in nitric acid media at 80 °C were studied. The current-voltage curves and cerium electrolysis kinetics showed the
dependence on number of cell stacks needed to be connected in series for the destruction of a given quantity of organic pollutant.
The presence of an optimum region for Ce(III) oxidation with a contribution of oxygen evolution, especially at low Ce(III)
concentration (high conversion ratios), was found. The cells were applied for the Ce(IV) regeneration during the organic destruction.
The cell and reactor processes were fitted in a simple model proposed and used to calculate the current needed in terms of
Ce(III) oxidation rate and the number of cell stacks required for maintaining Ce(IV)/Ce(III) ratio at the same level during
the organic destruction. This consideration was based on the kinetic model previously developed by us for the organic destruction
in the MEO process. 相似文献
42.
A new chelating fabrics are synthesized by radiation induced grafting of acrylonitrile (AN) onto polypropylene nonwoven fabrics (PP fabrics) and subsequent conversion of cyano to an imine by reaction with ethylene diimine (EDA). Influence of various parameters such as initial concentration, pH and adsorption time on the adsorption amount for palladium ions was investigated. It was found that adsorbent achieved excellent adsorption performance in palladium ion removal in the pH range of 1.88–5.70. The adsorption amount of ions increased with shaking time and initial concentration of palladium ions. The grafted and aminated fabrics were characterized by FT‐IR, TGA and SEM. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
43.
Baik Joon Hyun Yim Sung Dae Nam In-Sik Mok Young Sun Lee Jong-Hwan Cho Byong K. Oh Se H. 《Topics in Catalysis》2004,30(1-4):37-41
Topics in Catalysis - Among the catalysts screened, Cu-ion exchanged ZSM5 zeolite exhibited the highest NO removal activity, particularly at low reaction temperatures below 200 °C,... 相似文献
44.
Due to the numerous applications of nanofluids, investigating and understanding of thermophysical properties of nanofluids
has currently become one of the core issues. Although numerous theoretical and numerical models have been developed by previous
researchers to understand the mechanism of enhanced heat transfer in nanofluids; to the best of our knowledge these models
were limited to the study of either thermal conductivity or convective heat transfer of nanofluids. We have developed a numerical
model which can estimate the enhancement in both the thermal conductivity and convective heat transfer in nanofluids. It also
aids in understanding the mechanism of heat transfer enhancement. The study reveals that the nanoparticle dispersion in fluid
medium and nanoparticle heat transport phenomenon are equally important in enhancement of thermal conductivity. However, the
enhancement in convective heat transfer was caused mainly due to the nanoparticle heat transport mechanism. Ability of this
model to be able to understand the mechanism of convective heat transfer enhancement distinguishes the model from rest of
the available numerical models. 相似文献
45.
Jin Woo Bae Tae Uk Yang Gi Joon Nam Gun Joo Lee Byeong-Uk Nam Jae Young Jho 《Polymer Bulletin》2011,67(4):729-740
Ethylene vinylacetate (EVA) copolymer-based nanocomposites with maleic anhydride-grafted ethylene-vinylacetate (EVAgMA) and
organically modified clay (o-clay) were prepared in a twin screw extruder by following a two-step melt compounding method.
EVAgMA/o-clay masterbatches with various clay contents up to 50 wt% were examined, after which the masterbatch with the highest
clay content was melt compounded with EVA for the preparation of EVA/o-clay nanocomposites containing specific amounts of
clay. Further morphological dispersion of the clay particles by highly polar EVA and shearing was confirmed in the EVA/o-clay
nanocomposites by X-ray diffraction (XRD) and transmission electron microscopy (TEM). These morphologies led to increased
thermal properties in air as well as a considerable decrease in heat release rate (HRR). EVA/o-clay/MDH nanocomposites were
also prepared using a high clay-bearing masterbatch to confirm the synergistic flame retardancy of clay as a co-additive in
EVA/MDH composites. EVA/o-clay/MDH nanocomposites prepared by substituting o-clay for MDH showed significantly lower and wider
HRR during combustion compared to EVA/MDH composite. 相似文献
46.
A method is presented for significantly reducing the interfacial contact resistance of single-walled carbon nanotube (SWCNT) interconnects test-structures. Conventional lithographic cleaning steps are insufficient for complete removal of lithographic residues in SWCNT networks, leading to large interfacial contact resistance. Using improved purification procedures and controlled developing time, the interfacial contact resistance between SWCNTs and contact electrodes of Ti/Au were found to reach values below 2% of the overall resistance in two-probe test-structures of SWCNTs, demonstrating the importance of cleaning lithographic residues from the surface of SWCNTs before the fabrication of metal electrodes. These low-resistance contacts are quite stable over a large temperature range, and represent a step towards the implementation of SWCNTs as future interconnects. 相似文献
47.
Carbon nanotube/Co<Subscript>3</Subscript>O<Subscript>4</Subscript> composite for air electrode of lithium-air battery 总被引:1,自引:0,他引:1
A carbon nanotube [CNT]/Co3O4 composite is introduced as a catalyst for the air electrode of lithium-air [Li/air] batteries. Co3O4 nanoparticles are successfully attached to the sidewall of the CNT by a hydrothermal method. A high discharge capacity and a low overvoltage indicate that the CNT/Co3O4 composite is a very promising catalyst for the air electrode of Li/air batteries. 相似文献
48.
Taeseon Hwang Joon Suk Oh Jung-Pyo Hong Gi-Yong Nam Ah-Hyun Bae Sang-Ik Son Geun-Ho Lee Hak-Kyung Sung Youngkwan Lee Jae-Do Nam 《Carbon》2012,50(2):612-621
Few-layer graphene (FLG) was investigated as an electrically-conductive interleaf layer for one-step electroplating and patterning of metal on nonconductive polymer substrates without using multiple and toxic pretreatment processes in traditional electroplating. An individual FLG (5–10 nm of thickness with 6.4% of oxygen content) was obtained by expanding graphite with microwave followed by exfoliating the expanded graphite with sonication in N-methyl-pyrrolidone. Stacking FLG in the in-plane direction, a robust FLG film was obtained by the vacuum-assisted filtering and drying methods, and transferred to a polyethylene terephthalate (PET) substrate via an intermediate transfer to the water surface. The sheet resistance of the FLG film on the PET substrate was 0.9 kΩ/sq with a thickness of 80 nm and the root-mean-square roughness of 29 nm. In the electroplating of nickel on the FLG film, hemisphere-shape metal seeds appeared in the early stage of electroplating and they subsequently grew up to 200–480 nm, which became connected to form a continuous nickel layer. The thickness of the continuous nickel layer increased linearly with electroplating time. The developed electroplating method demonstrated its capability of selective patterning on nonconductive substrates using a simple masking technique. 相似文献
49.
Piezoelectric and dielectric properties of (K0.44Na0.52Li0.04)(Nb0.86Ta0.10Sb0.04)O3–PVDF composites
Jeong-Hyeon Seol Jae Shin Lee Han-Na Ji Yun-Po Ok Gyoung Pyo Kong Ki-Soo Kim Chang Yoon Kim Weon-Pil Tai 《Ceramics International》2012
(Li, Ta, Sb) modified sodium potassium niobate/poly(vinylidene fluoride) [(K0.44Na0.52Li0.04)(Nb0.86Ta0.10Sb0.04)O3–PVDF] 0-3 composites were prepared by a cold press technique, and their piezoelectric and dielectric properties were characterized. All composites exhibited good dispersion of ceramic particles in the polymer matrix. The piezoelectric and dielectric constants were found to be enhanced as the concentration of sodium potassium niobate increases. Even though the process is simple, the composite prepared in this study showed better piezoelectric and dielectric properties than PZT–polymer composites. At room temperature, a (K0.44Na0.52Li0.04)(Nb0.86Ta0.10Sb0.04)O3–PVDF (7:3) composite revealed a relative dielectric constant, ?r = 166, piezoelectric constant, d33 = 33 pC/N and coercive field, Ec = 5 kV/cm. 相似文献
50.
Wonghil Chang GeumHee Chae So Ra Jang Jihye Shin Byoung Joon Ahn 《Journal of Industrial and Engineering Chemistry》2012,18(2):581-585
Palladium catalysts, Pd/MCM-41 and Pd/SBA-15 were prepared by impregnation of an aqueous solution of [Pd(NH3)4]Cl2 on MCM-41 and SBA-15. Palladium contents of Pd/MCM-41 and Pd/SBA-15 are 8.4% and 8.7%, respectively. It has been shown that these catalysts are very suitable to microwave-assisted Suzuki reactions under solvent-free condition. It is also found that the base additives for this reaction are K2CO3, Cs2CO3 or CsF. Thus, phenylboronic acid and phenyl iodide with Pd/MCM-41 produce biphenyl by microwave irradiation for 10 min in 97.4% yield. Phenyl bromide, instead of phenyl iodide, also proceeds the reaction with phenylboronic acid using Pd/MCM-41 or Pd/SBA-15 yielding biphenyl by microwave irradiation for 10 min in excellent yield. Whereas the reaction of phenyl chloride with phenylboronic acid gives poor yield in same condition. Various aryl iodides and aryl bromides are tested. In this paper our recent results of microwave-assisted Suzuki reaction using Pd/MCM-41 and Pd/SBA-15 under solvent-free condition are described. 相似文献