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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Korean Chemical Engineering Research
Journal Basic Information
Journal DOI :
The Korean Institute of Chemical Engineers
Editor in Chief :
KIM JAE JEONG
Volume & Issues
Volume 45, Issue 6 - Dec 2007
Volume 45, Issue 5 - Oct 2007
Volume 45, Issue 4 - Aug 2007
Volume 45, Issue 3 - Jun 2007
Volume 45, Issue 2 - Apr 2007
Volume 45, Issue 1 - Feb 2007
Selecting the target year
Design of Nanocomposite Photocatalysts for Solar Hydrogen Production
Jang, Jum-Suk ; Kim, Hyun-Gyu ; Lee, Jae-Sung ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 415~423
Photocatalytic water splitting (PWS) is the most promising technology to produce H2 energy directly from renewable water and solar light. In spite of the remarkable progress made in the last decade, there are still many technical challenges remaining particularly in finding new photocatalytic materials with high efficiency and durability. This article discusses the application of nanocomposite materials in search of new photocatalytic materials for solar hydrogen production from water. It has been demonstrated that smart combination and modification of known materials and functions could be fruitful approach for the purpose.
Biodiesel Production Technology and Its Fuel Properties
Hong, Yeon-Ki ; Hong, Won-Hi ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 424~432
Biodiesel is gaining more attractive due to its eco-friendly and the fact that it is prepared from renewable sources. It is monoalkyl esters of long chain fatty acids derived from vegetable oils and animal fats via transesterification reaction with alcohol in the presence of catalyst. This paper will review briefly (1) the effect of reaction conditions such as catalyst type, amount of free fatty acid and moisture, molar ratio of alcohol and oil, alcohol type, reaction temperature and time and stirring intesity, (2) downstream process of biodiesel after transesterification reaction, and (3) potentialities of biodiesel as an alternative fuel based on its properties in diesel engines.
Stability Characteristics of Sn Species Behavior on Surface of a Sn-modified Pt Electrode for Electrolytic Reduction of Nitrate Ion
Kim, Kwang-Wook ; Kim, Seong-Min ; Kim, Yeon-Hwa ; Lee, Eil-Hee ; Jee, Kwang-Yong ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 433~441
work investigated the stability of a Sn-modified Pt electrode, which was used for reduction of nitrate,eeffects of the solutions in which the electrode was used and the potential applied to the electrode on the electrochemical andmetallurgical behaviors of Sn on Pt were studied. The Sn of freshly- prepared modified-Sn Pt electrode existed as Snhydroxide form, which brought about an easy loss of the electro-activity of the electrode even staying in water, especially inacid solution. When the Sn-modified Pt electrode was used for the reduction of nitrate, the electro-activity of the electrodewas afected depending on the potential applied to the electrode. When a more negative potential than the redox equilib-rium potential between Sn(OH)2 and Sn was applied to the electrode, the Sn hydroxide was converted to Sn that could dif-fused into Pt, which leaded to the loss of electro-activity of the electrode as well. The solid difusion of Sn increasedfavorable to maintaining the integrity of the electrode during the reduction of nitrate than the Sn-adsorbed Pt electrode pre-pared in the under-potential deposition way.
Preparation of Hard Coating Solutions using Colloidal Silica and Glycidoxypropyl Trimethoxysilane by the Sol-Gel Method
Kim, Dae-Hyun ; Song, Ki-Chang ; Chung, Jae-Shik ; Lee, Bum-Suk ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 442~447
In order to improve the surface hardness of transparent plastic films, organic-inorganic hybrid coating solutions were synthesized by the sol-gel method. The coating solutions were prepared by adding GPTMS (glycidoxypropyl trimethoxysilane) to a colloidal silica (12 nm) suspension. PC(polycarbonate) substrates were dipped into the coating solutions and dried at room temperature for 10 min before being cured at 80 ℃ for 30 min. The effect of the solution pH and GPTMS content was investigated on the properties of coating films. The pencil hardness and adhesion to substrates of the coating films, prepared at acidic condition (pH 4), showed better properties than those at neutral or basic conditions. Also, the pencil hardness and adhesion to substrates of the coating films increased with increasing GPTMS content.
Hydrothermal Synthesis and Characterization of
Park, Jung-Hoon ; Park, Sang-Do ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 448~454
In this study, spherical pre-BaTiO3 particles are prepared by gelation and aging process in autoclave without catalysts. The (Ba-Ti) gel used as a starting material was prepared by aging mixtures of titanyl acylate with barium acetate aqueous solution([glacial acetic acid (AcOH)]/[titanium isopropoxide (TIP)] 4, [barium acetate]/[TIP] 1) at 45°C for 48 hrs. XRD and SEM results for the (Ba-Ti) gel sample at aging process showed that the gel was formed via aggregation of the fine particles. It seems to be the primary particles of bulk (Ba-Ti) gel amorphous, but the spatial arrangement of barium and titanium in the (Ba-Ti) gel is similar to that in crystalline BaTiO3 particles. From XRD and FT-IR, spectroscopy analysis it was found that the crystal structure of the prepared particles continuously transformed from amorphous to tetragonal as the calcination temperature increased, and crystallized spherical cubic and tetragonal BaTiO3 powder obtained at the very low calcination temperature between 500℃ and 900°C after 1 hrs of heat treatment respectively. According to BET analysis result, final particle have pore structure of ink bottle shape which is produced by aggregation of fine spherical particles with surface area of 280㎡/g and average pore size of 13㎚.
Plasma Catalytic Methane Conversion over Sol-gel Derived Pt/
Catalyst in a Dielectric-barrier Discharge Reactor
Kim, Seung-Soo ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 455~459
catalytic methane conversion was carried out in the presence of sol-gel derived Pt/TiO2 catalystswithin a dielectric-barrier discharge (DBD) reactor. Plasma-assisted reduction (PAR) was applied to reduce the preparedPt/TiO2 catalysts in DBD reactor, and prepared catalysts were successively reduced by PAR within 20 min irrespectiveof the Pt loading and the calcination temperature. The highest methane conversion was 40% when 3 wt% Pt/TiO2 and5 wt% Pt/TiO2 catalysts were used after calcination at 60oC. The selectivities of light alkanes (C2H6, C3H8, C4H10)were highly increased when Pt/TiO2 catalysts were used in DBD reactor
Photo- and Sonic Degradation of Endosulfans(
, and sulfate) in Aqueous Solution
Kwon, Sung-Hyun ; Kim, Jong-Hyang ; Cho, Dae-Chul ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 460~465
Endosulfan-α endosulfan-β and endosulfan-sulfate, which are classified as pesticides, were degraded by use of UV energy and ultrasonic irradiation. The degradation residuals were analysed by gas chromatography with an electron capture detector and TOC (total oragnic carbon) analysis. The reactions were conducted in a quartz annular reactor equipped with a low pressure mercury multilamp (8Wx2) and a sonic generator. All the aqueous solutions were concentrated as 10 mg/L initially. Endosulfans were degraded each to result in 48.2% (α, 50.0% (β and 76.5% (sulfate) of removal efficiency by UV energy, and 66.9% (α, 55.8% (β and 72.7% (sulfate) by ultrasonic irradiation, respectively. In contrast to the results of the single-component solutions, degradation of the endosulfan-sulfate was greatly suppressed to result in the lowest degradation rate and removal efficiency in the three-component solutions. This finding suggests that there should be a reversible reaction with a substantially low equilibrium constant between endosulfan-αor -β and -sulfate in the coexistence of the three endosulfans. TOC data showed the endosulfans were decomposed by 20%~40% toward complete mineralization, producing a quantity of intermediates induced by the radical reactions. We found that all the decay reactions considered in this study nicely fell into pseudo first-order rate.
A Study on Wafer-Level 3D Integration Including Wafer Bonding using Low-k Polymeric Adhesive
Kwon, Yong-Chai ; Seok, Jong-Won ; Lu, Jian-Qiang ; Cale, Timothy ; Gutmann, Ronald ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 466~472
A technology platform for wafer-level three-dimensional integration circuits (3D-ICs) is presented, and that uses wafer bonding with low-k polymeric adhesives and Cu damascene inter-wafer interconnects. In this work, one of such technical platforms is explained and characterized using a test vehicle of inter-wafer 3D via-chain structures. Electrical and mechanical characterizations of the structure are performed using continuously connected 3D via-chains. Evaluation results of the wafer bonding, which is a necessary process for stacking the wafers and uses low-k dielectrics as polymeric adhesive, are also presented through the wafer bonding between a glass wafer and a silicon wafer. After wafer bonding, three evaluations are conducted; (1) the fraction of bonded area is measured through the optical inspection, (2) the qualitative bond strength test to inspect the separation of the bonded wafers is taken by a razor blade, and (3) the quantitative bond strength is measured by a four point bending. To date, benzocyclobutene (BCB), FlareTM, methylsilsesquioxane (MSSQ) and parylene-N were considered as bonding adhesives. Of the candidates, BCB and FlareTM were determined as adhesives after screening tests. By comparing BCB and FlareTM, it was deduced that BCB is better as a baseline adhesive. It was because although wafer pairs bonded using FlareTM has a higher bond strength than those using BCB, wafer pairs bonded using BCB is still higher than that at the interface between Cu and porous low-k interlevel dielectrics (ILD), indicating almost 100% of bonded area routinely.
Synthesis of Ag-Hydroxyapatite Antibiotic Material by Coprecipitation Method
Jang, Kwang-Kyu ; Shin, Hun-Yong ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 473~478
Antibiotic composite was synthesized by coprecipitation of silver nitrate into hydroxyapatite. Adsorbed amount of silver ion was examined by the variation of concentration of silver nitrate, temperature, pressure and curing time. Optimum condition for silver-hydroxyapatite adsorption could be achieved. Physical and chemical characteristic properties of synthesized silver-hydroxyapatite were tested by ICP-MS, SEM-EDAX, DSC and XRD. Antibiotic properties for gram positive staphylococcus aureus (ATCC 6538) and gram negative escherichia coli (ATCC 25922) were tested by shake flake method.
A Study on the Bond Strength of BCB-bonded Wafers
Kwon, Yong-Chai ; Seok, Jong-Won ; Lu, Jian-Qiang ; Cale, Timothy ; Gutmann, Ronald ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 479~486
Four point bending is used to study the dependences of bond strength of benzocyclobutene(BCB) bonded wafers and BCB thickness, the use of an adhesion promoter, and the materials being bonded. The bond strength depends linearly on BCB thickness, due to the thickness-dependent contribution of the plastic dissipation energy of the BCB and thickness independence of BCB yield strength. The bond strength increases by about a factor of two with an adhesion promoter for both 2.6 μm and 0.4 μm thick BCB, because of the formation of covalent bonds between adhesion promoter and the surface of the bonded materials. The bond strength at the interface between a silicon wafer with deposited oxide and BCB is about a factor of three higher than that at the interface between a glass wafer and BCB. This difference in bond strength is attributed to the difference in Si-O bond density at the interfaces. At the interfaces between plasma enhanced chemical vapor deposited (PECVD) oxide coated silicon wafers and BCB, and between thermally grown oxide on silicon wafers and BCB, 12~13 and 15~16 bonds/nm2 need to be broken. This corresponds to the observed bond energies, G0s, of 18 and 22 J/m2, respectively. Maximum 7~8 Si-O bonds/nm2 are needed to explain the 5 J/m2 at the interfaces between glass wafers and BCB.
Molecular Separation of Dibromobenzene Isomers by using Selective Guest Inclusion of
Kim, Jin-Soo ; Park, Ji-Min ; Yi, Jong-Heop ; Kim, Woo-Sik ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 487~492
Using the selective host-guest inclusion of G2[naphthalene disulfonate], the structural isomers of 1,2-dibromobenzene and 1,3-dibromobenzene were separated. As such, 1,3-dibromobenzene was selectively included as guest into the host framework in mixture isomers over 30% fraction of 1,3- dibromobenzene (X1,3-DBB=0.3) whereas 1,2-dibromobenzene as guest was selective to the inclusion below X1,3-DBB=0.3. This was due to the selectivity of host framework toward the guest molecules playing a role of template to the host framework. From the powder pattern XRD of inclusion compounds crystallized in pure isomer and mixture solutions, the template roles of guest molecules to the host framework were confirmed. Using the DSC, it was found that the more energy was required to release 1,3-dibromobenzene of guest from the host framework than 1,2-dibromobenzene due to the higher thermal stability. The thermal stability of the G2NDS-1,3-dibromobenzene inclusion compound was consistent with the high selectivity of 1,3- dibromobenzene to the host framework in broad range of fraction in the isomer mixture
Fabrication of Non Viral Vector for Drug and Gene Delivery using Particle Replication In Non-Wetting Templates (PRINT) Technique
Park, Ji-Young ; Gratton, Stephanie ; Benjamin, Maynor ; Lim, Jomg-Sung ; Desimone, Joseph ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 493~499
Polymeric hydrogel particles were fabricated to demonstrate the scale-up possibilities with the Particle Replication In Non-wetting Templates (PRINT) process. A permanently etched, specifically designed master was made on a silicon wafer using conventional photolithography, then reactive ion etching. The master and substrate were used repeatedly to make a large number of identical elastomeric perfluoropolyethers (PFPE) replica molds. The PFPE replica molds were used to fabricate and harvest individual, monodisperse micron-sized particles using the PRINT process. A water-soluble polymer adhesive was used as a sacrificial layer for harvesting particles. Particles were composed of biodegradable poly (ethylene glycol) diacrylate (PEG-diA), and aminoethylacrylate (AEM) and 2-acryloxyethyltrimethyl ammonium chloride (AETMAC) were added to them for improving the uptake of the cells. This study suggested PRINT used to produce the uniformed and shape specific biodegradable polymer is the effective technique for the non viral vector for the drug and the gene delivery.
Effect of Membrane Materials on Membrane Fouling and Membrane Washing
Shim, Hyun-Sool ; Jung, Chul-Woo ; Son, Hee-Jong ; Sohn, In-Shik ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 500~505
The objectives of this research were to (1) identify the membrane fouling potential due to different fractions of NOM (2) correlate the physicochemical properties of NOM and membranes with the adsorption of humic substances on membrane (4) find out the effect of membrane physical and chemical washing according to membrane material. The static adsorption test and adsorption test showed that hydrophobic organics adsorbed much more quickly than hydrophilic organics. In case of the effect of membrane properties on the adsorption of organic fractions, the adsorption rate ratio(a) of hydrophobic membrane (0.016, 0.077) was greater than that of hydrophilic membrane (0.010, 0.033) regardless of the kind of organic fractions. This suggests that the UF membrane fouling were occurred mainly by internal pore size decreasing due to adsorption of organic into pore surface for hydrophobic membrane, and by sieving of organics and forming a gel layer on the membrane surface for hydrophilic membrane. In conclusion, the decrease in the pore volume, which was caused by the organic adsorption into the internal pore, was greater with the hydrophobic membrane than with the hydrophilic membrane. In case of the effect of membrane properties on permeate flux, the rate of flux decline for the hydrophobic membrane was significantly greater than that for the hydrophilic membrane.
Selection of the Best Oxygen Carrier Particle for Syngas Fueled Chemical-Looping Combustor
Ryu, Ho-Jung ; Kim, Ji-Woong ; Jo, Wan-Kuen ; Park, Moon-Hee ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 506~514
To select the best oxygen carrier particle for syngas fueled chemical-looping combustor, the reduction reactivity and carbon deposition characteristics were determined in a thermogravimetric analyzer. Four kinds of oxygen carrier particles (NiO/bentonite, NiO/LaAl11O18, CoxOy /CoAl2O4, NiO/NiAl2O4) were tested with the simulated syngas (30% H2, 10% CO2, 60% CO) as a reduction gas. With each of these particles, the maximum conversion and oxygen transfer capacity increase with increasing the reduction temperature At the given experimental range, the optimum operating temperature to maximize oxygen transfer rate is found to be 900 ℃ and carbon deposition on the particles could avoid at the temperature above 800 ℃. Among four kinds of oxygen carrier particles, the NiO-based particles exhibits better reactivity than the CoO-based particle. Moreover, the NiO/bentonite particle produces the best reactivity based on the oxygen transfer rate and the degree of carbon deposition. The measured oxygen transfer rate increases as the metal oxide content in NiO/bentonite particle is increased thereby higher metal oxide contents could provide stable operation of chemical-looping combustor.
A Simulation Study on the Analysis of Optimal Gas Storage System of the Depleted Gas Reservoir
Lee, Young-Soo ; Choi, Hae-Won ; Lee, Jeong-Hwan ; Han, Jeong-Min ; Ryou, Sang-Soo ; Roh, Jeong-Yong ; Sung, Won-Mo ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 515~522
this study we have attempted to evaluate the technical feasibility of 『BB-HY』, which is depleted gas reservoir as a gas storage field, using the commercial compositional simulator『ECLIPSE 300』. The『BB-HY』 reservoir has an initial gas in place of 143 BCF which is relatively small, and its porosity and permeability are 19.5% and 50 md, respectively. For 『BB-HY』 gas reservoir, we have performed a feasibility analysis by investigating the cushion gas (or working gas), converting time to gas storage field, operation cycle, number of wells and the possible application of horizontal borehole as well. From the simulation results, it was found that the amount of cushion gas in 『BB-HY』reservoir is required at least 50% of IGIP in order to operate stably as gas storage field. When one produces gas for longer time and hence the remaining gas in reservoir is less than optimal cushion gas, no technical problem was occurred as long as additional cushion gas is injected up to the optimal cushion gas. In the case of changing the operation cycle into producing gas for three months during winter season from producing five months, the result shows that either the cushion gas should be greater than 60% or the more number of wells should be drilled. Meanwhile, from the results of sensitivity analysis for the number of wells, in cases of operating six or eight vertical wells, the stable reproduction of the injected gas can not be possible in 『BB-HY』gas reservoir since the remaining gas in reservoir is increased. Therefore, in 『BB-HY』 reservoir, at least ten vertical wells should be drilled for the stable operation of gas. This time, when three horizontal wells are additionally drilled including the existing two vertical wells, it was found that the operation of injection and reproduction of gas is relatively stable in『BB-HY』gas reservoir.
Effect of Metal Salt Coagulant on Membrane Fouling During Coagulation-UF Membrane Process
Jung, Chul-Woo ; Shim, Hyun-Sool ; Sohn, In-Shik ;
Korean Chemical Engineering Research, volume 45, issue 5, 2007, Pages 523~528
The objectives of this research are to investigate the mechanism of coagulation affecting UF, find out the effect of metal salt coagulant on membrane fouling. Either rapid mixing + UF or slow mixing + UF process caused much less flux decline. For PACl coagulant, the rate of flux decline was reduced for both hydrophilic and hydrophobic membrane than alum due to higher formation of flocs. In addition, the rate of flux decline for the hydrophobic membrane was significantly greater than for the hydrophilic membrane, regardless of pretreatment conditions. In general, Coagulation pretreatment significantly reduced the fouling of the hydrophilic membrane, but did little decrease the flux reduction of the hydrophobic membrane. When an Al(III) salt is added to water, monomers, polymers, or solid precipitates may form. Different Al(III) coagulants (alum and PACl) show to have different Al species distribution over a rapid mixing condition. During the rapid mixing period, for alum, formation of dissolved Al(III) (monomer and polymer) increases, but for PACl, precipitates of Al(OH)3(s) increases rapidly. This experimental results pointed out that precipitates of Al(OH)3(s) rather than dissolved Al(III) formation is major factor affecting flux decline for the membrane.