Korean Journal of Chemical Engineering (v.33, #3)
Environmental plasma-catalysis for the energy-efficient treatment of volatile organic compounds by Quang Hung Trinh; Young Sun Mok (735-748).
Nonthermal plasma (NTP) coupled with catalysis is a promising technique for the abatement of dilute volatile organic compounds (VOCs), because it is operable under mild reaction conditions, i.e., low temperature and atmospheric pressure. This review addresses the mechanistic aspects of catalyst activation by NTP, such as the generation and fixation of reactive species, facilitation of redox cycles, photocatalysis, and local heating, to clarify the combined effects of plasma and catalysis. The plasma-catalytic removal of VOCs preferentially requires the catalyst to have a large specific surface area, high surface oxygen storage capacity, and to be highly reducible. The energy consumption and deactivation of catalysts are considered by comparing continuous and cyclic operations in terms of specific input energy, VOC removal and energy efficiencies, and byproduct formation. Based on the information in the literature, a plasma-catalytic system operating in cyclic adsorption-oxidation mode is recommended for the treatment of air contaminated by dilute VOCs. Finally, the effects of NTP on the regeneration of deactivated catalysts are also discussed.
Keywords: VOCs; Nonthermal Plasma; Catalyst; Plasma-catalysis; Cyclic Treatment; Mechanisms
Ultrasonic preparation of mesoporous silica using pyridinium ionic liquid by Ana-Maria Putz; Adél Len; Catalin Ianăşi; Cecilia Savii; László Almásy (749-754).
Mesoporous silica matrices have been prepared via classic acid catalyzed and sono-catalyzed sol-gel routes. Tetramethoxysilan (TMOS) and methyl-trimethoxysilane (MTMS) were used as silica precursors, and N-butyl-3-methylpyridinium tetrafluoroborate ([bmPy][BF4]) was employed as co-solvent and pore template. The ionic liquid (IL) to silica mole ratio was varied between 0.007 and 0.07. Nitrogen adsorption-desorption and small-angle neutron scattering measurements were used to characterize the obtained materials. The ionic liquid played the role of catalyst that affected the formation of the primary xerogel particles, and changed the porosity of the materials. Ultrasound treatment resulted in microstructure change on the level of the colloid particle aggregates. In comparison with IL containing xerogels, the IL containing sonogels show increased pore diameter, bigger pore volumes and diminished surface areas.
Keywords: Ionic Liquid; Ultrasound; SANS; TMOS (Tetramethoxysilane); MTMS (Trimethoxymethylsilane)
Development of an optimal multifloor layout model for the generic liquefied natural gas liquefaction process by Jin-Kuk Ha; Euy Soo Lee (755-763).
Liquefied natural gas (LNG) is attracting significant interest as a clean energy alternative to other fossil fuels, mainly for its ease of transport and low carbon dioxide emission. As worldwide demand for LNG consumption has increased, liquefied natural gas floating, production, storage, and offloading (LNG-FPSO) operations have been studied for offshore applications. In particular, the LNG-FPSO topside process systems are located in limited areas. Therefore, the process plant layout of the LNG-FPSO topside systems will be optimized to reduce the area cost occupied by the topside equipment, and this process plant layout will be designed as a multifloor concept. We describe an optimal layout for a generic offshore LNG liquefaction process operated by the dual mixed refrigerant (DMR) cycle. To optimize the multifloor layout for the DMR liquefaction cycle process, an optimization was performed by dividing it into first and the second cycles. A mathematical model of the multifloor layout problem based on these two cycles was formulated, and an optimal multifloor layout was determined by mixed integer linear programming. The mathematical model of the first cycle consists of 725 continuous variables, 198 equality constraints, and 1,107 inequality constraints. The mathematical model of the second cycle consists of 1,291 continuous variables, 286 equality constraints, and 2,327 inequality constraints. The minimization of the total layout cost was defined as an objective function. The proposed model was applied to DMR liquefaction cycle process to determine the optimal multifloor layout.
Keywords: Process Plant Layout; MILP; Optimization; Dual Mixed Refrigerant Cycle
Case study of surge avoidance design for centrifugal compressor systems during emergency shut-down (ESD) by Se-jin Pak; Ju Woung Yoon; Seojin Kim; Felicia Salim; Jaihyo Lee; In-Won Kim (764-774).
Compression systems with centrifugal compressors are widely used in gas involving processes. Surge protection system design is crucial in avoiding any damage in abnormal circumstances such as emergency shutdown (ESD), start-up, coast-down operation, and normal shutdown. We analyzed four cases of existing centrifugal compressor systems, three CO2 compression systems and one off-gas compression system, to study the surge protection availability during ESD. All compression systems were working well at normal operating condition, but some systems could not avoid surge during ESD. To check the surge cases, the surge criteria flowchart was suggested and surge analysis through dynamic simulation was done using a commercial process simulator. To avoid a surge during ESD, a sensitivity analysis was done while considering the following process parameters: pre-stroke time, anti-surge valve (ASV) type, capacity, and stroke time. We optimized ASV design using response surface method with two selected parameters from the sensitivity study, ASV capacity and stroke time. Finally, the installation of the hot gas recycle system was analyzed to avoid surge occurrence.
Keywords: Compression System; Compressor Surge; Emergency Shutdown (ESD); Surge Protection; Dynamic Simulation
New criteria for filament breakup in droplet-on-demand inkjet printing using volume of fluid (VOF) method by Sadegh Poozesh; Nelson Akafuah; Kozo Saito (775-781).
A volume of fluid (VOF) numerical study is presented in which new pi number-based criteria are discussed that identify and separate three different regimes for a droplet-on-demand (DOD) print-head system. A trailing filament coalesces into the main droplet while the filament breaks into one or multiple satellite droplet(s). The numerical simulation results are compared with published large-scale experimental results that used a 2 mm diameter inkjet nozzle head, roughly 50 times larger than the actual diameter of inkjet outlets. Liquid filament break-up behavior is predicted using a combination of two pi-numbers, including either Weber (We)-Ohnesorge (Oh) number couplets or Reynolds (Re)-Weber (We) number couplets that are dependent only on the ejected liquid properties and the velocity waveform at the print-head inlet. These new criteria have merit over the currently existing ones that require accurate measurements of actual droplets to determine filament physical features like length and diameter .
Keywords: Inkjet Printing; Droplet on Demand; Scale Modelling; Volume of Fluid (VOF); Filament Breakup
A numerical study on the performance evaluation of ventilation systems for indoor radon reduction by Ji Eun Lee; Hoon Chae Park; Hang Seok Choi; Seung Yeon Cho; Tae Young Jeong; Sung Cheoul Roh (782-794).
Numerical simulations were conducted using computational fluid dynamics to evaluate the effect of ventilation conditions on radon (222Rn) reduction performance in a residential building. The results indicate that at the same ventilation rate, a mechanical ventilation system is more effective in reducing indoor radon than a natural ventilation system. For the same ventilation type, the indoor radon concentration decreases as the ventilation rate increases. When the air change per hour (ACH) was 1, the indoor radon concentration was maintained at less than 100 Bq/m3. However, when the ACH was lowered to 0.01, the average indoor radon concentration in several rooms exceeded 148 Bq/m3. The angle of the inflow air was found to affect the indoor air stream and consequently the distribution of the radon concentration. Even when the ACH was 1, the radon concentrations of some areas were higher than 100 Bq/m3 for inflow air angles of 5° and 175°.
Keywords: Computational Fluid Dynamics; Exhalation; Indoor Air; Radon; Ventilation
Effects of uniform magnetic field on the interaction of side-by-side rising bubbles in a viscous liquid by Amin Hadidi; Davood Jalali-Vahid (795-805).
Effects of uniform magnetic fields on the interaction and coalescence of side-by-side rising bubbles of dielectric fluids were not studied; so in the present research, effects of different strengths of uniform magnetic field on the interaction of two bubbles rising side by side in a viscous and initially stagnant liquid are studied, numerically. For numerical modeling of the problem, a full computer code was developed to solve the governing equations which are continuity, Navier-Stokes, magnetic field and interface capturing equations which are level set and re-initialization equations. The finite volume method is used for the discretization of the hydrodynamic equations where the finite difference method is used to discretization of the magnetic field equations. The results are compared with available numerical and experimental results which show a good agreement. It is found that the uniform magnetic field can be used for contactless control of side-by-side coalescence of bubbles.
Keywords: Uniform Magnetic Field; Coalescence; Bubble Pairs; Two-phase Flow; Side-by-side Rising Bubbles
Dehydration of d-xylose over SiO2-Al2O3 catalyst: Perspective on the pathways for condensed products by Su Jin You; Eun Duck Park; Myung-June Park (806-811).
This work addresses the kinetic mechanism for the dehydration of D-xylose over the SiO2-Al2O3 solid catalyst, where the formation of condensed products is included in addition to the production of furfural and its decomposition. The kinetic modeling and parametric sensitivity show that the isomerization of D-xylose takes place in the early stages of the reaction, followed by the dehydration of isomers. Accordingly, the homogeneous polymerization of isomers is found to be dominant. The developed model is used to evaluate the effects of operating conditions on the catalytic performance; high temperature and D-xylose concentration guarantee high furfural yield.
Keywords: D-Xylose; Furfural; Dehydration; Silica-alumina; Kinetic Modeling
Application of Ni-doped ZnO rods for the degradation of an azo dye from aqueous solutions by Mitra Gholami; Mehdi Shirzad-Siboni; Jae-Kyu Yang (812-822).
Ni-doped ZnO rods were applied as a photocatalyst for the degradation of an azo dye (Reactive Black 5). Effects of solution pH, catalyst dosage, initial RB5 concentration, H2O2 concentration, different purging gases, and type of organic compounds on the removal efficiency of RB5 were studied. Ni-doped ZnO rods were synthesized by co-precipitation method. Neutral pH was selected as an optimal pH condition due to a photo-corrosion of ZnO in acidic and basic conditions. Photocatalytic degradation efficiency of RB5 was increased as the catalyst dosage increased up to 1 g/L, while it was decreased by increasing initial RB5 concentration. Pseudo-first-order rate constant (k obs ) decreased from 0.122 to 0.0051 min-1 and electrical energy per order (E Eo ) increased from 39.34 to 941.18 (kWh/m3) by increasing RB5 concentration from 5 to 100mg/L, respectively. Photocatalytic degradation efficiency of RB5 increased by increasing H2O2 concentration, but this trend was not observed above 10 mM. Photocatalytic degradation efficiency of RB5 increased in the presence of folic acid and citric acid while interference was observed in the presence of humic acid, EDTA, oxalic acid, and phenol. Photocatalytic activity was maintained even after five successive cycles.
Keywords: Synthesis; Ni-doped ZnO Rods; Reactive Black 5; Catalyst; Kinetic Models
Influence of phosphorous addition on Bi3Mo2Fe1 oxide catalysts for the oxidative dehydrogenation of 1-butene by Jung-Hyun Park; Chae-Ho Shin (823-830).
Bi3Mo2Fe1P x oxide catalysts were prepared by a co-precipitation method and the influence of phosphorous content on the catalytic performance in the oxidative dehydrogenation of 1-butene was investigated. The addition of phosphorous up to 0.4mole ratio to Bi3Mo2Fe1 oxide catalyst led to an increase in the catalytic performance; however, a higher phosphorous content (above P=0.4) led to a decrease of conversion. Of the tested catalysts, Bi3Mo2Fe1P0.4 oxide catalyst exhibited the highest catalytic performance. Characterization results showed that the catalytic performance was related to the quantity of a π-allylic intermediate, facile desorption behavior of adsorbed intermediates and ability for re-oxidation of catalysts.
Keywords: Butadiene; Oxidative Dehydrogenation; Bi3Mo2Fe1P x Oxide Catalyst; 1-C4H8-temperature-programmed Desorption; Temperature-programmed Re-oxidation
Conversion of methanol into light olefins over ZSM-11 catalyst in a circulating fluidized-bed unit by Xiaojing Meng; Huiwen Huang; Qiang Zhang; Minxiu Zhang; Chunyi Li; Qiukai Cui (831-837).
Methanol conversion and the reaction pathway were investigated in a pilot-scale circulating fluidized-bed (CFB) unit over hierarchical ZSM-11 catalyst. Experimental results indicated that ZSM-11 catalyst was highly resistant to external coke due to the formation of mesopores. Elevated temperatures favored the production of propylene and butylene and decreased the yield of ethylene. Additionally, no direct relations were shown between the formation of ethylene and other products under different pressures, suggesting that ethylene was a primary product produced at the initial of the reaction. Methylation-cracking and oligomerization were verified as the main reaction pathway for the formation of C 3 + alkenes., Methylation and oligomerization of olefins were dominated under high methanol partial pressure and consequently responsible for the production of higher olefins, while the b-scission of C 7 = for propene and butylene, and C 8 = for butylene were enhanced at low methanol partial pressure.
Keywords: ZSM-11 Catalyst; Methanol Conversion; Reaction Pathway; CFB Unit; Reaction Conditions
Selective oxidation of H2S to sulfur over CeO2-TiO2 catalyst by Dong-Heon Kang; Moon-Il Kim; Dae-Won Park (838-843).
The catalytic oxidation of hydrogen sulfide (H2S) to elemental sulfur was studied over CeO2-TiO2 catalysts. The synthesized catalysts were characterized by various techniques such as X-ray diffraction, BET, X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of ammonia, and scanning electron microscopy (SEM). Catalytic performance studies of the CeO2-TiO2 catalysts showed that H2S was successfully converted to elemental sulfur without considerable emission of sulfur dioxide. CeO2-TiO2 catalysts with Ce/Ti=1/5 and 1/3 exhibited the highest H2S conversion, possibly due to the uniform dispersion of metal oxides, high surface area, and high amount of acid sites.
Keywords: Selective Oxidation; Hydrogen Sulfide; Sulfur; CeO2-TiO2 Catalyst
Process conditions for complete decomposition of CHF3 in a dielectric barrier discharge reactor by Duc Ba Nguyen; Won Gyu Lee (844-850).
Plasma decomposition of CHF3 was investigated using a dielectric barrier discharge immersed in an electrically insulating oil bath in a mixture of CHF3, O2, and N2. CHF3 was well decomposed under a relatively high applied voltage in an atmospheric pressure plasma system. The main by-product was CO2 and its selectivity increased with a decrease in the CHF3 concentration in the feed. Complete decomposition of CHF3 was achieved at a typical process range: an applied voltage ≥7.0 kVp, an initial CHF3 flow rate of 3ml/min, and a total flow rate of 500ml/min. The value of energy efficiency and energy density at the center range for the complete decomposition of CHF3 was 0.01 mmol/kJ and 6.00kWh/Nm3, respectively.
Keywords: CHF3 ; Dielectric Barrier Discharge; Plasma; Decomposition of CHF3 ; Electrically Insulating Oil
Fuel characteristics of agropellets fabricated with rice straw and husk by In Yang; Seong-ho Kim; Moon Sagong; Gyu-Seong Han (851-857).
Our aim was to identify the potential of rice straw (RS) and rice husk (RH) as raw materials for pellet production. Compared to woody biomass, RS and RH can be easily dried, but contain significant levels of ash. Higher heating values of oven-dried RS and RH are slightly lower than those of commercial wood pellets. RS and RH contain substantially more silicon, potassium and calcium than larch sawdust. However, ash and moisture contents of RS was significantly reduced following a 15-week exposure period on rice paddy. These results suggest that RS and RH present suitable alternatives to wood as raw materials for pellet production due to their availability, relatively high calorific value and low moisture content. The durability of RS and RH pellets improved steadily with increasing pelletizing temperature and time. Pelletization under appropriate conditions also enabled the durability and bulk density of RS and RH to be improved, enhancing their potential as alternative combustion fuels.
Keywords: Rice Straw; Rice Husk; Pellet; Ash Content; Outdoor Exposure
Organic di-radical rechargeable battery with an ionic liquid-based gel polymer electrolyte by Kyoungho Kim; Jae-Kwang Kim (858-861).
We employed 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMImTFSI)-based gel polymer electrolyte (ILPE) of low viscosity to prevent the instability of the di-TEMPO organic (DTO) electrode with enhancement of the cycle ability and rate-capability. The gel polymer electrolyte was prepared by electrospinning process. The DTO//ILPE//Li cell showed high initial capacity of 80mAh g-1 for 1 C and 68mAh g-1 for 10 C-rate, which corresponds to 100 and 85% of theoretical capacity, respectively. The cycle ability and rate-capability were much improved by using of EMImTFSI-based gel polymer electrolyte without self-discharge.
Keywords: EMImTFSI; Di-TEMPO Electrode; Cycle Ability; Rate-capability; Organic Batteries
Evaluation of the susceptibility of coal to spontaneous combustion by a TG profile subtraction method by Yulong Zhang; Junfeng Wang; Sheng Xue; Yue Wu; Zhengfeng Li; Liping Chang (862-872).
It is imperative to have an in-depth understanding of the intrinsic reaction between coal and oxygen during low-temperature oxidation, as the reaction is the main source responsible for the self-heating and spontaneous combustion of coal. As low-temperature oxidation of coal involves a series of physical and chemical process and many parallel reactions, it is difficult to directly investigate the intrinsic reaction between coal and oxygen by conventional analytical method. Thermogravimetric analysis (TGA) was used to investigate the intrinsic reaction between coal and oxygen based on the mass change. By means of the subtraction analysis method of TGA, the TG-subtraction curves were obtained by subtracting the TG-N2 curves from the TG-air curves. The results indicate that a TG-subtraction curve can better reflect the intrinsic reaction of coal oxidation than a TG-air curve by eliminating the influence of evaporation of water and thermal decomposition of inherent oxygen-containing groups. In terms of the rate of mass increase, the intrinsic reactions can be divided into three stages: slow oxidation stage, advanced oxidation stage and rapid oxidation stage. The activation energy at each of the stages, obtained by Coats and Redfern’s model, can be used to as a technical parameter to evaluate the proneness of coal spontaneous combustion. The optimum experiment conditions were also developed to study low-temperature coal oxidation with the subtraction method of TGA.
Keywords: TGA; Coal; Low-temperature Oxidation; Subtraction Method; Kinetics
Pretreatment of sweet sorghum bagasse by alkaline hydrogen peroxide for enhancing ethanol production by Weixing Cao; Chen Sun; Jiangping Qiu; Xudong Li; Ronghou Liu; Le Zhang (873-879).
Effects of severe and mild alkaline hydrogen peroxide (AHP) pretreatment on ethanol production from sweet sorghum bagasse via pre-simultaneous saccharification fermentation, and the chemical structure changes of the substrates were investigated. The results showed that the bagasse pretreated by severe AHP could produce more ethanol than that of mild AHP. The maximum ethanol concentration of the bagasses from mild and severe AHP pretreatment with 8% bagasse loading was 7.642±0.140 g/L and 19.330±0.085 g/L, respectively. Moreover, the FTIR and NMR analysis illustrated that the molecule and surface structures of the pretreated bagasse were significantly changed compared with the control. The potential biomass energy production of the effluent from the pretreatment was also briefly discussed for future utilization of waste solution.The heat energy potentials of waste solution with severe and mild AHP pretreatment were 367.2 kJ/L effluent and 327.6 kJ/L effluent , respectively.
Keywords: Sweet Sorghum Bagasse; Alkaline Hydrogen Peroxide Pretreatment; Ethanol Fermentation; Energy Potential; Biofuel
Semi-transparent thin film solar cells by a solution process by Van Ben Chu; Se Jin Park; Gi Soon Park; Hyo Sang Jeon; Yun Jeong Hwang; Byoung Koun Min (880-884).
Easily processed, low cost, and highly efficient solar cells are desirable for photovoltaic conversion of solar energy to electricity. We present the fabrication of precursor solution processed CuInGaS2 (CIGS) thin film solar cells on transparent indium tin oxide (ITO) substrates. The CIGS absorber film was prepared by a spin-coating method, followed by two successive heat treatment processes. The first annealing process was on a hot plate at 300 °C for 30 min in air to remove carbon impurities in the film; this was followed by a sulfurization process at 500 °C in an H2S(1%)/Ar environment to form a polycrystalline CIGS film. The absorber film with an optical band-gap of 1.52 eV and a thickness of about 1.1 µm was successfully synthesized. Because of the usage of a transparent glass substrate, a bifacial CIGS thin film device could be achieved; its power conversion efficiency was measured to be 6.64% and 0.96% for front and rear illumination, respectively, under standard irradiation conditions.
Keywords: Solar Cell; CIGS; ITO; Precursor Solution; Thin Film
Stabilization of hydrogen peroxide using tartaric acids in Fenton and Fenton-like oxidation by Hyung Suk Oh; Jeong-Jin Kim; Young-Hun Kim (885-892).
The stabilization of hydrogen peroxide is a key factor in the efficiency of a Fenton reaction. The stability of hydrogen peroxide was evaluated in a Fenton reaction and Fenton-like reactions in the presence of tartaric acid as a stabilizer. The interactions between ferrous or ferric iron and tartaric acid were observed through spectroscopic monitoring at variable pH around pKa1 and pKa2 of the stabilizer. Ferric iron had a strong interaction with the stabilizer, and the strong interaction was dominant above pKa2. At a low pH, below pKa1, the stabilizing effect was at its maximum and the prolonged life-time of hydrogen peroxide gave a higher efficiency to the oxidative degradation of nitrobenzene. In Fenton-like reactions with hematite, the acidic conditions caused dissolution of iron from an iron oxide, and an increase in iron species was the result. Tartaric acid showed a stabilizing effect on hydrogen peroxide in the Fentonlike system. The stabilization by tartaric acid might be due to an inhibition of catalytic activity of dissolved iron, and the stabilization strongly depends on the ionization state of the stabilizer.
Keywords: Fenton Oxidation; Fenton-like Reactions; Stabilization; Hydrogen Peroxide; Life-time; Tartaric Acid
Removal of ciprofloxacin from aqueous solution by a continuous flow electro-coagulation process by Jalal Basiri Parsa; Taher Mehdi Panah; Farideh Nabizadeh Chianeh (893-901).
This study deals with the performance and modeling of the electro-coagulation process for ciprofloxacin (CIP) removal by using aluminum electrode as anode in a continuous electrochemical reactor. The initial pH, temperature, current density, time and flow rate were selected as independent variables in response surface methodology (RSM) involving a five-level central composite design (CCD), while CIP removal efficiency was considered as the response function. The result of optimization showed that the maximum amount of CIP removal efficiency (88%) presented at the optimal condition of pH=5.6, t=100min, T=25.5 °C, I=5.6mA/cm2 and V=25.9 mL/min. In addition, the mineralization of the CIP was investigated by chemical oxygen demand (COD) and total organic carbon (TOC) measurements that showed 77% COD removal and 49%TOC removal.
Keywords: Electro-coagulation; Ciprofloxacin; Response Surface Methodology; Continuous Flow Process
Synthesis of nanostructured adsorbent and dye adsorption modeling by an intelligent model for multicomponent systems by Niyaz Mohammad Mahmoodi; Zahra Hosseinabadi-Farahani; Hooman Chamani (902-913).
β-Ni(OH)2 nanoparticle was synthesized and used as an adsorbent. The prepared adsorbent was characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). Least square support vector machine (LSSVM) as an intelligent model was applied for modeling of dye removal based on experimental data obtained from laboratory. The nanostructured adsorbent was used to remove three cationic dyes (BB41: Basic blue 41, BR18: Basic Red 18 and BR46: Basic Red 46) from single and binary systems at room temperature. The kinetics and isotherm of dye adsorption was studied. The effects of adsorbent dosage and initial dye concentration were elucidated. The kinetic studies showed that the adsorption data followed pseudo-second order kinetics model. The isotherm analysis indicates that the adsorption data can be represented by Langmuir in single systems. Based on graphical plots and the values of statistical parameter, LSSVM as an intelligent model is suitable for modeling of dye adsorption from single and binary systems.
Keywords: Nanostructured Adsorbent; Synthesis; Intelligent Modeling; Binary System; Dye Adsorption; Wastewater
Immobilization technologies for the management of hazardous industrial waste using granite waste (case study) by Mohamed R. Lasheen; Azza M. Ashmawy; Hanan S. Ibrahim; Shimaa M. Abdel Moniem (914-921).
Full characterization of granite waste sludge (GWS) was accomplished by X-ray diffraction (XRD) and Xray fluorescence (XRF) for identification of its phase and chemical composition. Different leaching tests were conducted to determine the efficiency of the GWS for metal stabilization in hazardous sludge. The leaching of the metals from stabilized contaminated sludge was decreased as the GWS amount increased. Only 15% of GWS was sufficient for stabilization of all metal ions under investigation. The main reason for metal immobilization was attributed to the aluminosilicates or silicates matrix within the GWS, which can transform the metals in the form of their insoluble hydroxides or absorbed in the stabilized matrix. Also, solidification/stabilization technique was used for remediation of contaminated sludge. Compressive strength test after curing for 28 days was used for measuring the effectiveness of remediation technique; it was found to be 1. 88MPa. This indicated that the remediated sludge was well solidified and safe to be used as a raw substance for roadway blocks. Therefore, this huge amount of by-product sludge derived from the granite cutting industry, which has a negative environmental impact due to its disposal, can be utilized as a binder material for solidification/stabilization of hazardous sludge.
Keywords: Compressive Strength; Leachability; Solidification; Stabilization; Granite Waste Sludge
Process modeling and optimization of Rhodamine B dye ozonation in a novel microreactor equipped with high frequency ultrasound wave by Mahboubeh Faryadi; Masoud Rahimi; Mona Akbari (922-933).
This paper reports the effect of 1.7 MHz ultrasound wave on decolorization efficiency of Rhodamine B (RB) solution by ozone in a T-type microreactor. Response surface methodology using central composite design (CCD) was used for analysis and optimization of the reaction conditions. The effective parameters such as solution pH, dye initial concentration, liquid volumetric flow rate, ozone dosage and the length of microreactor on decolorization process were investigated. Rhodamine B removal from solution was determined in presence of and without sonication. The results indicate that for both modes, the decolorization efficiency of RB increased with increase of the ozone dosage as well as the length of employed microreactor. However, with increase of RB initial concentration and liquid flow rate, the decolorization efficiency was decreased. The comparison between the reactors with and without sonication shows that the application of ultrasound wave is effective more than 15% on removal efficiency of RB at various conditions. At optimum conditions, the experimental RB removal yield of 97. 3% and 95. 8 was obtained for with and without irradiation layouts, respectively. The statistical analyses and the agreement of the experimental results with model predictions showed the reliability of the regression model.
Keywords: Decolorization; Microreactor; Ooptimization; Ozonation; Rhodamine B
Size-controlled synthesis of chalcogen and chalcogenide nanoparticles using protic ionic liquids with imidazolium cation by Boominathan Meenatchi; Velayutham Renuga; Ayyar Manikandan (934-944).
Green synthesis of selenium (chalcogen) nanoparticles (SeNPs) has been successfully attained by simple wet chemical method that involves the reaction of six different protic ionic liquids with imidazolium cations and sodium hydrogen selenide (NaHSe) in the presence of poly ethylene glycol-600 (PEG-600) as an additional stabilizer. The obtained SeNPs were characterized using UV spectral (UV), Fourier transform infra-red (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscope (SEM) with energy dispersive X-ray (EDX) and high resolution transmission electron microscope (TEM) analysis. The results illustrate that the synthesized SeNPs are spherical in shape with size ranging 19-24 nm and possess good optical property with greater band gap energy, high thermal stability up to 330 °C, low melting point of 218-220 °C comparing to precursor selenium. Using the synthesized SeNPs, two chalcogenides such as ZnSe and CdSe semiconductor nanoparticles were synthesized and characterized using XRD, SEM with EDX and TEM analysis. The fabricated CdSe and ZnSe nanoparticles appeared like pebble and cluster structure with particle size of 29.97 nm and 22.73 nm respectively.
Keywords: Protic Ionic Liquids; Selenium Nanoparticles; Semiconductor; Chalcogenides; Optical Property
Adsorptive characteristics of the polyurethane-immobilized Corynebacterium glutamicum biosorbent for removal of Reactive Yellow 2 from aqueous solution by Sung Wook Won; Juan Mao; Gopinathan Sankar; Hyun-Cheol Lee; Yeoung-Sang Yun (945-951).
Polyurethane (PU) was evaluated for its possibility as an immobilization matrix for the raw biomass of Corynebacterium glutamicum. Initially, different blending ratios of the raw biomass to PU weight were tested, and the ratio of 7: 3 was identified as the optimal condition. PU-immobilized biosorbent (PUIB) with a particle size ranging from 0.425 to 0.18mm was selected for the adsorption of Reactive Yellow 2 (RY2). The uptake of RY2 on the PUIB was favorable at acidic pH, especially below 3. According to the Langmuir model, the maximum RY2 uptakes were estimated to be 104.0, 93.3, and 87.3mg/g at pH 2, 3, and 4, respectively. The pseudo-first-order and pseudo-secondorder models were applied to fit the biosorption kinetic data; the latter model fitted the data well with a high coefficient of determination (R2) and low average percentage error (ε) values. The RY2-sorbed PUIB was able to be regenerated and reused for five cycles of the adsorption and desorption processes.
Keywords: Polyurethane; Corynebacterium glutamicum ; Reactive Dye; Immobilization; Regeneration
The antimicrobial activity of as-prepared silver-loaded phosphate glasses and zirconium phosphate by Wang Jing; Ji Zhi Jiang; Shui Zhong He; Yang Yang; Zhao Chun Yan; Wang Xiao Yan (952-957).
The antimicrobial activities of silver-loaded zirconium phosphate (JDG) and silver-loaded phosphate glasses (ZZB) against Escherichia coli were studied. Although the silver content in JDG was higher than that in ZZB, ZZB suspensions showed better antimicrobial property than JDG suspensions, especially at low concentrations. The antimicrobial activity was analyzed using minimum inhibitory concentrations, bacterial inhibition ring tests, and detection of silver ions in the suspensions. Furthermore, the amounts of silver ions in suspensions with/without bacterial cells were analyzed. Results revealed that only a portion of released silver ions could be adsorbed by E. coli cells, which are critical to cell death. The damaged microstructures of E. coli cells observed by transmission electron microscopy may further prove that the adsorbed silver ions play an important role in the antimicrobial process.
Keywords: Silver-loaded Inorganic Materials; Antimicrobial Agent; Antimicrobial Activity; Released Silver Ions; Escherichia coli
Economical synthesis of complex silicon fertilizer by unique technology using loess by Moon Young Yoon; Sora Lee; Ji Hoon Choo; Hyeonsoo Jang; Wonwoo Cho; Hoduck Kang; Jung-Keug Park (958-963).
Loess processed material (LPM) was produced as a substitute for silicon, clay and minerals, and applied to tomato and cucumber cultivation. LPM was produced by using a NaOH addition ratio of 30%, a reaction temperature of 1,200 °C, a reaction time of 1 h, and an alumina ball diameter of 10 mm. Treatment with a 200-fold diluted LPM solution resulted in respective increase of 7.8% and 8.3% in the weight and quantity of the tomato fruit, and a 31.7% increase in the quantity of cucumber fruit produced, when compared to the control. On the other hand, commercial silicon fertilizer (CSF), with a price that is estimated to be four times that of LPM, did not significantly increase the yield of tomato or cucumber in terms of weight or quantity. Thus, it is suggested that LPM may be used as a potential complex silicon fertilizer.
Keywords: Economical Synthesis; Loess; Loess Processed Material; Production Conditions; Silicon Fertilizer
Preparation and characterization of epoxidized microbial oil by Dan Yang; Lian Xiong; Bo Wang; Xuefang Chen; Can Wang; Chao Huang; Hairong Zhang; Haijun Guo; Xinde Chen (964-971).
The potential of microbial oil derived from yeasts through fermentation using crops biomass for the formation of plasticizers was investigated. Plasticizers were formed via epoxidation reaction. Five factors of the orthogonal experiment (reaction temperature, time, weight ratio of H2O2/MO, H2SO4/MO, and HCOOH/MO) have been used for optimization of parameters. To further enhance the iodine value of microbial oil and increase the epoxy value of the epoxide, an amount of soybean oil was added. The products were characterized by FTIR, 13C-NMR and 1H-NMR. Under the optimum condition, the epoxy value and the iodine value of epoxide product were 6.21% and 1.8 g I2/100 g with a yield of 91.86% at an oil conversion of 98.43%. This study successfully demonstrated the conversion of crops biomass into value-added chemicals using simple and conventional chemical reactions.
Keywords: Microbial Oil; Plasticizer; Iodine Values; Epoxy Value; Crops Biomass
Engineering a chimeric malate two-component system by introducing a positive feedback loop in Escherichia coli by Irisappan Ganesh; Murali kannan Maruthamuthu; Soon Ho Hong (972-975).
Previous studies constructed a chimeric MalKZ two-component system to sense environmental malate. In this study, we used a positive feedback loop to accelerate and amplify the output signal indicating malate concentration. The positive feedback loop was constructed by cloning ompR gene, which encodes ompC and induces OmpR protein; ompC promoter was used to control the process. The transcriptional expression profile showed that the expression level of ompC gene increased about two-fold after the positive feedback loop was introduced. When GFP was used as a reporter protein, a 71% increase in fluorescence level was observed. The results indicate that the signal transduction kinetics of MalKZ can be engineered by introducing the positive feedback loop.
Keywords: Escherichia coli ; Malate; Positive Feedback Loop; Two-component System
Adsorption properties of silica surface-grafted with a salicylhydroxamic acid-functionalized polymer toward lead ions by Ruixin Wang; Meina Xie; Hongjing Wang; Xiaohui Shi; Caiping Lei (976-985).
Salicylhydroxamic acid (SHA), functionalized composite chelating adsorbing material SHA-PHEMA/SiO2, was prepared through the nucleophilic substitution reaction of 5-chloromethyl-salicylhydroxamic acid with poly (2- hydroethyl methacrylate) (PHEMA) modified silica gel particles PHEMA/SiO2. The SHA-PHEMA/SiO2 composites were characterized by FT-IR, scanning electron microscopy, X-ray photoelectron spectroscopy and nitrogen absorption. The adsorption behavior, adsorption thermodynamic, and adsorption mechanism of SHA-PHEMA/SiO2 for Pb2+ ions were studied, and the pH value of the medium on the adsorption property and chelating adsorption ability of SHA-PHEMA/SiO2 for Pb2+ ions was also investigated. The experimental results show that SHA-PHEMA/SiO2 possesses strong chelating adsorption ability for Pb2+ ions, and the adsorption capacity for Pb2+ ions at 308K reached 57 mg/g. The adsorption process is a chemical adsorption process driven by entropy, and the adsorption capacity increases with rising temperature. In pH range that can inhibit the hydrolysis of heavy metal ions, increasing the pH value of the medium strengthens the adsorption ability of SHA-PHEMA/SiO2 toward Pb2+ ions. The adsorption behavior is monomolecular and follows Langmuir isotherm. The adsorption capacity is almost the same after ten consecutive adsorption- desorption experiments of SHA-PHEMA/SiO2 for Pb2+ ions, indicating that SHA-PHEMA/SiO2 has excellent elution property and reusability.
Keywords: Salicylhydroxamic Acid; Poly (2-Hydroethyl Methacrylate); Silica Gel; Chelation; Lead Ions
Analysis of thermophysical property data of HI x components for I2 crystallizer design in sulfur-iodine process to produce hydrogen by Byung Heung Park; Kyoung-Soo Kang; Jeong Won Kang (986-996).
I2 crystallization could be a technical option in HI decomposition section of SI thermochemical water splitting process to increase process efficiency. Design of a crystallizer requires experimental data as well as corresponding equations for thermophysical properties of HI x solution, which is a named ternary solution of H2O, HI, and I2. However, so far, there are no available analyses on them. We collected experimental data and corresponding equations with temperature parameters and compared the equations with the data to analyze their accuracy and credibility. Thermal conductivity was updated in this work while keeping a structure of a corresponding equation. Relative deviations were estimated for liquid density, thermal conductivity, viscosity, and heat capacity and summarized with temperature for H2O, HI, and I2. Solution density and viscosity of binary H2O-HI solution were also analyzed with an empirical equation under a limited condition and with predictable methods exhibiting satisfactory consistency.
Keywords: SI Process; Hydrogen Production; Thermophysical Properties; Iodine; Hydrogen Iodide
Optimization of PES/ZnO mixed matrix membrane preparation using response surface methodology for humic acid removal by Abdul Latif Ahmad; Abdullah Adnan Abdulkarim; Suzylawati Ismail; Ooi Boon Seng (997-1007).
The application of response surface methodology (RSM) in preparation and optimization of membranes is important in order to reduce the effort and time needed to achieving an optimum performance. RSM was used to develop an optimum polyethersulfone (PES)/ZnO mixed matrix (MM) membrane for humic acid removal. The MMs were synthesized by dispersing various amounts of hydrophilic ZnO nanoparticles (NPs) into a solution containing PES, polyvinylpyrrolidone (PVP) and dimethylacetamide (DMAc). Flat sheet MM membranes were prepared via the phase inversion method using the central composite design (CCD). The effects of four preparation parameters, such as PES, ZnO, PVP weight percentages and solvent evaporation time, were investigated. Pure water flux (PWF), humic acid flux (HAF) and humic acid rejection (HAR) were selected as a model responses. It was shown that PES and PVP were mainly affected on both PWF and HAF. Furthermore, the interaction effect between PES and ZnO-NPs shows a significant effect on PWF, while the quadratic effects of both solvent’s evaporation time and ZnO-NPs weight percentage coupled with the interaction effect between PES and PVP weight percentage shows the most significant parameters that affects HAR. The optimization method was subjected to maximize all of the PWF, HAF and HAR. It was also determined that the optimized membrane can be synthesized from a solution containing 17.25 wt% PES, 3.62 wt% ZnO and 3.75 wt% PVP with 15 s of solvent evaporation time. The optimum values of PWF, HAF and HAR were 222.3 (L/m2 h), 94.7 (L/m2 h), and 96.34%, respectively. Thus, it can be concluded that the CCD technique is capable of optimizing PES-ZnO membrane performance.
Keywords: Mixed Matrix Membrane; Zinc Oxide Nanoparticles; Humic Acid; Central Composite Design
Regeneration mechanism of CeO2-TiO2 sorbents for elemental mercury capture from syngas by Kunzan Qiu; Wenhui Hou; Jinsong Zhou; Shuaiqi Meng; Xiang Gao (1008-1013).
The characteristics of mercury desorption on spent CeO2-TiO2 (CeTi) sorbents were investigated to improve the cyclic regeneration removal activity. Mercury was significantly released in the form of elemental mercury at temperatures ranging from 250 to 280 °C. Mercury desorption had a significant correlation with regeneration temperature, but was independent of the heating rate and regeneration conditions. The optimal regeneration temperature was 500 °C. The CeTi sorbents could be easily restored by simple heating and exhibited superior activity over several capture- regeneration cycles. The amount of released mercury almost equaled the adsorbed mercury on the surface of the CeTi sorbent, indicating that most of the adsorbed mercury was released during the heating process.
Keywords: Mercury; Regeneration; Syngas; Removal; CeO2
Prediction of power consumption and performance in ultrafiltration of simulated latex effluent using non-uniform pore sized membranes by Amira Abdelrasoul; Huu Doan; Ali Lohi; Chil-Hung Cheng (1014-1027).
Tha aim of the present study was to develop a series of numerical models for an accurate prediction of the power consumption in ultrafiltration of simulated latex effluent. The developed power consumption model incorporated fouling attachment, as well as chemical and physical factors in membrane fouling, in order to ensure accurate prediction and scale-up. This model was applied to heterogeneous membranes with non-uniform pore sizes at a given operating conditions and mem- brane surface charges. Polysulfone flat membrane, with a membrane molecular weight cutoff (MWCO) of 60,000 dalton, at different surface charges was used under a constant flow rate and cross-flow mode. In addition, the developed models were examined using various membranes at a variety of surface charges so as to test the overall reliability and accuracy of these models. The power consumption predicted by the models corresponded to the calculated values from the experimental data for various hydrophilic and hydrophobic membranes with an error margin of 6.0% up to 19.1%.
Keywords: Modeling; Power Consumption; Membrane Fouling; Transmembrane Pressure; Ultrafiltration
Effect of CO2-laser irradiation on properties and performance of thin-film composite polyamide reverse osmosis membrane by Foad Jahangiri; Seyyed Abbas Mousavi; Fathollah Farhadi; Vahid Vatanpour; Behnam Sabzi; Zeinab Chenari (1028-1036).
CO2-laser irradiation was used to modify the surface properties of thin-film composite (TFC) polyamide reverse osmosis (RO) membranes. These membranes were first synthesized via interfacial polymerization of m-phenylenediamine (MPD) monomers and trimesoyl chloride (TMC) over porous polysulfone ultrafiltration support, followed by a CO2-irradiation. AFM, ATR-FTIR, SEM and contact angle measurements were used to characterize the surface properties of these membranes. The ATR-FTIR results indicated that CO2-laser irradiation did not induce any functional groups on the membrane surface. However, it was found that the laser irradiation enhanced the NaCl salt rejection and slightly reduced the permeate flux. Moreover, the maintenance of the flux in modified membranes was much higher than untreated ones. Specially, after 180 min of filtration, the reduction in initial flux for the unmodified membranes was 22%. However, the reduction in initial flux for the modified membranes was less than 5%. Bovine serum albumin (BSA) filtration revealed an improvement in the antifouling properties of the modified membranes. The changes in the membrane surface morphology showed that the roughness of membrane surface is reduced significantly.
Keywords: CO2-laser Irradiation; Polyamide Membrane; Surface Modification; Fouling Reduction
Surface modification of cation exchange membranes by graft polymerization of PAA-co-PANI/MWCNTs nanoparticles by Mahsa Nemati; Sayed Mohsen Hosseini; Ehsan Bagheripour; Sayed Siavash Madaeni (1037-1046).
Surface modification of polyvinylchloride based heterogeneous cation exchange membrane was performed by graft polymerization of PAA and PAA-co-PANI/MWCNTs nanoparticles. The ion exchange membranes were prepared by solution casting technique. Spectra analysis confirmed graft polymerization clearly. SEM images illustrated that graft polymerization covers the membranes by simple gel network entanglement. The membrane water content was decreased by graft polymerization of PAA-co-PANI/MWCNTs nanoparticles on membrane surface. Membrane transport number and selectivity declined initially by PAA graft polymerization and then began to increase by utilizing of composite nanoparticles in modifier solution. The sodium and barium flux was improved sharply by PAA and PAAco- 0.01%wt PANI/MWCNTs graft polymerization on membrane surface and then decreased again by more increase of PANI/MWCNTs nanoparticles content ratio in modifier solution. The electrodialysis experiment results in laboratory scale showed higher dialytic rate in heavy metals removal for grafted-PAA and grafted-PAA-co-PANI/MWCNTs modified membrane compared to pristine one. Membrane areal electrical resistance was also decreased by introducing graft polymerization of PAA and PAA-co-PANI/MWCNTs NPs on membrane surface.
Keywords: Surface Modification; Heterogeneous Cation Exchange Membrane; Polyacrylic Acid-co-PANI/MWCNTs Composite Nanoparticles; Ionic Transport Property; Heavy Metal Removal
Chemical potential and solid-solid equilibrium of near-spherical Lennard-Jones dumbbell crystal by Sangwon Lee; Minkyu Kim; Jaeeon Chang (1047-1058).
We studied the orientational order-disorder transition of crystals made up of near-spherical Lennard-Jones dumbbells, of which reduced bond lengths are 0.225, 0.250 and 0.275. Various techniques of Monte Carlo (MC) simulations are used to calculate the chemical potentials of ordered and disordered crystals, and thereby to predict orderdisorder phase transition. First, we performed NPT MC simulations to determine crystal structure, equilibrium positions and orientations of the molecules. We then calculated the free energies of the crystals using the expanded ensemble MC simulations combined with the Einstein-molecule method and the thermodynamic integration method. The solid-solid phase equilibrium is determined from the free energy profiles of the individual phases by equating the chemical potential. The predictions of phase transition obtained from the conventional NPT MC simulation and the free energy simulation were in excellent agreement with each other, which confirms the validity of the present method of calculating the chemical potential of crystal. In addition, the Gibbs-Duhem integration was performed to obtain a complete coexistence curve between the two crystal phases. Orientational probability distributions of molecular axes were analyzed to find the characteristic behavior of rotational motion of molecule in the crystal. At sufficiently low temperature, flipping rotation of molecule in the ordered crystal is suppressed. In contrast, the flipping rotation occurs at higher temperature close to the transition while orientationally ordered structure is still maintained. In the freeenergy calculation, such a unique rotational behavior requires to use a suitable form of external rotational potential with proper symmetry number. The present study demonstrates how one can judiciously choose a correct simulation scheme for the calculation of chemical potentials of molecular crystals.
Keywords: Free Energy; Entropy; Crystal; Lennard-Jones; Symmetry Number
Combined operation of outlet streams swing with partial-feed in a simulated moving bed by Kyung-Min Kim; Ji-Yeon Song; Chang-Ha Lee (1059-1069).
The operational strategy of outlet streams swing (OSS) operation combined with partial-feed (PF) operation, OSS-PF, was studied under the constraint of maximum allowable pressure and flow-rate. Its separation performance and dynamic behavior were compared with those of OSS operation and conventional simulated moving bed (SMB) chromatography. During OSS-PF operation, the switching period consisted of two steps; raffinate was produced during the closed condition of extract node and feed node in the first step, while extracts were produced and feeds were injected during the closed condition of raffinate node in the second step. As a result, OSS-PF operation could be performed under the allowable maximum flow-rate in the corresponding conventional SMB without generating an additional pressure drop at the adsorbent bed, which was different from OSS operation. OSS-PF operation successfully improved the separation performance of the conventional SMB with regard to extract purity, raffinate recovery and raffinate productivity with equivalent eluent consumption. The step ratio during a switching period worked as one of important operating variables in separation performance. The dynamic behavior of OSS-PF operation was analyzed and compared with that of OSS and conventional SMB using simulated concentration profiles in the fluid phase.
Keywords: Simulated Moving Bed (SMB); Outlet Streams Swing (OSS); Partial-feed; Pressure Drop
Enhanced moisture-barrier property and flexibility of zirconium oxide/polymer hybrid structures by Se Hee Lim; Seung-Woo Seo; Eun Jung; Heeyeop Chae; Sung Min Cho (1070-1074).
New zirconium oxide (ZrO2)-based organic-inorganic multilayers were fabricated and tested for flexible moisture barriers and compared with typical aluminum oxide (Al2O3)-based multilayers. We report that amorphous ZrO2 had a better intrinsic barrier property than that of amorphous Al2O3. Due to the lower elastic modulus of ZrO2, the ZrO2-based structures had better flexibility than that of the Al2O3-based structures. The ZrO2-based barrier was superior to the Al2O3-based barrier not only for flexibility but also for barrier performance. The barrier property and flexibility of the ZrO2-based structures were enhanced by about 20% and 30% over those of the Al2O3-based structures, respectively.
Keywords: Moisture Barrier; Atomic Layer Deposition; Aluminum Oxide; Zirconium Oxide
Facile synthesis of bimetallic Ni-Cu nanoparticles using liquid phase plasma method by Seung Han Sun; Sang-Chul Jung (1075-1079).
A liquid phase plasma (LPP) process was used to synthesize of Ni-Cu bimetallic particles in aqueous solution. The bimetallic particles were well separated, and the particle size increased with increasing LPP process duration, causing these bimetallic particles to be well separated as the particle size increased when the LPP process time increased. The earliest stages of LPP formed dendrite-shaped nanoparticles, while spherical particles were generated in the later stages. While spherical Ni-Cu bimetallic nanoparticles were mostly observed in the initial stage, flower-like shaped Ni-Cu bimetallic nanoparticles were mostly observed after longer durations of plasma treatment. The solution pH decreased with increasing LPP process time.
Keywords: Liquid Phase Plasma; Bimetallic Nanoparticle; Nickel; Copper
Green plasticizers derived from soybean oil for poly(vinyl chloride) as a renewable resource material by Puyou Jia; Meng Zhang; Lihong Hu; Yonghong Zhou (1080-1087).
Vegetable oil based plasticizers have potential use as nontoxic and sustainable plasticizer and as replacements for commonly used phthalate plasticizers. In this study, novel soybean oil based polyol esters (derived from glycerin or pentaerythritol, of which two were acetylated and two were additionally epoxidized) were synthesized and characterized with GPC, FT-IR and 1H NMR. Properties of poly (vinyl chloride) (PVC) plasticized with different soybean oil based polyol ester as main plasticizer were evaluated and compared to that of traditional plasticizers dioctyl phthalate (DOP) and epoxidized soybean oil (ESO). It has been proved that thermal stability of PVC blends could be improved by soybean oil based polyol ester plasticizers. Plasticizing effect of pentaerythritol derived soybean oil polyesters on PVC is better than that of DOP, ESO, and glycerin derived soybean oil polyesters. Tests of migration stability showed that with the increasing of the molecular weight, branching degree of molecular and ester bands of soybean oil based polyol ester, the migration stability was enhanced. This study may lead to the development of new type of PVC materials using soybean oil based polyol ester as main plasticizer.
Keywords: Poly (vinyl chloride); Soybean Oil; Plasticizer; Thermal Property; Migration Resistance
Constructing polyurethane foams of strong mechanical property and thermostability by two novel environment friendly bio-based polyols by Shuping Huo; Guomin Wu; Jian Chen; Guifeng Liu; Zhenwu Kong (1088-1094).
Two novel cardanol-based polyols were synthesized and used to construct polyurethane (PU) foams. The cardanol-based polyols with high reactivity were obtained from the epoxidation of cardanol, followed by the ring opening reaction of epoxy group with diethanolamine (DEA). Subsequently, PU foams were synthesized by these cardanolbased polyols. Compared with petroleum-based (PEG) PU foams, these green cardanol-based PU foams exhibit better mechanical property and higher thermostability. Scanning electron microscopy (SEM) tests show that the cells of cardanol-based PU foams are monodisperse, with fairly uniform spherical shape and regular size.
Keywords: Bio-based Polyols; Polyurethane Foam; Cardanol; Mechanical Properties; Thermogravimetric Analysis (TGA)
Multiwalled carbon nanotubes and fluoroelastomer antistatic nanocomposite for automotive fuel system components by Young Seok Lee; Seong Hwan Park; Jong Cheol Lee; Kiryong Ha (1095-1103).
Fluoroelastomer (FKM) composites, reinforced with multiwalled carbon nanotubes (MWNTs), were prepared by conventional method to determine the possibility of using MWNTs to develop an antistatic composite in automotive fuel systems. The results obtained from the composite containing 0-9 phr of MWNTs were compared. A 5 points increase in hardness was achieved with the addition of only 1 phr of MWNTs and 9 phr added FKM composite was increased 6.4MPa in tensile strength compared to the MWNTs unfilled FKM composite. In addition, electrical conductivity increased from 0 to 1.039 Scm−1 with increase in the MWNTs concentration, and the dynamic damping property was increased in the rubbery state region accordingly. These phenomena can be explained by the MWNTs networks formed in FKM matrix. This research will therefore be useful in the development of an antistatic rubber composite for fuel system components, which are deformed or vibrated while in operation.
Keywords: Carbon Nanotube; Antistatic Nanocomposite; Fluoroelastomer; Mechanical Property; Electrical Property
Rheology, mechanical properties and crystallization behavior of glycidyl methacrylate grafted poly(ethylene octene) toughened poly(lactic acid) blends by Yan Zhao; Ye Zhang; Zonglin Li; Hongwei Pan; Qinglin Dong; Lijing Han; Huiliang Zhang; Lisong Dong (1104-1114).
Poly(lactic acid) (PLA)/poly(ethylene octene) grafted with glycidyl methacrylate (POE-g-GMA denoted as GPOE) blends were prepared via simple melt compounding method at GPOE loadings from 5 to 20wt%. GPOE can significantly affect the physical properties of PLA. Compared to neat PLA, the elongation at break and impact strength of the blends were significantly improved. Scanning electron micrograph analysis revealed large numbers of cavities in the fracture surface of the blends, and the size of the cavities increased along with the increase of GPOE content in the PLA/GPOE blends. Furthermore, the overall crystallization rates were faster in the PLA/GPOE blends than that in neat PLA. However, the crystallization mechanism and crystal structure of these blends remained unchanged despite the presence of GPOE. The addition of GPOE decreased the degree of crystallinity of PLA. The toughened PLA could be of great use and importance for wider practical applications.
Keywords: PLA; GPOE; Blends; Mechanical Properties; Crystallization
Preparation and characterization of docetaxel self-nanoemulsifying powders (SNEPs): A strategy for improved oral delivery by Sharath Sunkavalli; Basanth Babu Eedara; Karthik Yadav Janga; Ashok Velpula; Raju Jukanti; Suresh Bandari (1115-1124).
Liquid self-nanoemulsifying drug delivery systems (L-SNEDDS) of docetaxel were prepared using varying ratios of Capmul PG 8 NF (oil), Cremophor EL (surfactant) and Transcutol-P (co-surfactant). The optimized L-SNEDDS (L11) was transformed into self-nanoemulsifying powder (SNEP) by physical adsorption on to Neusilin US2 and evaluated for dissolution behavior, in vitro cytotoxicity and in vivo oral bioavailability. Optimized L-SNEDDS (L11) composed of 50% of oil, 41.7% of surfactant and 8.3% co-surfactant produced stable emulsion with smaller globules (43±3 nm). In vitro dissolution studies showed the rapid drug release within 5min (95.42±1%) from SNEP N . In vitro cytotoxicity assessed by the MTT assay using MCF-7 human breast cancer cell lines revealed that L-SNEDDS significantly reduced the IC50 value and was 2.3 times lower than the pure docetaxel. Further, the oral bioavailability studies in male Wistar rats showed higher C max values following treatment with SNEP N (0.98±0.13 μg/mL) and L-SNEDDS (1.09±0.06 μg/mL) compared to pure docetaxel (0.37±0.04 μg/mL).
Keywords: Docetaxel; Liquid Self-nanoemulsifying Drug Delivery Systems; Self-nanoemulsifying Powders; Oral Bioavailability; Cytotoxicity