Kim, KyungjunKang, Dong WooYun, Chan YeongChoi, Youngheon...
11页
查看更多>>摘要：This study investigates reaction kinetics of high-pressure amination of polyalkylene glycol (PAG) to polyetheramine (PEA). The reductive amination of PAG was carried out depending on the NH3 amount, reaction temperature, reaction pressure, and H2O content in a batch reactor to understand the effect of these factors on activity and selectivity toward the primary amine. Contrary to the fact that the amination step is a zero-order reaction and dehydrogenation of alcohol to ketone is the rate-limiting step in the reductive amination of alcohol, the amount of NH3 significantly affected the reaction rate. The increased amount of NH3 enhanced the activity and selectivity for PEA, in contrast with the results reported in prior studies. A Langmuir-Hinshelwood kinetic model was established to reflect the effect of the NH3 amount, and kinetic parameters such as the rate constant and activation energy were obtained at a high pressure around 150 bar. It was also found that the absence of NH3 caused the reverse reaction of PEA to the secondary amine in the presence of H2. The fundamental kinetic analysis provides a competitive synthesis route for improving the activity and selectivity toward the primary amine. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：Herein, we synthesized 1D bimetallic hydrogen phosphate [CoxNix(HPO4)] nanorods by using a simple and effective chemical bath deposition method for supercapacitor applications. The prepared CoxNix(HPO4) was analyzed by Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) pattern. The surface morphology was envisaged by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. The porous nature and surface area of the materials were characterized by nitrogen sorption isotherm and a high specific surface area of 153 m2 g-1 was found to be for Co0.75Ni0.25(HPO4). The Co0.75Ni0.25(HPO4) displays a maximum specific capacity of 475 mA h g-1 at 1 A g-1 in a three-electrode configuration using 3 M KOH as the electrolyte. Co0.75Ni0.25(HPO4) exhibits almost 94.8% of its initial specific capacity over 5000 GCD cycles at 10 A g-1. Furthermore, the fabricated asymmetric supercapacitor (ASC) with Co0.75Ni0.25(HPO4) and activated carbon (AC) showed a high specific capacitance of 182.5F g-1 at 0.5 A g-1. The ASC device delivered a maximum energy density of 64.88 Wh kg-1 at a power density of 800 W kg-1. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Sudhaik, AnitaKhan, Aftab Aslam ParwazRaizada, PankajAsiri, Abdullah M....
16页
查看更多>>摘要：Growing pollution and high energy demand are some of the major issues against humans. Water pollution is one of the main problems created due to industrial waste and irresponsible human activities. Nowadays, photocatalysis is rising as an efficient alternative to overcome the energy requirement and water purification, as it can use solar light as a source of energy. Due to some limitations of photocatalysts, such as photocarriers recombination, low surface area, and limited light absorption, modifications such as defect modifications, heterojunction can be employed. Out of all, Z-scheme heterojunction is a proficient way to overwhelm the limitation of pristine photocatalysts. To enhance the activity of Z scheme photocatalyst, even more, a dual Z-scheme photocatalytic scheme has been developed in which two Z-scheme based charge transfer occur simultaneously on a ternary photocatalyst. In this review, we have discussed the different types of dual Z-schemes along with their application in water purification and finally, we have discussed the future prospects for further research. CO 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Kang, Eun-kyungHan, Dong JeLee, Byung MinBae, Jin Woo...
6页
查看更多>>摘要：To obtain superior surface-active properties while minimizing environmental risks, new fluorinated surfactants (F2HX-nEO) were designed to include a hybrid multi-chain with a short fluorocarbon (-CF2CF3) and nonionic ethylene oxide. They were simply synthesized by a straightforward reaction involving the addition of ethylene oxide to a hybrid fluorine alcohol, and their surface-active properties were optimized by controlling the hydrocarbon length and number of ethylene oxide units. Therefore, the desirable values of critical micelle concentration (0.3 mmol/L) and surface tension (24.3 mN/m) were obtained in spite of containing the short fluorocarbon chain. Particularly, F2HX-nEO showed excellent wetting properties on hydrophobic surfaces and very low toxicity level, which can be used in various fields as a promising alternative to long fluoroalkyl chain surfactants. (c) 2021 The Authors. Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).
Park, HangilChoi, Jae-HwanBae, Kyeong WooMun, Sungyong...
12页
查看更多>>摘要：Galactotriose (G3), which is contained in a crude galacto-oligosaccharides (GOS) mixture coming from enzymatic transgalactosylation reactions, is known to have potential as a high-grade prebiotic ingredient. This has aroused an interest in the high-purity recovery of G3 from a crude GOS mixture, which included monosaccharides (galactose and glucose), disaccharides (G2), and GOS components with different degrees of polymerization (G3, G4, and G5). To settle this problem, we aimed to develop an efficient simulated-moving-bed (SMB) process for high-purity recovery of G3 from the crude GOS mixture. It was found first that the appropriate column temperature and ionic form of the adopted adsorbent in consideration of both G3-G2 and G3-G4 resolutions were 65 degrees C and K+ form respectively. Under such adsorbent conditions, the equilibrium constants and mass-transfer parameters of the crude mixture components were determined and then exploited in the design of the G3-recovery SMB, which was carried out with a priority focus on the stable maintenance of high purity for G3 product throughout the SMB operation. The separation performance of such designed SMB was verified on the bases of the column profiles from simulations and the outlet-concentration data from the relevant SMB experiment. Overall, it was confirmed that the designed SMB could recover G3 from the crude GOS mixture in a continuous mode with a purity of more than 98.9% while keeping the overall loss of G3 below 7.3%. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：It is urgent to control serious drug pollution and heavy metal ion pollution. Covalent organic framework (COF) is becoming a promising material for the removal of heavy metal ion and adsorption of organic small molecule because of the designed functional sites, ordered pore channel, high specific surface area and abundant pi electrons. Herein, 2,4,6-triformylphloroglucinol (TFP) and benzene-1,3,5-tricarbohydrazide (BTH) was used to design a stable yet efficient beta-ketoenamine COF (COFTFP-BTH) adsorbent, which would provide multiple adsorption sites of Hg2+ by dense acylhydrazine. The maximum adsorption capacity of COFTFP-BTH toward Hg2+ achieved 909 mg g(-1), coinciding with Langmuir adsorption and pseudo-second-order adsorption kinetic model, with the h value as high as 71.43 mg g(-1) min(-1). COFTFP-BTH was also grown on NH2-carbon nanotubes (CNT) to form a novel COFTFP-BTH@NH2-CNT com-posite for sensitive detection of nitrofural (NF). The NF sensor based on COFTFP-BTH@NH2-CNT showed a low detection limit (3.2 nM) and a wide linear range (9.6 nM-100 mu M). The excellent performances were also attributed to the ordered channels of COFTFP-BTH exposing more adsorption sites of Hg2+ and NF, as well as the good stability of beta-ketoenamine COFTFP-BTH. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：The electron transport layer (ETL) plays an important role in high-efficiency perovskite solar cells (PSCs). TiO2 nanorod (TNR) thin film with outstanding photovoltaic properties is considered as an excellent ETL in the structure of PSCs. To enhance the efficiency of PSCs, ETL heterostructures with anatase TiO2 nanoparticles (TNPs) and rutile TNRs are fabricated and optimized by two-step hydrothermal process. The maximum efficiency of PSCs based on the ETLs of TiO2 heterostructures in this study is 14.143%, which is much higher than that of PSC cell with the ETL of pure TNRs (9.361%). Hypothesis: This study aims to prepare TiO2 heterostructures with two different polymorphic TiO2 (anatase TNPs and rutile TNRs) for high-performance PSCs. Experiments: TiO2 heterostructures are prepared on conductive FTO substrate by two-step hydrothermal process. Commercial TNPs (P25) are used in different heterostructures for comparison. The structural, morphological characteristics and the current-voltage properties of these ETLs are carefully investigated. Findings: The enhanced performance of TiO2 heterostructures-based PSCs is believed to be attributed to the excellent capability of carrier extraction, large surface area, light scattering effect and defect passivation at the ETL/perovskite interface. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：A new strategy for preparing a novel CaO-Al2O3 auxiliary electrode coating for sulfur sensor by infiltrating Ca2+ and Al3+ into the porous ZrO2(MgO) backbone was proposed in this work. The phase composition and microstructure of the auxiliary electrode was detected and correlated to the electrochemical perfor-mance, while the application of the sulfur sensor in the liquid iron was presented. It is demonstrated that the CaO-Al2O3 particles were homogenously coated on the ZrO2(MgO) backbone and formed well con-nected network, which could effectively improve the reaction area between CaO-Al2O3 and [S] as well as enhancing the ionic conductivity and bonding strength of the auxiliary electrode. The assembled sulfur sensor possessed a superior sensing performance of theoretical response, simultaneously the Nernst rela-tionship between the sensor EMF output and the linearity of the sulfur concentration occurred along with the stable, continuous, and reproducible response. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Heidari, Ali AkbarMahdavi, HosseinKahriz, Peyman Khodaei
11页
查看更多>>摘要：Solvent resistant nanofiltration (SRNF) is now a powerful tool for addressing environmental issues. Hence, we report the fabrication of a thin film composite (TFC) membrane comprised of a novel HDPE support, a polydopamine (PDA)/Tannic acid-Fe(III) interlayer and a polyamide (PA) skin layer. In this respect, high density polyethylene (HDPE)-polystyrene (PS)-styrene-ethylene-butylene-styrene (SEBS) blends were formed with different compositions by mixing via a Brabender machine and making films by using a hot press instrument. Next, a solvent extraction technique was employed for extracting the dispersed phase and making the HDPE membranes. The support membrane with optimum properties was coated with a PDA interlayer. A tannic acid-Fe(III) interlayer was also formed on the as-prepared PDA layer so that the hydrophilicity of the support surface was enhanced to form a defect-free PA layer. The modified support was utilized for the fabrication of the PA top layer by using m-phenylene diamine (MPD) and trimesoyl chloride (TMC) monomers. The prepared TFC membrane provided a significant dye rejection ability (99.9% Direct Yellow, 99.7% Methyl Green, 99.2% Rhodamine B, and 96.1% Methyl Orange), extraordinary solvent resistance ability in harsh solvents, and good methanol (MeOH) Flux (2.25 L/m(2).h.bar) in SRNF applications. The skin-substrate adhesion strength of the top layer was also evaluated by a back-ward flush operation. It was demonstrated that the interlayer and the skin layer had an excellent adhesion with the support membrane. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：In this research, to prepare a polymer membrane with hydrophilic nature that has anti-fouling and anti-adhesion properties first, polyvinyl imidazole (PVI) Polymer was bonded as a surface modifier of fluorinated polyvinylidene (PVDF) membranes by Atom transfer radical polymerization (ATRP) method. Therefore, to confirm the chemical changes of the hydrophilic membrane surface such as PVI polymer chain bonding and to investigate the uniform distribution of the polymer in the modified membrane pores and surface, experiments such as attenuated general reflectance (ATR-FTIR), nuclear magnetic resonance (H-NMR), Water contact angle (WCA) and scanning electron microscopy (SEM), zeta potential, Atomic force microscopy (AFM) spectroscopy, Thermo-gravimetric analysis (TGA), X-ray energy scattering (EDX), X-ray diffraction (XRD) patterns were performed. The results showed that the WCA for M1 membrane was about 83.37 +/- 1.77 and M(b)6 membrane was about 35.45 +/- 1.45, which improved the WCA rate of M(b)6 membrane surface by about 57.10%. Therefore, the total Anti-fouling rate and Flux recovery ratio (FRR) and rejection oil rate increased by about 35.2%, 18.65% and 10%, respectively. This study aimed to investigate the surface modification of membranes prepared with hydrophilic polymer PVI to separate oil from the oil-in-water emulsion, which is a suitable method and potential approach in controlling large-volume oil-in-water emulsion effluents. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
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