查看更多>>摘要：This work reports the fabrication of magnetic polymer dimers with controlled surface anisotropy. The fabrication process involves the preparation of magnetite (Fe3O4) magnetic clusters with strong magnetism, followed by their surface modification, dispersion polymerization while using them as seeds, multilayer shell formation via layer-by-layer deposition, and polymer core swelling. The interplay between the swelling and multilayer shells generates pressure inside the multilayer-deposited, magnetic polystyrene (PS) spheres, forming structurally anisotropic dimers with single PS protrusions anchored on the multilayer surfaces within minutes. The use of titania precursor and different swelling agents, along with the change in the composition of the multilayer shell, enables the introduction of different surface anisotropies, such as the surface-charge anisotropy, anisotropic hydrophilicity/hydrophobicity, and material composition anisotropy, to the dimers. The strong magnetic response of the dimers, attributed to the magnetic cluster seeds, in combination with the surface-charge and material composition anisotropies allows a rapid magnetic recovery and an excellent reusability, enabling their application to 20-cycled reduction of 4-nitrophenol (4-NP) and methylene blue (MB) without loss of catalytic activity. Furthermore, the anisotropic hydrophilicity/hydrophobicity makes the dimers potentially useful as solid surfactant to stabilize immiscible oil-water mixture. (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 article presents an application of curcumin, a widely available and cost-effective organic dye, to control visible-light mediated ATRP. A two-component photocatalytic system composed of curcumin and an amine-based electron donor activates alkyl bromide and controls radical polymerizations by a reductive quenching pathway. The polymerizations of various types of (meth)acrylates were performed under blue LED irradiation (lambda(max) = 460 nm, 5 mW cm(-2)). The effect of electron donor type, solvent, photocatalyst and electron donor concentration, target degree of polymerization (DPtarget) etc. on the metal-free ATRP of methyl methacrylate (MMA) and poly(ethylene glycol) methyl ether methacrylate (OEGMA(500)) was systematically investigated to optimize the polymerization conditions. Moreover, comestible curcumin of four different brands available in the market as kitchen spices was used, which makes this approach economical (similar to 0.04 (sic) for 15 g of turmeric). In order to increase the applicability of the curcumin-based polymerization strategy, the concept was extended to the polymerization of other methacrylates - butyl methacrylate (nBMA), di(ethylene glycol) methyl ether methacrylate (DEGMA), 2-(dimethylamino) ethyl methacrylate (DMAEMA), and acrylates i.e. poly(ethylene glycol) methyl ether acrylate (OEGA(480)), n-butyl acrylate (nBA) and 2-hydoxyethyl acrylate (HEA). In situ chain extension experiment demonstrated the preservation of chain-end functionality, enabling the facile synthesis of well-controlled copolymers. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Kim, KwanghwiPark, Hyun SicLim, HyunjiKang, Jo Hong...
11页
查看更多>>摘要：The SO2 absorption/desorption performances of 14 aqueous amino acid solutions were evaluated to identify efficient absorbents to remove SO2 from coal-powered plant emissions. SO2 absorption/desorption experiments were conducted at 298.15 and 373.15 K, respectively, using 600 ppmv SO2 (N-2 balance) and N-2 purging. Thereafter, the absorption/desorption loadings and rates of the solutions, as well as their net cyclic capacities, were compared. The SO2 absorption mechanisms were explored via C-13 NMR, H-1 NMR, and UV-Vis analyses, and the relationship between the pKa values and absorption performances of the 14 aqueous amino acid solutions was investigated. Furthermore, the effects of absorption temperature, absorbent concentration, and inlet SO2 concentration on the SO2 absorption performances of the solutions were explored. 5-Aminovaleric acid, 4-aminobutyric acid, beta-alanine, and histidine were identified as suitable SO2 absorbents based on their absorption/desorption performances and their net cyclic capacities. Furthermore, the net cyclic capacities of these four absorbents were similar or superior to those of previously reported deep eutectic solvents and ionic liquids. The results of this study provide a strategy for preparing eco-friendly SO2 absorbents. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Lee, Hong JooLee, Seung HwanMagnone, EdoardoShin, Min Chang...
11页
查看更多>>摘要：The present work is the first detailed description of the endothermic catalytic reaction of methylcyclohexane (MCH) over H-ZSM-5 zeolites (HZ) and activated charcoals (AC) coated in a multichannel micro-reactor module with novel ultra-compact wavy structure (MR) under supercritical conditions (550 degrees C, 5 MPa). The MR has an ultra-compact structure with nine micro-channels in parallel that exhibit a size of 120 x 30 mm and a total cross-sectional area of 36 cm(2). The catalytic performance of the conventional tube reactor (TR) packed with HZ and AC catalysts was also studied for comparative purposes. All catalysts and reactors were characterized using various techniques such as field emission scanning electron microscope (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), ammonia temperature-programmed desorption (NH3-TPD). In general, MRs showed always a significantly enhanced MCH conversion (%) performance and heat sink compared with conventional TRs. AC-coated MR showed the highest MCH conversion (%) performance compared to the other reactors. MCH conversion (%) was higher in the following order AC-coated MR (78.70%) > AC-packed TR (70.49%) > HZ-coated MR (68.87%) > HZ-packed TR (54.81%). The AC-coated MR can be one of the candidates for a heatabsorbing reaction for aircraft cooling system control. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Lee, Tae HeonKim, Hye JeongLee, Bo-RaLee, Sang Bong...
7页
查看更多>>摘要：The unique ability of chlorophyll derivatives to accumulate in tumor tissues and cause a photodynamic effect under laser radiation has been successfully used in photodynamic therapy (PDT). Previous research on modified peripheral substituents in chlorophyll showed that the presence and position of substituents in chlorin derivatives remarkably affect biological activities. Herein, we synthesized methyl pyropheophorbide-a (MPPa) derivatives, which are chlorophyll-a derivatives with heterocyclic aromatic substituents or pyrazole moieties on the peripheral positions. Then, we examined the PDT effects of these new derivatives in vitro and in vivo. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：Zinc oxide nanoparticles (ZnO NPs) were prepared by a facile, one-pot, greener approach using aqueous leaf extract of the medicinal plant Nuna (Morinda tinctoria) and were analyzed by ultraviolet-visible (UV-Vis) and Fourier-transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) techniques. The TEM images confirmed that the as-prepared greener Nuna (Nu)-mediated ZnO NPs (Nu-ZnO NPs) were spherical in shape, with an average diameter of 8-10 nm. Further, the single phase and crystallinity of the Nu-ZnO NPs were observed by PXRD pattern. In addition, the biogenic Nu-ZnO NPs showed high cytotoxicity in human breast adenocarcinoma (MCF-7) cells in vitro. These tiny spherical bodies produced profound toxicity according to the MIT assay, with IC50 of 46 mu g/mL. Apoptosis and morphological changes were studied using acridine orange/ethidium bromide and 4',6-diamidino-2-phenylindole fluorescence staining and MTT assays. Finally, the anticancer efficacy of biosynthesized Nu-ZnO NPs was imparted by dysregulation of cell division through arrest of growth-promoting and inhibiting signals in the S phase, with further reduction in the G2/M phase of the cell cycle. In conclusion, Nu-ZnO NPs conferred MCF-7 cell toxicity by modulating proliferation and inducing apoptosis. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：For industrial purposes and current challenges facing the world, the selective separation of oxygen and nitrogen gases from the air by polymer mixed matrix membranes is crucial. Due to the diamagnetic nature of water molecules used in the fabrication of the polymer membranes, the magnetic field (H) may affect the resulting separation performance. Here, using a simultaneous co-casting method, empty and superparamagnetic Fe3O4 nanoparticle-filled double-layer polyethersulfone (PES)/Pebax (R) 1657 mixed matrix membranes are fabricated under different external magnetic field intensities in the range of H = 0-5000 Oe. The O-2 and N-2 permeances of the PES/Pebax (R) membranes are found to increase with increasing the magnetic field intensity, arising from an enhancement in the polymer chain mobility. The Fe3O4 nanoparticles form thick root-like superparamagnetic channels on the double-layer PES/ Pebax (R) surface at a magnetic field intensity of 4000 Oe, resulting in an O-2/N-2 ideal selectivity of 3.59 at a feed gas pressure of 10 bar. This indicates an improvement of 40% in the selectivity compared to a single-layer Pebax (R) membrane filled with Fe3O4 nanoparticles. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Hussain, MuridShezad, NasirShafiq, IqrashMaafa, Ibrahim M....
10页
查看更多>>摘要：A visible-light active N,S-codoped TiO2 incorporated with carbon nanotubes (CNTs) was synthesized by a multicomponent heterojunction scheme. The synthesized photocatalysts was examined by several analysis techniques. The conventional TiO2, N-doped TiO2, TiO2/CNT and N,S-codoped TiO2 were also synthesized, characterized, and integrated adsorptive-photocatalytic degradation rates were subsequently compared and assessed, for comparative purposes as reference photocatalysts. The parametric study was also carried out to investigate the effect of various operational factors, such as solution pH, the photocatalyst loading and initial concentration of dye solution, on the adsorptive-photocatalytic performance. The best activity performance was attained with the N,S-TiO2/CNTs nanocomposite due to the synergistic effect of ternary components caused by the incorporation of dopants and CNTs in TiO2 lattice, providing a high number of adsorption sites and facilitating the effective separation of photogenerated charge carriers and minimal recombination rates. N,S-TiO2/CNTs exhibited around three times higher photocatalytic performance than that of the binary composites, i.e., N-TiO2, TiO2/CNTs, N,S-TiO2, and about four times higher than the conventional TiO2. Furthermore, the superior nanocomposites were also investigated for their recyclability for five consecutive cycles. (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 study, a porous polyurea/graphene platelet (GnP) composite film with high flexibility and multi functionality was developed and investigated for strain sensing and energy storage applications. Morphology and mechanical properties were studied; tensile strength and Young's modulus were enhanced by 132% and 900%, respectively at 5 wt% GnPs. The polyurea/GnP film exhibited high sensitivity to various strains- namely, tension, compression, bending and twisting. In tensile strain, gauge factor was 1.86 and 6.26 within strain ranges of 0-30% and 30-60%, respectively. Interestingly, the film showed piezoresistive and capacitive-type strain sensor under compression load; a 33% increase in relative resistance with response time of 108 millisecond; and 22% increase in relative capacitance with response time of 92 millisecond when load of 5 kPa was applied. Furthermore, the strain sensor showed high durability and reliability over 20,000 cycles. The developed polyurea/GnP film showed a stable capacitive performance over 20,000 charge-discharge cycles. This work provides important insights for the potential of polyurea/graphene films in multifunctional sensors and flexible energy storage applications. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
查看更多>>摘要：With growing interest in the bulk production of the alternative energy carrier hydrogen, dry-reforming of methane using carbon dioxide has attracted great interest as one of the possible carbon capture and utilization (CCU) technologies and hydrogen production methods. An integrated system combining the dry-reforming and water gas shift reactions is suggested to improve the productivity of hydrogen, and a system has also been developed for high-purity hydrogen production from a single system using the sorption-enhanced reaction concept. To realize the proposed system, we develop the Ru-doped Sr0.92Y0.08TiO3 perovskite catalysts and investigate their characteristics using various analyses. The prepared catalysts exhibit excellent CH4 conversion of 92.2% for the dry-reforming reactions at 800 degrees C without performance degradation by coke formation. Moreover, high-purity hydrogen (>99.5%) is directly produced by the proposed integrated system using anthropogenic greenhouse gases as reactants, and the efficiency is further enhanced by recycling the captured CO2 to the dry-reforming reactor. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
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