查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryIn this study, a three-dimensional chitosan/mesoporous silica composite material (I-CTS-KIT-6) was successfully synthesized by one-step method using ion imprinting technology. To overcome the enormous cost problem, MoO42? with similar radius to ReO4? was selected as template ion. In addition, the adsorbent was prepared by using glutaraldehyde and chitosan as crosslinking agents and monomers and TEOS as silicon source in the process of imprinting. The effects of pH values, mass of chitosan and template ion, contact time, temperature and concentration on Re(VII) adsorption were studied. The results revealed that the I-CTS-KIT-6 has the saturated adsorption capacity of 368.8 mg g?1 at pH 3.0 for Re(VII), and the adsorption process corresponded to Langmuir isotherm and pseudo-second-order kinetics. Especially, the I-CTS-KIT-6 has higher selectivity for rhenium ions compared with the non-imprinted adsorbent. To verify the adsorption mechanism, density functional theory (DFT) was adopted to analyze the binding patterns of Re(VII) with the I-CTS-KIT-6. The test analysis and calculation results further mentioned that the adsorption mechanism is mainly three N atoms of I-CTS-KIT-6 coordinated with three oxygen atoms of ReO4?, which provides the theoretical foundations and explanations for adsorption process.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryIn the process of coal seam water injection, the components of different fracturing fluids have different effects on coal. To analyze the effect of water injection fracturing fluid on the physical and chemical properties of coal, we studied the relationship between guar-based fracturing fluid and cationic clean fracturing fluid (C-VES). Microscopic experiments show that guar-based fracturing fluid has a certain viscosity effect on coal, while C-VES can adsorb and capture the primary coal dust in coal. FTIR analysis shows that C-VES has a great change on the content of coal functional groups, and guar-based fracturing fluid has little effect on coal. Industrial analysis shows that C-VES can better reduce the ash content of coal and has a certain impact on the thermal efficiency of coal than guar based fracturing fluid. Combustion characteristic experiment shows that guar-based fracturing fluid does not affect the combustion effect of coal, and C-VES can expand the exothermic temperature range of coal but has little effect on the main combustion of coal. Molecular dynamics simulation results show that C-VES has the best wetting effect on coal. This research provides theoretical guidance for dust prevention and improving the use and conversion efficiency of coal.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe energy storage properties of layered metal vanadate, especially alkali metal vanadates have been extensively studied. Metal vanadates have a more robust electrochemical output in contrast with pristine vanadium oxides. However, the detailed processes underlying the efficiency contrast of vanadates and vanadium oxides have rarely been studied. Herein a facile hydrothermal and low-temperature polymerization method was introduced to synthesize KV3O8 and KV3O8@PPy nanowire bundles as anode material for an aqueous rechargeable Lithium batteries. The nanowires are composed of KV3O8·0.59H2O calculated using thermal gravimetric analysis (TGA). Successfully synthesized layered vanadium based KV3O8 0.59H2O (KVO) and KV3O8 0.59H2O@PPy (KVO@PPy) nanowires and investigated the source of the improved electrochemical efficiency of PPy coated potassium vanadates compared to pristine KVO using crystal structure analysis and electrochemical tests. We demonstrated increase in electrochemical stability for KVO@PPy caused by synergistic effect of K+ in vanadate nanowires and PPy coating. In KVO the oxygen atoms have close contact with the K ions, and the stable K+ serve as “pillars” between interlayers to shield the layered structures from collapse during the charge/discharge phase, while the PPy reduces charge transfer resistance. This research adds helps us design better electrode materials to be used as an anode material for ARLB using alkali metal vanadate.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryIn the Ultrafiltration (UF) region, the development of the membranes with ultra-water permeability and extraordinary oil rejection at the same time is highly desirable. Herein, a copolymer/nano-hybrid particles mixed matrix membrane was fabricated with high hydrophilicity and oil-in-water separation performance, originating from the synergistic effect between the prepared copolymer and nanoparticles. Accordingly, atom transfer radical polymerization (ATRP) method, especially considered as a promising grafting technique to modify polyvinylidene fluoride (PVDF), was utilized for the synthesis of the PVDF-g-PMMA copolymer. Furthermore, two different nano-hybrid particles including graphene oxide (GO) sheets separately decorated with ZnO and SiO2 were also synthesized. Then, different membrane compositions with various GO@ZnO and GO@SiO2 contents were fabricated, and then, the synergistic effect of each nano-hybrid particle with the PVDF-g-PMMA copolymer was evaluated. The prepared GO@ZnO and GO@SiO2 were used not only to modify ultrafiltration (UF) membranes for oil rejection but also to prevent protein BSA adsorption on the membrane surface based on their surface charge. The 4 wt.% PVDF-g-PMMA/0.3 wt.% GO@SiO2 and 4 wt.% PVDF-g-PMMA/0.3 wt.% GO@ZnO membranes provided outstanding separation performance (soybean oil rejections of 93.4% and 95.2%, respectively) and ultra- water permeability (312 and 326 L/m2.h.bar, respectively). Based on the results in terms of separation and filtration performances, the M5 membrane exhibited more efficient performance than M4 membrane. By increasing the amount of nano-hybrid particles, the overall finger-like voids, average pore size, and surface roughness of membranes decreased, making them ideal for application in the water treatment field. Also, the influence of hydrophilicity and charge density of GO@ZnO and GO@SiO2 nano-hybrid particles with the copolymer in the PVDF membrane was examined through conducting the antifouling experiment in two different pH values, in which a great performance was also obtained. Compared to previous researches, GO@ZnO and GO@SiO2 nano-hybrid particles with the copolymer in the PVDF membrane not only can generate ultra-high water permeability in low pressure but also provide >93% oil-in-water emulsion rejections.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryTo exploit the benefits of membrane-based separation for the pharmaceutical and chemical industries, the understanding of membrane fouling in organic solvents is crucial. Specifically for the separation of biocatalysts in the manufacture of pharmaceuticals, this study investigated membrane fouling by bovine serum albumin (BSA) in 10% v/v isopropanol (IPA), 10% v/v dimethyl sulfoxide (DMSO), 30% v/v IPA, and 30% v/v DMSO, benchmarked against that in water. The presence of either IPA or DMSO worsened fouling, with the latter comparatively worse. To understand the fouling mechanisms, Field Emission Scanning Electron Microscopy (FESEM) images were taken to assess external fouling, Evapoporometry (EP) was used to measure the pore-size distributions of the fouled membranes to examine internal fouling, a fouling model was applied to extract the fouling parameters, and the interfacial interaction energies were derived. Results indicate that the worst fouling in 30% v/v DMSO was due to both significant external fouling and internal fouling, whereas the second-worst fouling by 30% v/v IPA was caused predominantly by internal fouling. The magnitudes of the total DLVO- and XDLVO-based interaction energies were found to be poorly related to the relative flux declines. This study provides valuable insights into membrane fouling in different solvent environments.
查看更多>>摘要：? 2022Designing Ni-based catalyst with high performance is one of the most important challenges for operation of practical steam-methane reforming (SMR) processes. We report control of the textural properties of commercial alumina ball for Ni-supported catalysts in SMR. The textural properties of the commercial Al2O3 sphere are successfully controlled by aqueous HCl treatment for elongated periods. The pore diameters and pore volumes of the controlled alumina supports are finely tuned by varying the HCl treatment period. The catalytic activity of the corresponding Ni-supported alumina is significantly enhanced with increasing HCl treatment period on alumina ball. The alumina supports with longer HCl treatment period have larger pore size and bigger pore volume, and the corresponding Ni-Alumina catalysts exhibited higher catalytic activity at even higher space velocity, due to the increased intraparticle diffusion of reactant molecules inside the catalyst. Ni-supported alumina catalyst prepared by using alumina support treated with HCl for 18 h showed the largest pore size and pore volume, revealing enhanced catalytic activity in terms of CH4 conversion and H2 yield. It showed the well-maintained activity without any further deactivation in both continuous operation for 24 h and cyclic operation at different WHSV conditions.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryZinc–air batteries (ZABs) have drawn attention recently as alternatives to conventional Li-ion batteries because of their high energy density, abundance in the earth's crust, and relatively low production cost. Although ZABs are incredibly stable under normal conditions unlike popular Li-based energy storage devices, many challenging issues remain. Requirements such as rechargeability, low-cost fabrication, and mass production of an effective bifunctional catalyst restrict the use of commercial ZABs to a few small electronic gadgets. In this study, we introduce a functionalized pen-drawable ink composed of amorphous MnO2 with a large specific area, graphene sheet (GS) flakes, and poly(3,4-ethylenedioxythiophene) (PEDOT). The MnO2-decorated GS is successfully immobilized on graphite felt (GF) using the PEDOT network. The pen-drawn MnO2@GS/PEDOT/GF substrate is further used as a bifunctional air cathode. Power density of the air cell is 37.8 mW·cm?2 at 55 mA·cm?2. The potential difference between the half-wave potential of the oxygen reduction reaction and the operational potential of the oxygen evolution reaction is 0.74 V; this value is comparable to that of traditional noble metal catalysts, and is obtained at a current density of 10 mA·cm?2 with the pen-drawn cathode in a two-electrode system containing a conventional 6 M KOH electrolyte.
查看更多>>摘要：? 2022In this study, the pressurized liquid extraction (PLE) of total phenolic content (TPC), gallic acid (GA), and p-hydroxybenzoic acid (PHBA) from Pseuderanthemum palatiferum (Nees) Radlk. leaves was optimized using response surface methodology. The extract at the optimum conditions of TPC, namely OP, was characterized using GC–MS, HPLC, and spectrophotometry analysis. Furthermore, bio-functional properties of the OP, including antioxidant, antimicrobial, antihypertensive activities, and cytotoxicity against cancer and normal cell lines, were also investigated. The results showed that all extraction models were appropriate in predicting the extraction processes (p < 0.05) of the target compounds. In addition to TPC, GA, and PHBA, the OP also contains a high amount of other valuable components that contributed to its highly biological activities. Moreover, the OP was nontoxic on HaCaT cells with a concentration of no more than 1000 μg/mL. From the obtained results, PLE proved to be a suitable technique for the recovery of bioactive compounds from P. palatiferum leaves.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryIn the present study, quantum confinement effect in phosphorene and black phosphorus quantum dots is extensively studied from experimental and theoretical viewpoints. These quantum structures were prepared with the help of Benzonitrile solvent using Liquid Phase Exfoliation and solvothermal-assisted Liquid Phase Exfoliation, respectively. On one hand, Fourier-transform infrared spectroscopy shows no sign of phosphorus oxidation in both phosphorene and black phosphorus quantum dots solutions. Furthermore, Raman spectroscopy showed a shift in B2gandAg2 phonon modes for phosphorene and black phosphorus quantum dots as compared to bulk black phosphorus. On the other hand, structural characterization via high-resolution transmission electron microscopy imaging and electron diffraction patterns showed a high degree of crystallinity in both quantum structures with no sign of aggregations. Optical properties characterization showed the expected increase in the bandgap value for both quantum structures, which were supported by theoretical calculations using density functional theory and effective mass approximation. Interestingly, we demonstrate that the quantum confinement observed in phosphorene is weakened to the expected extent, relative to that in BPQDs, by the loss of two confinement dimensions. Appropriate models, describing the bandgap and effective mass dependence as a function of the confinement regime, are presented.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryAlthough the metal loading sequence can highly influence the bimetallic catalyst performance, they are generally applied to the reaction experiments without investigating the metal impregnation sequence. In this study, therefore, we investigated the surface properties of CeO2-promoted Mn/TiO2 catalysts with different impregnation sequences of Mn and Ce in the low-temperature selective catalytic reduction (SCR) of NO by NH3. We observed that the catalyst performance depended on simply changing the impregnation method of Mn and Ce in the catalyst activity test for the low-temperature SCR reaction. The co-impregnated catalyst, Mn-Ce/TiO2, achieved much higher NO conversion than other catalysts. Additionally, X-ray diffraction, transmission electron microscopy, N2 adsorption/desorption experiments, H2 temperature-programmed reduction (H2-TPR), NO/NH3 temperature-programmed desorption (NO/NH3-TPD), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) were performed to identify the influence of this simple change on the catalyst. These characterization results indicated that metal dispersion improved in the co-impregnated catalyst compared to the sequentially impregnated catalysts, and these well-distributed metal particles (Mn-Ce/TiO2 catalyst) could produce defect formation on the catalyst, thereby serving more NOx/NH3 adsorption sites. Moreover, it was found that catalyst acidity could be simply controlled by changing synthesis method although it contained same metal composition. This knowledge will be useful for the design of catalyst for low temperature NH3-SCR of NO.
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