查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryPd-incorporated Zr-based metal–organic framework containing sulfone groups, named Pd(II)BUT-11, was successfully prepared by dispersing the sulfone-functionalized MOF in Pd(OAc)2 solution. X-ray diffraction, scanning electron microscopy, N2 isotherm sorption, X-ray photoelectron spectroscopy, and thermogravimetric analysis were applied to determine the features of the Pd-incorporated MOF. In the catalytic studies, Pd(II)@BUT-11 was shown to be an efficient heterogeneous catalyst for synthesizing various stilbene derivatives via the cross-coupling Heck reaction with DABCO-derived deep eutectic solvent (DES) as a green solvent. Notably, the catalyst and the solvent could be recovered and reused, with their activity and structure remaining stable throughout several trials. The method provides an alternative solution to the conventional catalysts and solvents, resulting in a green and efficient stilbene synthesis process. Furthermore, the stilbenes were separated by extraction with ethyl acetate due to the low solubility of DES with this solvent.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryNanoparticles (NPs) with responsive modalities in biological microenvironments and external stimuli have received great attention as highly efficient and precise cancer therapy agents. In this study, tumor intracellular microenvironment-responsive NPs co-assembled from poly(ethylene glycol)-poly(aspartic acid) [PEG-P(Asp)] copolymer, doxorubicin (DOX), and superparamagnetic iron oxide NPs (SPIONs), termed as PEG-P(Asp)/DOX/SPIONs, were prepared for tumor intracellular microenvironment (enzyme and pH)-responsive and magnetically targeted chemotherapy. The NPs exhibited not only enzyme-responsive degradation in the presence of protease, but also triggered release of DOX at pH 5, which is an acidity similar to endolysosomal microenvironments in tumor cells. Furthermore, the PEG-P(Asp)/DOX/SPIONs showed a contrast effect in magnetic resonance imaging. In vitro viability assays showed that PEG-P(Asp)/DOX/SPIONs could effectively augment the cytocompatibility of DOX compared to free DOX without a change in magnetic forces. Fluorescence microscopy images indicated that the fabricated NPs efficiently increased the targeted uptake and release of DOX within cells. Overall, this hybrid NP system could be a favorable biomedical agent for effective tumor-targeted anti-cancer therapy.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryCu-δ-Bi2O3 nanosheets with uniform thickness of approximately 2.7 nm and length about 200 nm for photocatalytic nitrogen fixation and photocatalytic oxidation is achieved by simple hydrothermal method. The 2D ultrathin structure is benefit to the formation of the surface oxygen vacancies, meanwhile the impurity defect is formed due to the substitutive Cu doping of δ-Bi2O3. The as-prepared 5% Cu-δ-Bi2O3 exhibits excellent NH4+ generation rate of 142.8 μmol h?1 g?1 without any sacrificial agent irradiated by visible light. The remarkable photocatalytic ability can be attributed to the ultrafast carriers transfer from the interior to the surface because of 2D ultrathin structure feature, the separation of electrons-holes and molecular chemisorption due to the formation of surface oxygen vacancies and impurity defect.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryIn this study, a N-functionalized porous carbon derived from ZIF-8 (NFPC) was prepared and applied for the gaseous acetone and toluene adsorption removal. The NFPC perfectly inherited the morphology of parent ZIF-8, posed a high specific surface area (SBET = 1228 m2·g?1), be rich in surface nitrogen functional groups, and resulting in a good dynamic adsorption of the VOCs. The NFPC-1000 exhibited the best adsorption performance of low concentration acetone and toluene, with equilibrium adsorption capacity of 203.4 and 297.1 mg·g?1 at 25 °C respectively. The acetone and toluene adsorption were spontaneously and exothermic, given the negative values of free energy (ΔG) and enthalpy (ΔH). The difference of acetone and toluene adsorption on NFPC attributed to the affinity difference (boiling point, polarity and molecular diameter), the nitrogen-containing functional groups (pyridinic-N) and the cation-π bonding. Therefore, the NFPC was found to be more favorable for aromatic compounds adsorption, the toluene adsorption of NFPC-1000 only decreased 5.3% after 6 cycles reuse, while its adsorption capacity of acetone lost more than 60%.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryProlonged exposure to trace Cr(VI) concentrations in potable water can cause serious health problems in living beings. A weak base anion exchange resin, Duolite A7, showed a large capacity for trace Cr(VI) removal from a background of competing anions present at much higher concentrations, while conventional ion exchangers and adsorbents become ineffective due to lack of selectivity under similar conditions. The objective of this study was to find out the mechanism behind such significant capacity shown by the resin. Fixed-bed column studies showed that the resin was fully exhausted below 4,000 bed volumes (BVs) for pH 7, whereas no breakthrough was observed for 25,000 and 131,000 BVs at pH 5 and 3, respectively. Extensive characterization studies revealed that redox reactions were also occurring inside the resin in addition to ion exchange, where Cr(VI) oxidized the amine functional groups and phenol–formaldehyde matrix while itself getting reduced to Cr(III). Cr(III) formed was either precipitated inside the resin as Cr(OH)3 or bound with the oxidation products such as carboxylic acid groups. Analysis of treated water showed that formaldehyde, a carcinogen, was formed due to oxidative attack of Cr(VI) on the resin and was released in the effluent at trace concentrations. A detailed understanding of the mechanism would motivate the development of such redox-active sorbents for selective trace Cr(VI) removal from contaminated drinking water.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe removal of organic pollutants was examined by new zeolitic imidazolate framework-8/carboxyl-functionalized multi-walled carbon nanotubes (ZIF-8/MWCNTs-COOH) nanoadsorbents, which were prepared via controlling the reaction sequence of MWCNTs-COOH with the precursors of ZIF-8. Structural morphology and chemical composition characterizations confirmed the successful preparation of ZIF-8/MWCNTs-COOH nanoadsorbents. The obtained samples manifested a preferable adsorption capacity for Congo red with the maximum adsorption capacity of 1185.58 mg g?1 with an adsorption removal rate of 97.93% at equilibrium adsorption. Further analyses indicated that the adsorption process conformed to the pseudo-second-order kinetic model and Langmuir adsorption isotherm. The thermodynamic analyses were depicted as endothermic, entropy-increasing, and spontaneous. The effects of pH value, interfering ions, and dosage on the adsorption properties were systematically explored. The nanoadsorbent can be expediently reused for eight cycles without a prominent reduction in adsorption activity. The improved performance and high reusability can be ascribed to the increasing specific surface, the presence of electrostatic interaction, hydrogen bonding, and π–π interaction between ZIF-8/MWCNTs-COOH and organic molecules. In addition, the prepared composites also showed a better adsorption performance for tetracycline with the equilibrium adsorption capacity of 471.22 mg g?1 compared to pure ZIF-8 and MWCNTs-COOH.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryWe introduced chromium and boron into the hierarchical structure of ZSM-5 by following an incipient wet impregnation and hydrothermal synthesis approach to enhance the performance of the catalysts in the methanol-to-propylene process. Crystal structure, preferred orientation, and crystal symmetry of synthesized zeolites were discussed using Rietveld refinement and revealed that all synthesized zeolites crystallized in a monoclinic structure, whereas the boron-incorporated sample exhibited an orthorhombic symmetry. Large-scale defect-free single-crystalline structures of hierarchical zeolite created by CTAB and F127 mesoporogens are confirmed by electron microscopy and magic angle spinning nuclear magnetic resonance (MAS NMR). The formation of surface metal oxides and extra-framework metal oxides caused changes in the electronic structure of the components as visible in Si 2p and O 1s spectra. The predominant presence of OH groups and the higher Cr (VI) /Cr (III) ratio account for the better performance of impregnated chromium-ZSM-5 especially in the production of light olefins. The introduction of boron by impregnation further preserved the preferred growth orientation, hierarchical structure with high crystallinity and caused surface acidity changes in favor of increasing propylene selectivity to 67% with a propylene/ethylene ratio of close to 8.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryConstructing a high-performance photocatalyst is one of the most effective approaches to remove heavy metals from wastewater. Here, we successfully synthesized MgAl-layered double hydroxide/graphitic carbon nitride/ (CuPd/LDH/CN) decorated with CuPd bimetallic nanoparticles for the first time to photocatalytically reduce hexavalent chromium (Cr(VI)) in an aqueous solution. The ternary CuPd/LDH/CN heterojunction exhibited superior photocatalytic reduction of Cr(VI) under visible light compared to those of pure CN, LDH, and the binary composites. The CuPd bimetallic nanoparticles were deposited onto the LDH/CN surfaces, as confirmed by morphological observations. Our results revealed that unique structural features endow CuPd/LDH/CN catalysts with excellent photocatalytic performance, likely attributed to abundant active sites, large specific surface areas, as well as enhanced separation and transfer efficiencies of photo-generated charge carriers. Particularly, the nanocomposite (with LDH and CuPd contents of 15 wt% and 1 wt%) exhibited the highest catalytic efficiency with 98% removal of aqueous Cr(VI) (40 mg/L) within 40 min. Furthermore, no significant change in the degradation activity of the CuPd/LDH/CN nanocomposites was observed through four successive experimental runs. This study provides new insights into the design and construction of high-performance photocatalysts with potential applications in environmental remediation and energy conversion.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryHydrochlorofluorocarbons (HCFCs) are representative powerful greenhouse gases that contribute significantly to global warming. As an alternative strategy for their existing separation and recovery methods, hydrate-based gas separation (HBGS) has been of great. A preliminary investigation was performed to measure the hydrate phase equilibria of pure HCFC-22, pure HCFC-142b, and two different gas mixtures of these with N2 (at molar composition ratios of 8.01:12.01:79.98 and 20.01:30.00:49.99), which is indispensable to the design of a HBGS process and determination of its operating conditions. Hydrate dissociation enthalpies of the investigated systems were calculated from the measured equilibrium data using the Clausius-Clapeyron equation, and their values were 82.12 (HCFC-22), 153.65 (HCFC-142b), 127.90 (HCFC-22 8.01%), and 133.51 (HCFC-22 20.01%) kJ/mol, respectively. Their crystal structures were determined using powder X-ray diffraction, and results revealed that HCFC-22 merely formed structure I hydrate. Kinetic hydrate formation tests were carried out with the two different gas mixtures, and the compositions of the vapor and hydrate phases were examined. The hydrate nucleation and separation performance were profoundly affected by the initial system pressure, proven by showing the shortest induction time and the highest separation factor for HCFCs.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistrySkin elasticity is the most important marker of skin aging. In this study, we examined the effects of, and mechanism underlying the action of, dissolvable and swellable microneedle (MN) patches fabricated from hyaluronic acid (HA) or gelatin on skin elasticity. We observed that dissolvable HA and Gelatin MN patches exhibited higher instant skin elasticity change ratios (17.3% and 12.6%, respectively) than any other MN patches in vivo. Both the patches increased the dermal thickness by increasing the elastin levels and preventing collagen degradation by downregulating the activity of MMP-1 in the dermis. In vitro, HA and gelatin exhibited antioxidant activities and increased the viability and proliferation of rat dermal fibroblasts, thereby promoting fibroblast accumulation in the dermis. Particularly, HA-induced enlargement of the spread-out area of the fibroblasts stimulated their contractile ability. Therefore, we propose dissolvable HA as the most suitable natural polymer for MN patches to improve skin elasticity.
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Elsevier