查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe disposal of leather waste has always been a huge challenge facing the tannery. Thus, the effective conversion of leather waste into value-added products can help the leather industry achieve green and sustainable development. In the paper, we utilized collagen hydrolysate (CH) obtained from leather waste as a protein retarder for gypsum and the effect of CH on the setting, hydration and crystallization process of gypsum was analyzed. The results showed the addition of CH delayed the increase in hydration degree and release of hydration heat during the hydration process of gypsum, and this delay action was more remarkable as more CH was introduced. Moreover, CH could postpone the crystallization of dihydrate gypsum from a micro perspective. TG/DSC, FTIR, XRD, and SEM analysis indicated that the presence of CH inhibited the hydration reaction hemihydrate gypsum and the formation of dihydrate gypsum but over time the hemihydrate gypsum was completely hydrated at last. Finally, the retardation mechanism of CH on the gypsum was investigated by adsorption and zeta potential measurements. Adsorption and zeta potential measurement results demonstrated that CH could inhibit the hydration process of hemihydrate gypsum by adsorbing on the gypsum particle, thereby achieving the retarding effect.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThere is an urgent need to build effective and environmentally friendly photocatalysts due to environmental pollution caused by primarily organic molecules. Bismuth tungstate (Bi2WO6) nanocomposites have a wide range of compositions and morphologies, making them intriguing materials for environmental applications. Hierarchical Strontium-based Bismuth tungstate (Sr-Bi2WO6) catalysts made from these nanocomposites have improved photocatalytic effectiveness against organic contaminants. We created hierarchical strontium-based bismuth tungstate (Sr-Bi2WO6) composites using a single-step hydrothermal synthesis process. Fourier-transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, ultraviolet–visible diffuse reflectance spectra, specific surface area, and X-ray photoelectron spectroscopy were used to characterize the synthesized catalysts. The photocatalytic activity of hierarchical 15% Sr-Bi2WO6 composites for both the reduction of p-nitrophenol (4-NP) and degradation of methylene blue (MB) under UV light is outstanding. When reducing 4-NP to 4-aminophenol (4-AP) in the presence of NaBH4, the 15% Sr-Bi2WO6 catalyst demonstrated good catalytic activity and recycling properties. In comparison to pristine Bi2WO6, 5% Sr-Bi2WO6, 10% Sr-Bi2WO6, photocatalyst containing 15% Sr-Bi2WO6 perform exceptionally well, degrading 99.5 percent MB in 25 minutes and 99.4 percent 4-NP reduction in 15 minutes under UV light and NaBH4, respectively. This remarkable increase in photocatalytic activity could be attributed to the fact that Sr2+ may aid charge carrier separation by trapping Sr ions and creating oxygen vacancies.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe catalytic activity of structured catalysts comprising Fecralloy and SiC monoliths coated with Ru/Mg-Al oxide by deposition–precipitation was evaluated in the partial oxidation of natural gas and compared with that of a conventional pellet catalyst. The geometric surface area (GSA) of the Fecralloy and SiC monolithic catalysts were 377.0 × 10-4 and 118.5 × 10-4 m2, respectively; significantly larger than that of the 0.5% Ru/Al2O3 pellet catalyst (89.6 × 10-4 m2). Owing to the high GSA of the structured catalysts, a small amount of Ru (0.070–0.12 wt%) resulted in highly dispersed uniform loading. Thus, the structured catalysts exhibited higher performance for catalytic partial oxidation at varying C/O2 ratio, inlet temperature, and gas hourly space velocity (GHSV) than the pellet catalyst. However, in a stability test at high GHSV (50,000 h?1), the CH4 conversion of the Fecralloy monolithic catalyst decreased rapidly from 90% to less than 70% in 150 min. In addition, the Mg-Al oxide layer of the Fecralloy monolithic catalyst was damaged owing to material deterioration, resulting in a loss of Ru particles. In contrast, CH4 conversion catalyzed by the SiC monolithic catalysts remained above 85% even after 1000 min, and the material or support layer was not damaged even under severe conditions.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryFabrication of biocompatible scaffolds that can facilitate the mending of damaged tissue has attracted much attention. In this study, the preparation and structural investigation of a curcumin-loaded Fe(II) metal–organic framework/polydimethylsiloxane sponge, Cur/Fe-MOF/PDMS, are reported. Various techniques such as FTIR (Fourier-transform infrared), XRD (X-ray diffraction), SEM (scanning electron microscope), TEM (transmission electron microscope), EDS (energy-dispersive X-ray spectroscopy) mapping, and XPS (X-ray photoelectron spectroscopy) have been used to investigate the as-fabricated materials. Results confirm the successful incorporation of curcumin and Fe-MOF into the PDMS matrix. The obtained SEM images indicate the sponge-like structures of the PDMS and the Fe-MOF/PDMS composite. Indeed, the results from in vivo show animals all to be survived without any unusual responses to the transplant. According to macroscopic observation, the Fe-MOF/PDMS and Cur/Fe-MOF/PDMS scaffolds seem better confederates than the pure PDMS. H&E staining has confirmed enhanced healing and revascularization in the Cur/Fe-MOF/PDMS than the PDMS and Fe-MOF/PDMS scaffolds. Additionally, a two-stage profile was observed for the release of curcumin into PBS (phosphate-buffered saline) solution. The hydrophilic property of the Fe-MOF resulted in fast release at the first stage. These results exhibit that the Cur/Fe-MOF/PDMS sponge can serve as a 3D porous substrate in the tissue engineering (TE) field.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe alloying strategy of Pt with Ni is commonly employed to improve the catalytic activity of electrocatalysts owing to the higher activity required to lower the binding energy of oxygen with Pt. When Pt is alloyed with Ni, electron transfer from Ni to Pt is conducive to metallic Pt, lowering the oxygen binding energy. Although the alloying strategy can increase the catalytic activity, confirming that the surface state has the intended electronic structure is difficult because of the oxidation or dissolution of metals. To determine the surface state of catalyst nanoparticles for a more efficient structure, the concept of physical blocking of the reactive surface was applied to determine the geometric effect. The oxygen reduction reaction in phosphoric acid electrolytes is more sensitive to the geometric effect due to anion adsorption. In this work, we synthesized carbon-supported PtNi alloying nanoparticles with different carbon shell thicknesses (PtNi@Cx; x = 0.5, 1, 2, 4, where x refers to the concentration of the surfactant) from various concentration of organic surfactants. Among the nanoparticles with various carbon shell thicknesses, PtNi@C2 showed the best oxygen reduction reaction performance in the presence of phosphoric acid with an appropriate geometric effect, ensuring a synergetic effect with alloying.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryHerein, we report a successful resolution of L-norvaline, a racemic compound system, performed near the eutectic composition by coupling preferential crystallization with tailor-made additives. The structures of enantiomer and racemate were characterized by PXRD, DSC, and the enantiomeric purity were measured by Chiral HPLC. The preferential crystallization process was designed and established from binary melting phase diagram and ternary solution phase diagram. The effects of supersaturation, solution enantiomer composition, and seed quantity on the preferential crystallization process were investigated. However, the significant improvements of enantiomeric purity and product yield were demonstrated by additive-assisted preferential crystallization approach using tailor-made additives. These additives bearing similar structure motifs to norvaline a highly selective binding to the racemate rather than enantiomer and remarkably suppress nucleation of DL-norvaline, the key factor determining the resultant enantiomer purity and separation efficiency. The underly inhibition principle was revealed due to the centrosymmetric packing of the racemate while the polarity of enantiomer leads to only partial or slight crystallization suppression. The interesting inhibition mode by tailor-made additives is also believed to be applicable for other racemic crystallization systems. Our established additive-assisted preferential crystallization has showed great potential in the development of separation technology and resolution of enantiomer from racemic compounds.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryDue to the high redox ability and effective separation of photocharges, Z-schemed photocatalysts have been extensively used to deal with energy crises and environmental pollution. Here, a novel Z-schemed g-C3N4/RGO/ln2S3 photocatalyst was designed and prepared for hydrogen generation and tetracycline hydrochloride degradation. The properties of optical absorption, separation, and transfer of photocharges and heterojunction on photocatalytic activity of g-C3N4/RGO/ln2S3 composite have been studied. The characterization results showed that the Z-scheme photocatalyst has high efficiency on the separation and transfer of photocharges, and the strong redox ability has also remained. Thus, the g-C3N4/RGO/ln2S3 composite exhibited superior photocatalytic performance than pristine ln2S3 and g-C3N4 in the same situations. The H2 evolution rate can reach up to 512.72 μmolg-1h?1 and the degradation of tetracycline hydrochloride can reach 95.6% in 60 min under visible light irradiation. This work provides a potential pathway for designing and preparing high-performance photocatalysts to produce clean energy and purify the environment.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThe volume transition of thermo-responsive hydrogels has been investigated for various applications such as soft actuators, sensors, drug delivery systems, and bioelectronics. Nonetheless, issues such as poor mechanical properties, slow transition rates, and limited volume change windows have prompted the development of hydrogel composites. Gallium (Ga), a liquid metal, is combined with poly(N-isopropyl acrylamide) (PNIPAm) with varying composite structures in this work. Ga's melting point is close to PNIPAm's volume transition temperature. The introduction of Ga particles into PNIPAm improves both the indentation resistance and the transition rate of the hydrogel. Microchannel structure can further improve the transition rate by increasing the water diffusion rate. The relatively fast thermal conduction of the Ga phase in anisotropic composites causes fast deswelling of Ga-rich regions, resulting in unique double bending behavior. The double bending behavior was utilized to hold irregularly shaped objects firmly. These results offer a useful design strategy of composites for the development of novel responsive smart systems.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryBisphenol A (BPA) is identified endocrine-disrupting compounds (EDCs) that is detected in water resources. The intrinsic properties of nanoclays favor to stimulate the combination of sieving and electrostatic interaction mechanisms during the removal of BPA using membrane separation. Herein, the synthesised hydrophilic bentonite-polyaniline (B-PANI) and cloisite 15A-polyaniline (C-PANI) was loaded individually into polyethersulfone (PES) for fabricating mixed matrix membranes (MMMs). The PANI nanoclays was presented in both surface layer and inside pores of nanocomposite membranes at 0.5, 1 and 1.5 wt% loading. The results showed the enhancement in surface hydrophilicity for all the membranes in loading of PANI nanoclays. The presence of B-PANI influenced the higher water flux of 82.2 Lm-2h?1 at 1.5 wt%, indicating hydrophilic property. YBP2 MMM with 1 wt% B-PAN depicted higher BPA rejection efficiency of 77.2 %. B-PANI bestow the MMM with hydroxyl and amine functional groups which retard the transport of hydrophobic BPA through the hydrophilic MMM. Further, higher BPA rejection was ascribed to the electrostatic repulsion between MMM surface and BPA. The fouling mechanism was identified by Hermia model that represents YBP2 membrane revealed cake filtration fouling model with reversible fouling. This work highlights the feasibility of B-PANI in MMM for BPA removal from water.
查看更多>>摘要：? 2022 The Korean Society of Industrial and Engineering ChemistryThis work presents novel natural-based and solvent-free additives for poly(vinyl chloride) (PVC), namely calcium soaps, obtained for the first time from naturally occurring epoxidized soybean and linseed oils (ESO/ELO); and biogenic calcium carbonate, obtained from chicken eggshells (EG) after different acid and/or thermal pre-treatments. Results show that these additives were able to: i) reduce the concentration of volatile organic compounds released from PVC films, including alcohols, aldehydes, esters and phthalates (97,95,90 and 84% chromatographic peak area reduction, respectively), originating safer materials; ii) improve the long-term thermal stability of PVC-based materials, while maintaining their mechanical performance and when compared to control samples formulated with a high-performance commonly employed solvent-based thermal stabilizer. Films formulated with ESO-based calcium soaps and with EG powders treated with acid and thermal treatment (200 °C) presented the best performance in terms of heat aging and long-term thermal stability. The former also slightly improved the thermomechanical properties of the films indicating that these additives are also working as secondary plasticizers for PVC. This work gives an important contribution towards the safety and sustainability of high-performance PVC-based materials, by allowing the substitution of commercially available thermal stabilizers by new eco-friendlier and safer alternatives obtained from renewable sources.
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