ACS Applied Materials & Interfaces
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2017
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IF 7.504
Xiangyang Chen,Lin Gan,Zhijun Zhang,Ping Lu,Xionghui Zeng,Linlin Zhang,Heliang Yao,Fangfang Xu,Jingtai Zhao
Ca-α-SiAlON:Eu is one of the most promising phosphors exhibiting potential applications in high power LEDs owing to its excellent thermal stability and relatively high luminescence efficiency comparable to YAG:Ce commercial phosphors. The oxidation states of Eu ions in Ca-α-SiAlON:Eu are still questionable, and furthermore it exhibits lower luminescence intensity than commercial yellow phosphors. Therefore, in the present work, the valences of Eu ions in Ca-α-SiAlON have been examined, from which a mixture of divalence and trivalence is observed. Further improvement in emission intensity involves finding a way to increase the incorporation of larger Eu ions into the Ca-α-SiAlON. Here, we observed preferred doping of Eu around phosphor grain surface and then propose a surface engineering strategy involving HF pickling of glassy surface layer, formation of Eu-rich precursors, and finally post-annealing, aiming to increase surface incorporation of Eu ions. The surface engineered samples exhibit great enhancement in emission intensity with a maximum increment by 80%.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2016
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IF 3.138
Zhen-Yuan Zhu,You Luo,Guo-Ling Dong,Yuan-Yuan Ren,Li-Jing Chen,Ming-Zhu Guo,Xiao-Ting Wang,Xue-Ying Yang,Yongmin Zhang
A novel homogeneous polysaccharide fraction (APS) was extracted from Astragalus by hot water and purified by Sephadex G-100 and G-75 column. Its molecular weight was 693 kDa. APS and APS with ultra-high pressure treatment exhibited significant inhibitory abilities on a-glucosidase, inhibition rate from high to low in order was 400 MPa-APS, 300 MPa-APS, 500 MPa-APS and APS. The inhibition percentage of 400 MPa-APS (1.5 mg/mL) was 49% (max.). This suggested that the inhibitory activity of APS on a-glucosidase was improved by ultra-high pressure treatment. FT-IR, SEM, CD spectra, atomic force microscope and Congo red test analysis of APS and 400 MPa-APS showed ultra-high pressure treatment didn’t change the preliminary structure but had an effect on its advanced structure.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2016
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IF 3.138
Hui Guo,Yi Tang,Yang Yu,Lu Xue,Jun-qing Qian
Enzyme immobilized on magnetic particles can be used as efficient recoverable biocatalysts under strong magnetic response. To enable re-use of enzyme, modified Fe 3 O 4 particles were used as carrier to immobilize α-amylase in this paper. Firstly, the surface of Fe 3 O 4 particles were coated with amino groups by direct using TEOS (tetraethoxysilane) followed by treatment with APTES (3-aminopropyltriethoxysilane) and then carboxylated by reacting it with succinic anhydride. In addition, the effect of the immobilization condition on enzyme activity recovery and immobilization efficiency were investigated. The results showed that the optimal immobilization occurred under following conditions: pH 5.5, 40 °C, enzyme concentration of 20 mg mL −1 , reaction time for 36 h. Using immobilized α-amylase as biocatalyst, the optimum pH and temperature for hydrolysis were observed to be 6.5 and 60 °C. The kinetics of hydrolysis reaction were studied using Michaelis–Menten equation. The affinity constant ( K m ) and maximum reaction rate ( v max ) of magnetic particles immobilization α-amylase (MPIA) was 0.543 mg mL −1 and 1.321 mg min −1 compared to those of 0.377 mg mL −1 and 6.859 mg min −1 of free enzyme. After immobilization, enzymatic activity, storage stability, thermo-stability, and reusability of MPIA were found superior to those of the free one. MPIA maintained 86% enzyme activity after 30 days and maintained 78% enzyme activity after recycling six times.
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JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2016
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IF 2.933
Shuai Zhang,Na Sha,Zhe Zhao
Stereolithography of UV-curable ceramic suspensions can benefit from the preparation of stable, low viscosity and high solid loading ceramic suspensions without yield stress. Appropriately adding dispersants could optimize the rheological behavior to meet the requirements of stereolithography. In this work, short-chain dicarboxylic acids were utilized to modify the alumina particles and achieve well dispersed ceramic suspensions. The maximum adsorption capacities of dicarboxylic acids were determined by the method of High Performance Liquid Chromatography and the mechanism of surface modification and dispersion was also discussed. Dicarboxylic acids’ influence on the rheology behavior was systematically studied. When doses of dicarboxylic acids reach their maximum adsorption capacities, the alumina suspensions would achieve their lowest viscosities and yield stresses. 45 vol% alumina suspension with a viscosity ˂2 Pa s at shear rate 30 s −1 was successfully formulated. A sintering density of 96.5% can be achieved for the sebacic acid-modified alumina UV-curable suspension.
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FUEL PROCESSING TECHNOLOGY
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2017
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IF 3.752
Zhong-Qiu Liu,Xian-Yong Wei,Xiao Zhou,Yu-Chuan Xiao,Zhan-Ku Li,Xian-Hou Guo,Sheng-Kang Wang,Yang-Yang Zhang,Zhi-Min Zong,Feng-Yun Ma,Jing-Mei Liu
An acidic ionic liquid modified microfiber attapulgite (MFA)-supported nickel was prepared by thermally decomposing nickel tetracarbonyl onto MFA modified with an acidic ion liquid (AIL, 1-sulfobutyl-3-methylimidazolium trifluoromethanesulfonate). It was characterized with multiple instruments and used for catalyzing hydroconversion of coal-related model compounds (CRMCs) di(1-naphthyl)methane, diphenylmethane , bibenzyl, and 1,3-diphenylpropane. The results indicate that Ni/MFA@AIL effectively catalyzes hydroconversion of the CRMCs to afford cyclanes and alkylcyclanes by inducing the formation of H + , H − , and biatomic active hydrogen species.
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JOURNAL OF LUMINESCENCE
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2016
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IF 2.693
Hongna Bi,Lin Tang,Xin Gao,Jingjing Jia,Henghui Lv
We investigated the binding interaction between tetracycline hydrochloride (TCH) and bovine proteins β-casein (β-CN), α-lactalbumin (α-LA) in aqueous solution by multi-spectroscopic methods and molecular modeling techniques. Fluorescence and time-resolved fluorescence showed that TCH effectively quenched the intrinsic fluorescence of bovine proteins via static quenching, while there was a single class of binding site on protein. Thermodynamic parameters revealed that electrostatic forces played major roles in the interaction between β-CN and TCH, whereas α-LA-TCH complex were stabilized by hydrogen bonds and van der Waals forces . Moreover, circular dichroism spectra (CD spectra), ultraviolet visible absorption spectra (UV–vis absorption spectra), and fluorescence Excitation-Emission Matrix (EEM) spectra results indicated the secondary structure of bovine proteins was changed in the presence of TCH with the α-helix percentage of protein-TCH complexes decreased. Molecular modeling analysis supported the experimental results well. In addition, the research of surface hydrophobicity further verified tertiary structure of proteins was changed in the presence of TCH and the possible changes of protein function. These results achieved from experiments may be valuable in the milk industry and food safety.
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JOURNAL OF SEPARATION SCIENCE
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2017
·Vol. 40
·期 23
·4653-4660
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IF 2.557
Haoran Fan,Jinpeng Wang,Qingran Meng,Yaoqi Tian,Xueming Xu,Zhengyu Jin
Photoirradiation surface molecularly imprinted polymers for the separation of 6- O -α- d -maltosyl-β-cyclodextrin were synthesized using functionalized silica as a matrix, 4-(phenyldiazenyl)phenol as a light-sensitive monomer, and 6- O -α- d -maltosyl-β-cyclodextrin as a template. Fourier transform infrared spectroscopy results indicated that 4-(phenyldiazenyl)phenol was grafted onto the surface of functionalized silica. The obtained imprinted polymers exhibited specific recognition toward 6- O -α- d -maltosyl-β-cyclodextrin. Equilibrium binding experiments showed that the photoirradiation surface molecularly imprinted polymers obtained the maximum adsorption amount of 6- O -α- d -maltosyl-β-cyclodextrin at 20.5 mg/g. In binding kinetic experiments, the adsorption reached saturation within 2 h with binding capacity of 72.8%. The experimental results showed that the adsorption capacity and selectivity of imprinted polymers were effective for the separation of 6- O -α- d -maltosyl-β-cyclodextrin, indicating that imprinted polymers could be used to isolate 6- O -α- d -maltosyl-β-cyclodextrin from a conversion mixture containing β-cyclodextrin and maltose. The results showed that the imprinted polymers prepared by this method were very promising for the selective separation of 6- O -α- d -maltosyl-β-cyclodextrin.
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EUROPEAN POLYMER JOURNAL
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2024
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IF 5.8
Jie Zhang,Siheng Zhang,Jianda Niu,Zhixian Dong,Jinbao Xu,Tingting Cui,Caihong Lei
With the increasing demands on healthy and environmental issues in modern society, green chemistry and atomic economics have become the consensus of researchers and manufacturers, forcing us to explore much simpler approaches to producing widely utilized biodegradable and biocompatible polyesters. In this context, 4-(hydroxymethyl) benzoic acid (4-HBA), an organic weak acid involving carboxyl and hydroxyl groups, was selected to proceed the ROP of various cyclic monomers, such as ε -caprolactone (CL), δ -valerolactone (VL), l-lactide (LA) and trimethylene carbonate (TMC), as catalyst and initiator in the same molecule (CINICAT) to give α -carboxyl- ω -hydroxyl polymers with controlled molar mass and narrow dispersity (around 1.15). MALDI-TOF, 2D-NMR and other characterizations were applied to confirm the structure of the produced polymers, while density of functional theory simulation ( DFT) calculation was carried out to study the structural influence of CINICAT on the polymerizations as well as the polymerization mechanism.
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Catalysts
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2024
·Vol. 14
·期 1
·70
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IF 3.8
Min Zhang,Hongwei Xiang,Xiaodong Wen
This investigation explores the synthesis of advanced catalysts for epoxidizing long-chain linear α-olefins, a pivotal process in the chemical industry for generating critical intermediates. Employing a hydrothermal technique, we developed four distinct catalysts (CS-1–4), methodically modulating the Ca/Sn ratio to elucidate its impact on the catalysts’ physicochemical properties. Our research uncovered that an escalated Ca/Sn ratio induces a morphological shift from octagonal to cubic structures, concomitant with a diminution in particle size and an enhancement in specific surface area. Significantly, the CS-3 catalyst outperformed others in 1-octene epoxidation, an efficacy attributed to its augmented surface alkalinity and proliferation of medium-strength alkaline sites, likely emanating from increased surface oxygen defects. Subsequent hydrogen reduction of CS-3 further amplified these oxygen defects, yielding a 10% uptick in catalytic activity. This correlation underscores the potential of oxygen defect manipulation in optimizing catalytic efficiency. Our findings contribute a novel perspective to the development of robust, high-performance catalysts for α-olefin epoxidation, seamlessly aligning with the principles of sustainable chemistry.Keywords:long-chain linear alpha-olefin;perovskite oxide;CaSnO3;oxygen vacancy;epoxidation
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JOURNAL OF SOLID STATE CHEMISTRY
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2024
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IF 3.2
Yin Xie,Zhuozheng Wang,Yan Cui,Liang Qiao,Kebin Chi,Dejun Shi,Yang Bai,Zhijie Wu,Shengbao He
2-Methoxyethanol (2-Me) is a promising solvent for large-area perovskite film preparation. Understanding the competing processes of α and δ-FAPbI 3 in 2-Me is crucial for advancing the application of 2-Me in FAPbI 3 film coating. In this study, FAPbI 3 microcrystals are fabricated by inverse temperature crystallization method at 100 °C, and are used as a platform to investigate the competing formation of α and δ-FAPbI 3 in 2-Me. Perovskite inks are analyzed using Raman, FTIR and DLS, and it is found that cluster ratio is closely related to the kinetic formation of δ-FAPbI 3 . The formation of α-FAPbI 3 can be significantly promoted when clusters are dissociated with additives (excess FAI or I 2 ). These findings provide valuable insights into the influence of precursor inks on perovskite phases.
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ANALYTICA CHIMICA ACTA
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2024
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IF 5.7
Yingying Zhong,Qing Wang,Zi-Jian Chen,Hongwu Wang,Suqing Zhao
Background In vitro screening strategies based on the inhibition of α-glucosidase (GAA) activity have been widely used for the discovery of potential antidiabetic drugs, but they still face some challenges, such as poor enzyme stability, non-reusability and narrow range of applicability. To overcome these limitations, an in vitro screening method based on GAA@GOx@Cu-MOF reactor was developed in our previous study. However, the method was still not satisfactory enough in terms of construction cost, pH stability, organic solvent resistance and reusability. Thence, there is still a great need for the development of in vitro screening methods with lower cost and wider applicability. Results A colorimetric sensing strategy based on GAA/(Au–Au/IrO 2 )@Cu(PABA) cascade catalytic reactor, which constructed through simultaneous encapsulating Au–Au/IrO 2 nanozyme with glucose oxidase-mimicking and peroxidase-mimicking activities and GAA in Cu(PABA) carrier with peroxidase-mimicking activity, was innovatively developed for in vitro screening of GAA inhibitors in this work. It was found that the reactor not only exhibited excellent thermal stability, pH stability, organic solvent resistance, room temperature storage stability, and reusability, but also possessed cascade catalytic performance, with approximately 12.36-fold increased catalytic activity compared to the free system (GAA + Au–Au/IrO 2 ). Moreover, the in vitro GAA inhibitors screening method based on this reactor demonstrated considerable anti-interference performance and detection sensitivity, with a detection limit of 4.79 nM for acarbose. Meanwhile, the method owned good reliability and accuracy, and has been successfully applied to the in vitro screening of oleanolic acid derivatives as potential GAA inhibitors. Significance This method not only more effectively solved the shortcomings of poor stability, narrow scope of application, and non-reusability of natural enzymes in the classical method compared with our previous work, but also broaden the application scope of Au–Au/IrO 2 nanozyme with glucose oxidase and peroxidase mimicking activities, and Cu(PABA) carrier with peroxidase mimicking activity, which was expected to be a new generation candidate method for GAA inhibitor screening.
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JOURNAL OF APPLIED POLYMER SCIENCE
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2024
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IF 2.7
Yucheng Zi,Dong Chen,Guochen Wang,Yuhong Ma,Wantai Yang
A simple strategy is proposed to offer styrene (St) copolymer with intrinsic and catalyst-free upcycling capability by incorporating α -methylstyrene (AMS) units into the copolymer poly(AMS -co- St) (PAS). Compared to polystyrene (PS), the PAS is more susceptible to depolymerizing into St and AMS monomers with higher yields at relatively lower temperature. The yield of liquid chemicals of PAS-4 (26.1 mol% AMS) is up to 93 wt% at 380°C, whereas that PS as control is 78 wt%. The reclaimed liquid chemicals of PAS-4 contain 58.4 wt% St and 37.7 wt% AMS, while the chemicals of PS contain 81.8 wt% St and 4.1 wt% AMS. The introduction of AMS units in PAS leads to a reduction in the liquid chemicals other than St and AMS monomers. The blends of PS and PAMS do not demonstrate the synergistic effect regarding facilitating the PS depolymerization. In addition, the properties of the new PASs prepared with the reclaimed monomers are comparable with those of the virgin PASs. This work proves the concept that recycling efficiency could be boosted by incorporating liable structural units into the copolymer chains and demonstrates a closed-loop of PS up-cycling.
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