EUROPEAN POLYMER JOURNAL
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2021
·
IF 4.598
Zhanfeng He,Qiang Chen,Yuanyuan Luo,Yuan He,Yinshan Zhang,Tong Liu,Wenyuan Xu,Jiali Zhang,Yongxin Liu,Leyan Xiong,Shaohui Wang,Zanru Guo
Adsorbent with high and recyclable adsorption for pollutants without secondary pollution is one of great potential in water treatment. Here, degradable CO 2 -responsive microgels with big size and wrinkled porous structure were prepared. The microgels underwent reversible volume phase changes upon alternative stimulus of CO 2 and N 2 , and thereby exhibited a switchable, selective, and recyclable adsorption for anionic dyes and metalloids (Cr(VI) and As(V)). The adsorption performance was improved due to the wrinkled porous structure, and the maximum adsorption capacity was up to 1537 mg g −1 for metanil yellow (MY). The competitive adsorption in binary and ternary system revealed that the affinity was in the order of MY > ponceau S (PS) > Cr(VI). Besides, the adsorbates could be desorbed by heating or treating with solution of pH 12. Microgels regenerated with CO 2 trigger exhibited high adsorption ability after ten consecutive recycling trials, and could be applied to fixed-bed adsorption/desorption system. Moreover, microgels could be degraded. Thus, this kind of degradable microgels have potential applications in the treatment of complex industrial wastewaters and avoid the additional pollution caused by the accumulation of waste adsorbents.
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ENZYME AND MICROBIAL TECHNOLOGY
·
2021
·
IF 3.493
Xiaoting Dong,Pengli Xue,Xian Ma,Yifan Bai,Penghui Shi,Liujiao Bian
The recognition and interaction of FEZ-1 from Legionella (FEZ-1) with penicillin V(PV) and cefoxitin(CFX) were investigated using fluorescence spectra in combination with molecular dynamics simulation (MD). The results revealed that the CFX bind with FEZ-1 in stronger interaction and induced larger conformational change than PV, despite all being forced by the electrostatic interaction and along with the changing in an environment of amino acid residues as well as the polypeptide skeleton inside the FEZ-1. Moreover, only the loop1, loop2, and N-terminal were observed locating near the binding pocket of FEZ-1, consisting of a flexible “gate-like” zone with better adaptability that controlled the entrance of antibiotic into the pocket by allowing the newly introduced antibiotic to match the pocket better through the conformational changes of these three substructures in the binding procedure. The current study may provide some valuable information on the antibiotic hydrolytic process by metallo-beta-lactamase and thus the references for the development of new antibiotics for super bacteria.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Yi Yu,Fanfan Li,Xinghao Han,Shanghai Long,Shishuai Shi,Li Xu,Guoji Liu
2-Naphthaldehyde is industrially produced from 2-naphthalene nitrile and 2-naphthoyl chloride in acid. Greener gas-solid catalytic oxidation of 2-methylnaphthalene to 2-naphthaldehyde has rarely been investigated. In this study, the preparation of 2-naphthaldehyde over V/TiO2 catalysts doped with 13 metal promoters was explored and the V-Cu(1)/TiO2 catalyst showed excellent performance with 63.37% 2-methylnaphthalene conversion and 70.09% 2-naphthaldehyde selectivity at 400 °C, gas hourly space velocity (GHSV) of 10 000 h–1, and feed flow rate of 3.87 × 10–4 mol·h–1, giving the highest turnover frequency (TOF) value of 17.05 × 10–6 s–1. We have consequently studied the effect of Cu doping on the physicochemical properties of the V/TiO2 catalyst and found that structural changes are not the main reason to improve the catalytic performance. Increased vacancies and oxygen mobility accelerate the formation of nucleophilic oxygen from electrophilic oxygen, which are the key factors to improve 2-NA selectivity. The synergy between V, Cu, and O through the V–O–Cu bridging bond also improves the weak acid ratio, redox ability, and the reactivity of active sites (bridging and terminal oxygen). X-ray photoelectron spectroscopy (XPS), in situ diffuse-reflectance infrared Fourier transform (DRIFT) spectroscopy, and density-functional theory (DFT) calculations have proved that this reaction obeys the Mars–van Krevelen mechanism and involves a reduction process of V5+ and Cu2+ during oxidation.
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Journal of Physical Chemistry C
·
2020
·
IF 4.189
Yefeng Feng,Furong Zhou,Maolin Bo,Yuehao Huang,Qihuang Deng,Cheng Peng
High dielectric constant and breakdown strength are crucial for high-energy-density polymer/ceramic composites. Anatase-TiO2 with low dielectric constant and V2C MXene with high work function are not satisfactory fillers. In the present work, V2C–TiO2 hybrid filler was in situ synthesized, followed by fabricating poly(vinylidene fluoride) (PVDF)/V2C–TiO2 composites via solution cast. Compared with PVDF/TiO2 and PVDF/V2C composites, PVDF/V2C–TiO2 composites have an improved high dielectric constant, depressed low dielectric loss, and maintained high breakdown strength. High overall electric traits are ascribed to the synergy of conductive V2C and semiconductive TiO2. Outer and inner surfaces of V2C were ornament-combined by anatase-TiO2 particles having surface point defects as electron traps, contributing to low interface leakage conduction. Through density functional theory (DFT) calculations, nontypical V–F–Ti-bonding-induced dipole enhancement and Fermi-level (EF) overlapping-induced high electron localization mechanisms improve the dielectric response. Ternary composite with 10 wt % hybrid filler exhibits a dielectric constant of ∼99, a dielectric loss of ∼0.24 at 1 kHz, and a breakdown strength of ∼189 MV/m. This work might enable large-scale preparation of promising polymer/MXene composite dielectrics.
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ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Shuchang Wang,Yang Deng,Binbin Shao,Jiahui Zhu,Zixin Hu,Xiaohong Guan
For the first time, this study showed that the apparent second-order rate constants (kapp) of six selected emerging organic contaminants (EOCs) oxidation by Fe(VI) increased, remained constant, or declined with time, depending on [EOC]0/[Fe(VI)]0, pH, and EOCs species. Employing excess caffeine as the quenching reagent for Fe(V) and Fe(IV), it was found that Fe(V)/Fe(IV) contributed to 20–30% of phenol and bisphenol F degradation by Fe(VI), and the contributions of Fe(V)/Fe(IV) remained nearly constant with time under all the tested conditions. However, the contributions of Fe(V)/Fe(IV) accounted for over 50% during the oxidation of sulfamethoxazole, bisphenol S, and iohexol by Fe(VI), and the variation trends of kapp of their degradation by Fe(VI) with time displayed three different patterns, which coincided with those of the contributions of Fe(V)/Fe(IV) to their decomposition with time. Results of the quenching experiments were validated by simulating the oxidation kinetic data of methyl phenyl sulfoxide by Fe(VI), which revealed that the variation trends of kapp with time were significantly determined by the change in the molar ratio of Fe(V) to Fe(VI) with time, highlighting the key role of Fe(V) in the oxidative process. This study provides comprehensive and insightful information on the roles of Fe(V)/Fe(IV) during EOC oxidation by Fe(VI).
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Environmental Technology & Innovation
·
2021
·
IF 5.263
Changjin Jiang,Rongtao Lyu,Ting Zhang,Zhaoguang Yang
A facile hydrothermal synthetic method was employed for the preparation of Fe 3+ coordinated to amino-functionalized spherical mesoporous silica (Fe–NH 2 –SMS), aimed at the rapid and efficient removal of As(V) from water. The morphology, structure and properties of the adsorbent were characterized via SEM, EDS, N 2 adsorption–desorption, FT-IR, zeta-potential and XPS. Fe–NH 2 –SMS exhibited a high performance for As(V) removal with a very fast adsorption rate (reaching equilibrium within 1 min). As(V) adsorption on Fe–NH 2 –SMS was better fitted to the Langmuir isotherm model ( R 2 = 0 .988). The maximum adsorption capacity was 43.34 mg g –1 As(V) at 25 °C. The optimum pH for As(V) adsorption was in the range of 5–10. The individual presence of SO 4 2– , SO 3 2– , HPO 4 2– and CO 3 2– had a negative effect on As(V) adsorption. The removal of As(V) via Fe–NH 2 –SMS in real water samples remained above 95% with an increasing adsorbent dosage up to 1.6 g L –1 . Reusability studies indicated that the removal of As(V) was still up to 76% after five adsorption–desorption cycles. Electrostatic attraction and inner-sphere complexation between As(V) and functional groups (–NH 2
⋅
⋅
⋅ Fe 3+ ) were identified as the adsorption mechanisms of As(V). The prepared adsorbent can be considered a promising adsorbent for the rapid adsorption of As(V) from water.
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PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 26
·17942-17951
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IF 3.906
Muge Niu,Yucui Hou,Weize Wu,Shuhang Ren,Ru Yang
Vanadium(V)-catalyzed aerobic oxidation in aqueous solution shows high selectivity in the field of C–C bond cleavage of carbohydrates for chemicals with less carbon atoms. However, the pathway of C–C bond cleavage from carbohydrates and the conversion mechanism are unclear. In this work, we studied the pathway and the mechanism of D-glucose oxidation to formic acid (FA) in NaVO3–H2SO4 aqueous solution using isotope-labeled glucoses as substrates. D-Glucose is first transformed to FA and D-arabinose via C1–C2 bond cleavage. D-Arabinose undergoes similar C1–C2 bond cleavage to form FA and the corresponding D-erythrose, which can be further degraded by C1–C2 bond cleavage. Dimerization and aldol condensation between carbohydrates can also proceed to make the reaction a much more complicated mixture. However, the fundamental reaction, C1–C2 bond cleavage, can drive all the intermediates to form the common product FA. Based on the detected intermediates, isotope-labelling experiments, the kinetic isotope effect study and kinetic analysis, this mechanism is proposed. D-Glucose first reacts with a vanadium(V) species to form a five-membered-ring complex. Then, electron transfer occurs and the C1–C2 bond weakens, followed by C1–C2 bond cleavage (with no C–H bond cleavage), to generate the H3COO˙–vanadium(IV) complex and D-arabinose. FA is generated from H3COO˙ that is oxidized by another vanadium(V) species. The reduced vanadium species is oxidized by O2 to regenerate to its oxidation state. This finding will provide a deeper insight into the process of C–C bond cleavage of carbohydrates for chemical synthesis and provide guidance for screening and synthesizing new highly-efficient catalyst systems for FA production.
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POLYMER
·
2015
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IF 3.562
Huanhuan Liu,Xiao Jiang,Rongjian Bian,Min Tong,Dandan Tang,Xiangdong Zhou,Youliang Zhao
Controlled synthesis of A 2m B 2n -type (m ≈ n ≈ 8) starlike copolymers comprising an oligomeric poly(styrene- co -maleimide) core and two types of V-shaped arms individually generated by ATRP and ROP was described. Multistep syntheses involving RAFT copolymerization , end group removal, ATRP of vinyl monomers such as styrene (St), methoxyethyl methacrylate (MEMA) and tert -butyl acrylate ( t BA), and ROP of ε -caprolactone (CL) were used to construct the target miktoarm stars with controlled molecular weight and relatively low polydispersity (PDI = 1.07–1.22). The resultant star copolymers had high bromide functionality and uniform chain length of ATRP-generated arms, evident from chain extension polymerization and cleavage of arms. Meanwhile, a pH-responsive (PAA) 2m (PCL) 2n star was also obtained by selective hydrolysis. The synthetic strategy via combination of RAFT copolymerization and “core first” approach is versatile in constructing various A 2m B 2n stars, and this study further paves way for facile synthesis and properties of new types of miktoarm stars.
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TALANTA
·
2013
·
IF 3.498
Shengping Wen,Xiashi Zhu
A simple, sensitive and efficient method of ultrasound-assisted emulsification of solidified floating organic drop microextraction (USE-SFODME) coupled to electrothermal atomic absorption spectrometry for the speciation of antimony at different oxidation state Sb(III)/Sb(V) in environmental samples was established. In this method, the hydrophobic complex of Sb(III) with sodium diethyldithiocarbamate (DDTC) is extracted by 1-undecanol at pH 9.0, while Sb(V) remains in aqueous phase. Sb(V) content can be calculated by subtracting Sb(III) from the total antimony after reducing Sb(V) to Sb(III) by l -cysteine. Various factors affecting USE-SFODME including pH, extraction solvent and its volume, concentration of DDTC, sonication time, and extraction temperature were investigated. Under the optimized conditions, the calibration curve was linear in the range from 0.05 to 10.0 ng mL −1 , with the limit of detection (3 σ ) 9.89 ng L −1 for Sb(III). The relative standard deviation for Sb(III) was 4.5% ( n =9, c =1.0 ng mL −1 ). This method was validated against the certified reference materials (GSB 07-1376-2001, GBW07441), and applied to the speciation of antimony in environmental samples (soil and water samples) with satisfactory results.
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Analytical Methods
·
2017
·Vol. 9
·期 30
·4471-4475
·
IF 1.9
L. F. Tian,D. S. Zou,Y. C. Dai,L. L. Wang,W. Gao
Quantification of chromium in V–Cr–Ti ternary alloys, used as candidate structural materials for fusion reactors, is essential in view of its significant effect on the properties of these vanadium-based alloys. Various methods have already been used for the determination of chromium in common alloys, but most of these methods are based on complicated and expensive instruments or suffer from the serious matrix interference of vanadium. In this study, a simple, rapid and accurate spectrophotometric method was developed for the determination of chromium in V–Cr–Ti alloys without any prior separation and chromogenic agent. The alloy samples were dissolved in diluted sulphuric acid and concentrated nitric acid, and chromium was oxidized with persulphate in the presence of Ag(I) ions as a catalyst. After alkalization of the solution with sodium hydrate, greenish-yellow coloured chromate (CrO42−) ions were formed in the alkaline solution and had a maximum absorption peak at 374 nm. Beer's law was obeyed in the range of 0.15–12.0 μg mL−1 Cr(VI) at 374 nm and the molar absorptivity was 4.8 × 103 L mol−1 cm−1. All the variables were studied in order to optimize the analytical conditions. Vanadium and titanium seriously interfered with the determination of Cr(VI) and their interference can be eliminated by addition of ammonium tartrate. The proposed method is simple, fast, accurate and of low cost, and has been satisfactorily used for the determination of chromium in V–Cr–Ti alloys. The results are in good agreement with data given by inductively coupled plasma optical emission spectrometry (ICP-OES) and the relative standard deviation is found to be lower than 0.4%.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Alfin Kurniawan,Jian Qiang Zhong,Ze Zhen Wang,Chun Hui Zhou
Allyl alcohol, an industrially valuable intermediate in organic synthesis, is conventionally produced through selective hydrogenation of acrolein and hydrolysis of chloropropene. However, these processes currently face challenges due to the unsustainability of fossil feedstocks. A more sustainable production of allyl alcohol from renewable feedstock (i.e., glycerol) has been demonstrated through gas-phase catalytic reaction over metal oxide catalysts with and without external H2. Improved understanding of the reaction mechanism of glycerol to allyl alcohol conversion is an important effort to rationally design more efficient catalysts. In this work, we investigate gas-phase conversion of glycerol to allyl alcohol through consecutive dehydration and hydrogen transfer reactions over Mo–V oxides supported on acid-modified montmorillonite (HMMT). The use of HMMT as a support enables the well dispersion of metal oxide particles with nominal loadings up to 5 wt % on the catalyst surface while the acidic sites facilitate dehydration of glycerol to acrolein with ∼74% selectivity. By modulating the nominal total Mo+V loading, Mo–V/HMMT catalyst with a 10 wt % metal loading afforded allyl alcohol in 22% yield at 320 °C and ambient pressure. X-ray photoelectron spectroscopic analysis of this bifunctional catalyst in the as-prepared and post-catalysis (spent) states showed changes in the surface Mo(VI)═O species and V4+/V5+ redox ratio; the latter was found to decrease due to the involvement of lower valence V4+ species in the hydrogen transfer reaction of acrolein. Meanwhile, the amount of surface Mo(VI)═O species with weak electronic metal–support interaction decreases after the reaction. Catalytic tests using an aqueous acrolein feed solution suggested the role of water as a hydride donor in transfer hydrogenation of this unsaturated aldehyde to allyl alcohol, while the addition of alcohol-containing compounds, such as 2-propanol and 1,2-propanediol leads to lower allyl alcohol selectivity with time on stream. The results presented here could guide the development of improved supported Mo−V oxide catalysts and reaction systems for efficient gas-phase glycerol conversion to allyl alcohol.
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Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Mengistu Tadesse Mosisa,Pengkun Zhang,Zhengjie Su,Binghong Wu,Longyan Chen,Yiqiang Liao,Ambar Farooq,Dongfang Lu,Adugna Boke Abdeta,Dong-Hau Kuo,Jinguo Lin,Xiaoyun Chen
Organic pollutants in industrial and agricultural wastewater can be dangerous to both human health and the environment. Therefore, it is important to develop methods for continuous catalytic reduction of these pollutants under dark conditions as sunlight has geographical and temporal limitations due to different regions, weather conditions, and Earth's rotation . This could have significant implications for practical wastewater treatment . In this study, we successfully synthesized bimetallic vanadium bismuth oxy-sulfo bromide (labeled as VBiOSBr) catalysts using a simple precipitation method by doping V/S into BiOBr to from (Bi,V)(S,O)Br. The morphology, structure, optical absorption properties, electron-hole recombination rate, and reduction performance of the catalysts were examined in detail. The catalyst displayed a tetragonal phase with an energy band gap and specific surface area of approximately 1.93 eV and 22.1 m 2 /g, respectively. The 1-VBiOSBr catalyst prepared with n (V): n (Bi): n (KBr): n (C 2 H 5 NS) = 1: 1: 1: 1 had the best catalytic activity . Within just 14 min, this catalyst removed 98.7% and 96.96% of 4-NP and Cr 6+ , respectively. The VBiOSBr catalyst remained stable and efficient even after the seventh run, still achieving a removal rate of 94.7%. The study proposed a possible mechanism for 4-NP and Cr 6+ reduction activity. The catalyst's simple manufacturing process and its ability to reduce pollutants under dark conditions make it a promising system for practical application in the continuous removal of organic pollutants. So, the VBiOSBr bimetallic catalyst has great potential as a candidate for wastewater treatment technologies.
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