RESEARCH ON CHEMICAL INTERMEDIATES
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2024
·Vol. 50
·期 6
·2897-2915
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IF 2.8
Liu Zengcheng,Wang Zhongchao,Wang Yanfei
The phosphinimide materials described in this paper were synthesized by polymerization precipitation. The properties of complexes coordinated with metal ions can be used as adsorbents for the adsorption of radioactive elements by using ligands such as imide and phosphorus groups. Then, the synthetic phosphinimide was characterized in detail by FT-IR, SEM, EDS and XPS, and its morphology and structural changes were studied. In addition, the effects of the material on the removal of uranium(VI) from aqueous solutions at different pH, sorbent doses, contact times, initial concentrations, and temperatures were studied. The experimental data shows that the adsorption process can fit the pseudo-second-order kinetic model well, which is in line with the Langmuir isotherm model. The thermodynamic study of adsorption shows that the adsorption process is a spontaneous endothermic process. In addition, at a temperature of 303.15 K and pH = 6, the maximum adsorption of uranium(VI) by phosphinimide in 25 min can reach 234.6 mg g −1 , and a removal rate of 97.75%.
研究领域:
化学
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环境科学
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DOI
高影响因子
Desalination and Water Treatment
·
2016
·
IF 1.272
Yan Xu,Jingjie Jin,Xianliang Li,Chaosheng Song,Hao Meng,Xia Zhang
A magnetic hybrid material (Fe3O4-embedded-MOF) consisting of a stable metal–organic framework HKUST-1 embedded with poly(N-vinyl-2-pyrrolidone) coated Fe3O4 microspheres was simply prepared under refluxing conditions for 4 h. The as-synthesized material was characterized using powder X-ray diffraction, scanning electron microscopy (SEM), vibrating sample magnetometry (VSM), energy dispersive spectroscopy (EDS) and N2 adsorption–desorption at 77 K. The hybrid material was studied for the adsorption of methylene blue from aqueous solution. The effects of dye concentration, adsorbent dose, and initial pH on the adsorption of methylene blue were measured, and from these experimental data, adsorption isotherms, kinetics, and thermodynamics were obtained. The results showed that a pseudo-second-order kinetic model and Langmuir isotherm (with R2 = 0.937) matched well for the adsorption of methylene blue onto Fe3O4-embedded-MOF. Thermodynamic parameters including free energy, enthalpy, and entropy of methylene blue adsorption were calculated, and the results showed that the adsorption of methylene blue were favorable on Fe3O4-embedded-MOF. The magnetic hybrid Fe3O4-embedded-MOF material features both magnetic separation characteristics as well as excellent adsorption performance for methylene blue in aqueous solution. The results of the present study demonstrate that Fe3O4-embedded-MOF is a promising adsorbent for the removal of dye from wastewater.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
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IF 4.058
Lixin Zhou,Shengdong Pan,Xiaohong Chen,Yonggang Zhao,Baobo Zou,Micong Jin
A novel core–shell covalently functionalized Fe 3 O 4 coated SiO 2 decorated multi-walled carbon nanotubes (Fe 3 O 4 @SiO 2 –MWCNTs) adsorbent was synthesized and characterized by scanning electron microscopy, transmission electron microscopy, Fourier Transform Infrared Spectrum (FTIR), Thermogravimetry, X-ray diffraction and magnetic measurements. The pentachlorophenol (PCP) adsorption effect factors of initial concentration, contact time, solution pH and temperature were investigated in detail. It was found the absorption capacity was strongly depended on pH, and the maximum adsorption value for PCP (96.4 mg/g) was obtained at pH 2.5. The equilibrium was attained within 30 min, and the adsorption kinetics was better described by pseudo-second-order kinetic model. The data pointed out excellent fit to Freundlich isotherm model. Thermodynamic parameters such as standard enthalpy (Δ H θ ), standard entropy (Δ S θ ) and standard free energy (Δ G θ ) showed that the adsorption of PCP onto Fe 3 O 4 @SiO 2 –MWCNTs was spontaneous, endothermic and random within the temperature range of 288–318 K. The results indicate that the Fe 3 O 4 @SiO 2 –MWCNTs adsorbent is a potential low-cost effective material for PCP removal from contaminated wastewater.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2016
·
IF 2.922
Yiying Zhang,Dongxiang Zhang,Kai Dong,Penghao Lv,Siping Pang,Chenghui Sun
The kinetics of the nitration reaction of 2,6,8,12-tetraacetyl-4,10-dinitro-2,4,6,8,10,12-hexaazaisowurtzitane (TADN) in HNO3–H2SO4 nitrating agent has been studied. The reaction network of the nitration reaction is constructed according to analysis of the experimental results. A kinetics model is introduced and the kinetics parameters are estimated by data fitting. Statistical analysis verifies that the kinetics model is in good agreement with the experimental data. Therefore, the reaction kinetics model can be applied to process analysis and scale-up of nitration of TADN to 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW).
研究领域:
化学动力学
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有机化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Hao Dong,Bo Wang,Xiandong Hao,Jinyu Wang,Zhiyong Xu,Wenbo Zhao
Seeking top-performing absorbents with excellent structural stability and renewability to realize efficient removal of H 2 S from natural gas is of great importance. Here, the H 2 S absorption thermodynamic and kinetic properties by a non-aqueous liquid binary blend of monoethanolamine (MEA) and ethylene glycol (EG) was systematically studied. The addition of solvent EG not only improves the thermal stability but also reduces the viscosity of the system especially after H 2 S absorption. The absorption mechanism was revealed by the combination of experimental characterization and Density Functional Theory (DFT) calculations, which show that the absorption process is a proton transfer reaction. In addition, a quasi-primary kinetic model was used to describe the absorption kinetic behavior, with rate constants increasing with temperature and pressure. Reaction equilibrium thermodynamic model (RETM) fitting thermodynamic results showed that the enthalpy (ΔH) and entropy (ΔS) of the interaction of the absorbent with H 2 S was −40.72 kJ/mol and −114.71 J/mol/K, respectively. Most importantly, the optimum absorption temperature was calculated to be 287.80 K and the optimum desorption temperature was 386.62 K. Moreover, the desulphurization rate was verified to increase with decreasing temperature and increasing H 2 S partial pressure. Five cycles of absorption-desorption experiments were conducted at 313.15 K for absorption and 373.15 K for desorption in order to verify the good reuse properties of the absorbent. Considering the excellent thermal stability, low viscosity after H 2 S absorption, acceptable absorption capacity as well as good reversibility, it is believed that the MEA/EG blend has a significant potential in the field of desulfurization.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2016
·
IF 2.76
Qiang Liu,Qinze Liu,Wei Ma,Weiliang Liu,Xiaoxia Cai,Jinshui Yao
Poly(catechol-diethylenetriamine- p -phenylenediamine) (PCEA1) and Poly(catechol-diethylenetriamine-melamine) (PCEA2), two kinds of similar chelating adsorbents with analogous structures, were used for the comparative study on Cr(VI) removal from aqueous solution. Many methods were employed to characterize these adsorbents, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectrometer (EDS). Batch experiments were carried out to investigate the adsorption performance of Cr(VI), such as pH value, adsorbent dosage, initial concentration, contact time and temperature. Furthermore, adsorption isotherm , intra-particle diffusion, kinetics and thermodynamics were studied completely and systematically. XPS technique confirmed that the reduction from toxic Cr(VI) to nontoxic Cr(III) existed in the adsorption process . After that, the removal of Cr(VI) in simulative wastewater caused by both adsorbents was nicely fitted with the Langmuir isotherm model and pseudo-second-order kinetic model . The maximum adsorption values of the PCEA1 and PCEA2 were 200 mg/g and 175.4 mg/g, respectively. The intra-particle diffusion study further demonstrated that adsorption processes all had two portions. The negative ΔG and positive ΔH indicated that the adsorption was spontaneous and endothermic. Tests on Cr(VI) removal indicated the potential applicability of the two adsorbents with a similar adsorption mechanism.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
Foods
·
2023
·Vol. 12
·期 12
·2424
·
IF 5.2
Yang Zhao,Xinrui Li,Shuo Guo,Jingwen Xu,Yan Cui,Mingzhu Zheng,Jingsheng Liu
Xylanases are the preferred enzymes for the extracting of oligosaccharides from wheat bran. However, free xylanases have poor stability and are difficult to reuse, which limit their industrial application. In the present study, we covalently immobilized free maleic anhydride-modified xylanase (FMA-XY) to improve its reusability and stability. The immobilized maleic anhydride-modified xylanase (IMA-XY) exhibited better stability compared with the free enzyme. After six repeated uses, 52.24% of the activity of the immobilized enzyme remained. The wheat bran oligosaccharides extracted using IMA-XY were mainly xylopentoses, xylohexoses, and xyloheptoses, which were the β-configurational units and α-configurational units of xylose. The oligosaccharides also exhibited good antioxidant properties. The results indicated that FMA-XY can easily be recycled and can remain stable after immobilization; therefore, it has good prospects for future industrial applications.Keywords:immobilized enzymes;kinetics;thermodynamics;wheat bran;oligosaccharide
研究领域:
生物化学
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酶学
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食品科学
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热力学
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产品关联
DOI
PubMed
高影响因子
PROGRESS IN REACTION KINETICS AND MECHANISM
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2017
·
IF 0.682
Jiao Jing Zhang,Wen Yi Wang,Guo Jian Wang,Cheng Kai,Hua Song,Lu Wang
A model natural gas consisting of hydrogen sulfide, nitrogen and oxygen mixture was used to simulate materials to test the performance of an amine-modified MCM-41 adsorbent prepared by the impregnation method. The adsorbent was characterised by X-ray diffraction analysis, Brunauer–Emmett–Teller analysis, Fourier-transform infrared spectroscopy, transmission electron microscopy and scanning electron microscopy. The results showed that more molecules are able to penetrate the pores following modification, resulting in rapid structural collapse, thus lowering the diffraction intensity. Although the capacity of amine-modified MCM-41 decreased the physical adsorption, chemisorption increased significantly. (3-Aminopropyl)trimethoxysilane/MCM-41 was found to exhibit a good performance for H2S desulfurisation. At 45 °C the breakthrough time was 186 min, the saturated sulfur capacity was 134.38 mg g−1 and the degree of desulfurisation was 54.19%. The adsorption isotherm and kinetics were investigated and the relevant parameters were obtained. The results showed that the adsorption isotherm could be well fitted by the Langmuir model and the maximum adsorption capacities increased with increase of temperature. The adsorption kinetics could be represented by the Bangham model, which suggested that chemical reaction seemed significant in the rate-controlling adsorption step. The adsorption process was spontaneous and exothermic.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2017
·
IF 0
Yunhong Yi,Junliang Lv,Nanjing Zhong,Gongqing Wu
The present study explored the ability of a novel spent chrysanthemum adsorbent prepared from acid acetaldehyde for the removal of Cu 2+ from an aqueous solution. The effect of various parameters, including solution pH, adsorbent dosage, contact time and temperature on adsorption of Cu 2+ were studied by batch experiments. According to the experimental results, the optimal pH range and optimum dosage were found to be 3.0–5.0 and 6.0 g/L, respectively. The adsorption amount at equilibrium decreased with the increase of temperature. Freudlich model provided better correlation for the adsorption of Cu 2+ by modified spent Chrysanthemum (MSC) (R = 0.99)and spent Chrysanthemum (SC)(R = 0.98). Adsorption capacity of MSC was 692 mg/g at 293 K, but it was 400 mg/g at 293 K for SC. The adsorption process on Cu 2+ proceeded rapidly and almost reached adsorption equilibrium within 20 min. The kinetics data of MSC were analyzed using the pseudo-first-order equations and pseudo-second-order equations. The pseudo-second-order equation fitted the experimental data very well (R = 0.99). The adsorption amount at equilibrium decreased with the increase of temperature. The thermodynamic parameters showed that the biosorption was exothermic and spontaneous. Experimental results showed that MSC could be used as an effective biosorbent for Cu 2+ removal from aqueous solutions.
研究领域:
环境科学
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生物学
✓ 已验证
DOI
Desalination and Water Treatment
·
2024
·
IF 1
Shanshan Chen,Kang Wen,Xiaoting Zhang,Ruize Zhang,Runping Han
Metal organic frameworks are attracting scientific interest in adsorption applications owing to their large surface area and controllable pore size or shape over both microporous and mesoporous domains. Based on this, an iron(III) trimesic acid MIL-100(Fe) was facilely synthesized by hydrothermal treatment and used as adsorbent to remove neutral red (NR) from aqueous solution. MIL-100(Fe) was characterized using X-ray diffraction, scanning electron microscopy and transform infrared spectroscopy. MIL-100(Fe) was studied in view of the adsorption isotherms, thermodynamics, kinetics, and regeneration of the adsorbent. The adsorption kinetics data of NR were found to be in agreement with pseudo-second-order model. Temkin model was observed to be more suitable than Freundlich and Langmuir models in describing the adsorption isotherm. The maximum adsorption quantity was 333 mg g –1 at 313 K from Langmuir model. Thermodynamic parameters indicated that the NR adsorption process was endothermic and spontaneous. The NR-loaded MIL-100(Fe) adsorbent was regenerated and reused using pH = 2, 75% ethanol. A single-stage batch design for NR adsorption onto MIL-100(Fe) was also presented based on Temkin isotherm model equation. Based on the findings, MIL-100(Fe) is a promising adsorbent for the removal of cationic dyes from solution and thus can be used in practical application.
研究领域:
环境科学
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材料科学
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化学工程
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Senliang Xi,Xiaojun Wang,Kudzaishe Caren Tome,Tonghuan Zhang,Zongying Han,Meng Gao,Shixue Zhou,Hao Yu
In this work, NaBH 4 +2MgH 2 doped by ZrF 4 was prepared by the ball-milling method. The structure and the morphology of different systems were characterized by X-ray diffraction and scanning electron microscopy. The thermodynamic properties of hydrogen release were determined by temperature-programmed desorption and differential scanning calorimetry . Hydrogen desorption kinetic properties and hydrogen content were investigated by pressure composition isothermal method. The main objective of this work was to study the relationship between the heat of hydrogen release and the quantity of hydrogen released by In-situ calorimetry measurement. The NaBH 4 +2MgH 2 +0.1ZrF 4 can release about 7.4 wt.% H 2 by two steps. Firstly, the heat of hydrogen release of the first and the second steps were lower by 480.82 J·g −1 and 430.8 J·g −1 than that of NaBH 4 +2MgH 2 , respectively. And the dehydrogenation enthalpy of NaBH 4 +2MgH 2 went from −243.81 kJ·mol −1 to −191.2 kJ·mol −1 . Secondly, the addition of ZrF 4 can improve the hydrogen release kinetic property of NaBH 4 +2MgH 2 , which can release 5 wt.% H 2 in 2.5 h at 385 °C under 0.01 MPa hydrogen pressure. Therefore, NaBH 4 +2MgH 2 +0.1ZrF 4 will be a potential candidate as a fuel cell hydrogen supply system.
研究领域:
材料科学
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能源科学
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DOI
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Caiyun Liu,Fujing Zheng,Huiying Li,Mario Prejanò,Guojie Jin,Yongsheng Tao,Yunkui Li
This study investigated molecular interactions between benzoic acids (gallic acid/protocatechuic acid) and acetate esters using thermodynamics and quantum mechanics, as well as the effects of benzoic acids on acetate esters release and perception in simplified and real wine systems, respectively. Results showed spontaneous binding (ΔG < 0) between benzoic acids and acetate esters (ethyl octanoate > ethyl hexanoate > isoamyl acetate > ethyl butyrate > ethyl acetate), with gallic acid exhibiting stronger affinities. The OH of benzoic acids and COO of acetate esters were the key groups, driven synergistically by hydrogen bonding, dispersion interactions, and hydrophobic effects, while electrostatic contributions dominated interaction energies (43–60 %). Benzoic acids significantly reduced acetate esters release, showing structure- and concentration-dependent trends. Aroma profile and perception revealed benzoic acids promoted formation and retention of fermentation aroma, enhancing flavor and fruitiness. These findings provided mechanistic insights for modulating wine aroma through benzoic acid- acetate ester interactions.
研究领域:
食品科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）