International Journal of Greenhouse Gas Control
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2015
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IF 3.946
Xia Wang,Qingjie Guo,Jun Zhao,Linlin Chen
A CO 2 sorbent was prepared by immobilizing a mixture of tetraethylenepentamine (TEPA) and 2-amino-2-methyl- l -propanol (AMP) onto MCM-41. The prepared composites were characterized by N 2 adsorption–desorption, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) techniques. CO 2 adsorption–desorption experiments were conducted in a self-assembled fixed bed reactor under the simulated flue gas component of 15 vol.% CO 2 /85 vol.% N 2 . The promoting effects of AMP on the adsorption performance and amine efficiency of TEPA modified MCM-41 were studied. In addition, the effects of the adsorption temperature and the feed flow rate on the CO 2 adsorption process were investigated. Further, the regenerability of the sorbent was studied by performing fifteen adsorption–desorption cycles over the temperature range of 70 °C (adsorption) to 100 °C (desorption). Among the prepared sorbents, MCM-41 modified with 30 wt.% TEPA and 30 wt.% AMP (MCM-41-TEPA30%-AMP30%) showed rapid adsorption kinetics and the maximum CO 2 adsorption capacity of 3.01 mmol-CO 2 /g-sorbent at 70 °C. Moreover, the MCM-41-TEPA30%-AMP30% sorbent exhibited good regenerability and thermal stability. The results demonstrate that the MCM-41-TEPA30%-AMP30% sorbent is a promising CO 2 sorbent.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2017
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IF 2.843
Peng Liu,Ni Yuan,Wei Xiong,Hanyu Wu,Duoqiang Pan,Wangsuo Wu
β-Zeolite was synthesized and modified with ethylenediamine (EDA). The synthesized materials were characterized and used for the removal of nickel(II) from aqueous solutions. The influences of the pH, contact time, and temperature on nickel(II) adsorption onto synthesized β-zeolite and β-zeolite modified with ethylenediamine (β-zeolite–EDA) were studied by a batch technique, and X-ray photoelectron spectroscopy was employed to analyze the experimental data and identify the formation of coordination bonds between the adsorbents and nickel(II). The dynamic process showed that the adsorption of nickel(II) onto β-zeolite and β-zeolite–EDA matched the pseudo-second-order kinetics model, and the adsorption of nickel(II) was significantly dependent on the pH values. Through simulation of the adsorption isotherms by the Langmuir, Freundlich, and Dubinin–Radushkevich models, it could be seen that the adsorption patterns of nickel(II) onto β-zeolite and β-zeolite–EDA were mainly controlled by surface complexation and the adsorption processes were endothermic and spontaneous. The modification of β-zeolite–EDA improved the adsorption capacity of nickel(II) significantly; this shows a novel material for the removal of nickel(II) from the water environment for industrialized application.
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
CHEMICAL ENGINEERING SCIENCE
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2024
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IF 4.1
Yiting Yang,Yulu Liu,Shengyu Liu,Yong Zhao,Qiang Zhang,Lin Su,Ziyi Chen,Mengting Zhao
Sustainable feedstocks and low-cost precursors are crucial for the development of adsorbents for CO 2 capture. In this study, three different amine-modified adsorbents were synthesized using sustainable green feedstock, coconut shells, and physical impregnation of DETA, TETA, and TEPA at different loadings (30%, 30%, and 10%, respectively). Their potential as alternative adsorbents for CO 2 capture was investigated. Compared to the original activated carbon, all three amine-modified adsorbents showed improved CO 2 uptake, with the DETA-modified adsorbent showing the highest CO 2 adsorption capacity. The influence of carbon chain length and amine types on CO 2 capture was studied in detail. Density functional theory (DFT) calculations were performed to study the CO 2 adsorption on the bare activated carbon and the amine-modified adsorbents. The results showed that shorter carbon chains and primary amines could improve the CO 2 adsorption performance of the adsorbents regardless of whether the organic amines were dehydrogenated.
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
Journal of the Taiwan Institute of Chemical Engineers
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2018
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IF 3.849
Yafei Guo,Chang Tan,Peng Wang,Jian Sun,Junjie Yan,Weiling Li,Chuanwen Zhao,Ping Lu
Coal and biomass fly ash was impregnated with tetraethylenepentamine (TEPA) to prepare solid CO 2 sorbent. Experimental CO 2 adsorption capacities of the sorbent in fixed-bed column were fitted to several kinetic equations. The modified Avrami fractional kinetic model could accurately predict the CO 2 adsorption kinetic behaviors of the sorbent under different conditions. CO 2 adsorption rate increases with the increase in temperature, initial CO 2 concentration and gas flow rate, as a result of the decreased CO 2 diffusion resistance. A mathematical model was proposed and demonstrated to well predict the CO 2 adsorption breakthrough curves in the fixed-bed column. Effects of temperature, initial CO 2 concentration and gas flow rate on the mass transfer kinetic behaviors of the desired sorbent were investigated. The positive effect of these factors on promoting the overall mass transfer coefficient and the internal mass transfer coefficient is not significant. The external mass transfer coefficient will be remarkably reinforced with the increase in these operating parameters, due to the change in viscosity and density of the gas phase and the reduced external mass transfer resistance. Internal mass transfer process is determined as the rate-limiting step for CO 2 adsorption. The results will lay the groundwork for future scale-up application of the sorbent in post-combustion CO 2 capture.
研究领域:
环境科学
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化学工程
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能源工程
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大气污染控制
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碳捕集与封存
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Gang Wang,Zengxi Li,Liu Fan,Chunshan Li,Suojiang Zhang
S ec -amines catalyzed two-step Mannich reaction for preparation of methacrolein from propionaldehyde and formaldehyde was more attractive than the C 4 selective oxidation route. Herein, a novel continuous fixed-bed process was developed for direct preparation of methacrolein from above stocks with catalysis of sec -amine grafted D301 resin. The effect of resin, sec -amine structure and grafting percentage on catalytic performance of the modified resin were detailed investigated and demonstrated by using FT-IR, TG-DTA, titration and solid-state NMR characterization methods before the optimal conditions were obtained. The grafting percentage of amine with abundant sec -amino groups onto D301 resin could reach 93.7% at optimal condition. With this new strategy, the yield and selectivity of methacrolein could attain 40.2% and 99.3%. In addition, the Mannich reaction step with activation energy of 66.3 kJ/mol was determined as the rate-controlling step through mechanism-based kinetic calculation.
研究领域:
有机化学
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催化化学
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DOI
高影响因子
ENERGY & FUELS
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2012
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IF 2.721
Qing Ye,Jianqing Jiang,Chunxia Wang,Yamin Liu,Hua Pan,Yao Shi
A solid amine adsorbent for CO2 was developed by carbon nanotubes (CNTs) impregnated with tetraethylenepentamine (TEPA). The adsorption behavior toward CO2 (2.0 vol %) was investigated in a fixed-bed column. After modification, the adsorption capacity of CNTs–TEPA reached 2.97 mmol g–1 at 298 K. Rising temperatures from 283 to 313 K enhanced the CO2 adsorption capacity. The maximum adsorption capacity was approximately 3.56 mmol g–1 at 313 K. The adsorption capacity was also influenced by moisture and reached as high as 3.87 mmol g–1 (2.0% H2O). In comparison to many other types of modified carbon or silica adsorbents in the literature, CNTs–TEPA had a higher adsorption capacity at the same temperature. The adsorption capacity for CO2 remained almost the same after cyclic regeneration experiments. A deactivation model, capable of describing the uptake of CO2, was applied under various conditions. In all cases, the experimental data agreed with the predicted breakthrough model.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2021
·Vol. 56
·期 14
·8528-8543
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IF 4.22
Wang Junchao,Zhang Zetian,Xie Taoling,Sun Liying,Yang Kaifeng,Liu Yang,Li Zhengjun
Polyhedral oligomeric silsesquioxanes (POSSs) can be utilized to prepare nanocomposites to improve their physical and mechanical properties significantly by physical interaction and chemical cross-linking. The purpose of this work is to prepare a kind of water-dispersive POSS containing multiple epoxy groups and then use it to prepare gelatin/POSS nanocomposites to enhance their thermal and mechanical properties. Accordingly, 3-glycidyloxypropyl-POSS (G-POSS) was synthesized by a complete hydrolysis and condensation method. Then, G-POSS was modified with polyetheramine to obtain a derivative material of POSS, denoted as P-G-POSS, which possess better water dispersion and flexibility. Importantly, the chemical structure of both G-POSS and P-G-POSS was confirmed by FT-IR, NMR, XPS and EDS analyses. Subsequently, POSS/gelatin nanocomposites were prepared in accordance with 1:1, 2:1 and 3:1 of epoxy/amino mole ratios in alkaline aqueous medium. The microscope porous structure, thermal stability, mechanical properties, along with water absorption of the composites containing various contents of P-G-POSS, were emphatically studied and discussed. The results indicated that composites possessed the maximum denaturation temperature up to 80.1 °C, as well as the increased initial decomposition temperature and residual mass at 700 °C, and particularly improved mechanical properties after incorporation of P-G-POSS into gelatin matrix. The reason is likely that the cross-linking reaction of epoxy groups in P-G-POSS with amino groups in gelatin macromolecules, along with hydrogen bonding, played an important role in the as-prepared gelatin/POSS composites. This study would be helpful to promote the application of POSSs in bone tissue regeneration and leather cleaner production.
研究领域:
材料科学
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生物医学工程
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DOI
高影响因子
Materials Research Express
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2022
·Vol. 9
·期 4
·045304
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IF 2.025
Xiangyu Wang,Jing Zhou,Rui Meng,Yu Zhao,Weihong Guo
This paper investigates the modification of dopamine (IDA) and uses it as a crosslinking agent to enhance the mechanical strength and hydrophobicity of room-temperature-vulcanized (RTV) silicone rubber. IDA was successfully synthesized with dopamine and 3-isocyanatopropyltriethoxysilane. The structure of IDA was verified by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. IDA was introduced into the hydroxyl-terminated polydimethylsiloxane (PDMS) system to prepare RTV silicone rubber, and dibutyltin dilaurate (DBTDL) was used as the catalyst. A combination of the scanning electron microscope, thermal gravimetric analysis, universal testing machine, and contact angle was used to analyze the morphology and properties of RTV silicone rubber. The results demonstrated that the addition of IDA significantly enhanced the thermal stability and mechanical strength of RTV silicone rubber. The mechanical strength of the novel RTV silicone rubber increased by 221%. Moreover, the IDA modified RTV silicone rubber had better hydrophobicity as compared to the PDMS polymer prepared with the traditional crosslinking agent.
研究领域:
材料科学
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有机化学
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产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
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2024
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IF 4.5
Lishuang Yang,Jiayue Wang,Ruili Li,Yujie Gao,Huashan Wang
A novel UV-curable 3D printing resin was synthesized by combining diglycidyl ether of bisphenol A (DGEBA) and acrylamide (AAM) to create a UV-curable acrylamide-modified epoxy resin prepolymer. This prepolymer was then uniformly mixed with the photoinitiator TPO and the reactive diluent hydroxyethyl methacrylate (HEMA). By adjusting the prepolymer content, UV-curable 3D printing resins were formulated with prepolymer concentrations of 30 wt%, 40 wt%, and 50 wt%, respectively. Infrared spectroscopy and nuclear magnetic resonance studies indicated that the amino groups in acrylamide reacted with the epoxy groups. When the prepolymer was added at concentrations of 30 wt% and 40 wt%, the viscosity met the requirements for UV-curable 3D printing. Upon completion of curing, these three distinct resins exhibited high mechanical strength, with tensile strength reaching up to 59.42 MPa and flexural strength peaking at 72.25 MPa. The elongation at break ranged from 2.60 % to 4.91 %. Scanning electron microscopy was used to examine the UV-cured 3D printed samples, and comparison with the design files revealed that the printed samples exhibited excellent dimensional stability. The study results indicated that this novel UV-curable epoxy vinyl resin formulation possessed excellent mechanical properties, suitable curing characteristics, and high resolution, making it a highly promising prepolymer for UV-curable 3D printing.
研究领域:
材料科学
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化学工程
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3D打印技术
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DOI
高影响因子
Desalination and Water Treatment
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2024
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IF 1
Yanzhuo Zhang,Haiqin Zhang,Jing Zhao,Xiaozhuan Zhang
There is a growing problem of excessive fluoride ion (F – ) in mine water in western China and it is urgent to identify appropriate treatment strategies. In this work, we tested polyethylenimine-modified diatomite for adsorption of low concentration F – from aqueous solution. Fourier-transform infrared spectroscopy analysis suggested amino group (–NH 2 ) may be the main functional group promoting adsorption. Scanning electron microscopy and Brunauer–Emmett–Teller–Barrett– Joyner–Halenda analysis showed that the modified diatomite surface became smooth and the specific surface area decreased slightly with modification. The optimal pH, temperature, and dosage of polyethylenimine modified diatomite (PEI/DT) were determined as 2.0°C, 5°C, and 0.2 g/L, respectively. The whole adsorption process can be completed in 20–30 min. The adsorption data were better fit to the Langmuir model (average R 2 = 0.9962) to describe the adsorption process than the Freundlich model (average R 2 = 0.9413). The adsorption efficiency of F – by PEI/DT was highest at 5°C, with a maximum saturated adsorption capacity ( q max ) of 28.62 mg/g. The pseudo-second-order kinetic model (average R 2 = 0.9992) is more suitable to describe the overall adsorption process and the pseudo-first-order kinetic model (average R 2 = 0.7318) can only describe the initial stage of adsorption. Thermodynamic parameters confirm that the adsorption process is a spontaneous exothermic process. Overall, the results show that the prepared PEI/DT can potentially be used as an adsorbent to remove F – from mine water.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
Materials Today Communications
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2023
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IF 3.8
Jinmin Zhao,Juanli Chen,Liting He,Youhua Cao,Chengqiang Peng,Jing Fang,Zhongyu Duan,Hao Li
Polyvinylidene fluoride membranes (PVDFMs) are frequently used in oil-water separation due to their stable properties, high porosity, and modification easily. However, the pollution, low separation efficiency, and low recovery rate of PVDFMs have limited the oil sewage treatment. This work is based on dopamine-modified PVDFMs, which prepared hydrophilic separation membranes by attaching hydroxymethylated lignin (HAL) to PVDFMs. Lignin was hydroxymethylated to improve its hydrophilicity. Additionally, HAL was assembled on the surface of PVDFMs with the effect of dopamine (DA) and 3-aminopropyltriethoxysilane (KH550). The effect of the ratio of DA and KH550 (D: K) and HAL concentration on the hydrophilic effect was explored. The modified membranes exhibited considerable separation efficiency (>99 %) for several kinds of oil-water emulsions and could be recycled multiple times. This green modification method using lignin provides an environmentally friendly solution for modifying PVDFMs.
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
ChemCatChem
·
2023
·Vol. 15
·期 19
·e202300703
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IF 4.5
Xinzheng Ma,Luyao Guo,Ziang Zhao,Yu Meng,Xiaoling Mou,Ronghe Lin,Yihui Li,Li Yan,Hejun Zhu,Yunjie Ding
Graphical Heptanol oxidation : Melamine modification of commercial activated carbon can greatly tune the performance of Pt−Bi catalysts in n -heptanol oxidation. C 3 N 4 -modified AC favors the formation of PtBi alloy in comparison to N-doped AC, and consequently boosts the activity and selectivity to heptanoic acid. Different bimetallic platinum and bismuth catalysts supported on melamine-modified activated carbon (AC) are designed by a co-impregnation method. Through controlling the activation temperatures of the melamine−AC mixture, a series of N-doped and C 3 N 4 -modified AC (N−AC and C 3 N 4 −AC) are prepared. Combined powder X-ray diffractions, X-ray photoelectron spectroscopic, and high-angle annual dark-field scanning transmission electron microscopic studies demonstrate that the introduction of C 3 N 4 favors the formation of PtBi alloy and leads to increased particle sizes in comparison to the pristine and N-doped AC-supported bimetallics. The catalytic performance of the developed catalysts is evaluated in the oxidation of n -heptanol oxidation in a batch mode using O 2 as the oxidant. PtBi/C 3 N 4 −AC exhibits significantly boosted activity as well as selectivity to heptanoic acid as compared with the other catalysts. A high yield of heptanoic acid of 69 % can be achieved under the optimized reaction conditions. Furthermore, our work points to the PtBi alloy as the most active sites for the alcohol oxidation. Catalyst deactivation occurs in the cycling tests, mainly due to the collapse of the alloy phase and likely the decrease in particle sizes.
研究领域:
催化化学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）