RSC Advances
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2018
·Vol. 8
·期 38
·21480-21494
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IF 2.936
Ruihong Meng,Tan Chen,Yaxin Zhang,Wenjing Lu,Yanting Liu,Tianchu Lu,Yanjun Liu,Hongtao Wang
In this work, a low-cost and available material for use as a permeable reactive barrier (PRB) to prevent vanadium in groundwater from leaking into river water was developed. Three modified biochars were prepared from available corn straw pretreated with CsCl, Zn(II), and Zr(IV) to enhance ion exchange capacity (IEC) and specific surface area, and were designated as Cs-BC, Zn-BC, and Zr-BC, respectively. These materials were characterized via IEC, N2 adsorption–desorption, Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analyses. The Langmuir isotherm model could be applied for the best fit for the adsorption data of Cs-BC and Zr-BC, indicating that vanadium(V) sorption occurred in a monolayer. The vanadium(V) adsorption capacities of Cs-BC, Zn-BC, and Zr-BC were 41.07, 28.46, and 23.84 mg g−1, respectively, which were 3.22–5.55 times higher than that of commercial activated carbon (AC) (7.40 mg g−1), probably because of their higher IECs and specific surface areas after modification. In addition, no heavy metal leaching was found from the modified biochars during the adsorption processes when pH > 2. According to the FTIR and XRD patterns, the adsorption mechanism of Cs-BC and Zr-BC was ion exchange, whereas for Zn-BC, it was mainly surface precipitation and electrostatic attraction. The adsorption of vanadium(V) onto the modified biochars was independent of pH in the range of 4.0 to 8.0. Furthermore, the removal efficiency of the vanadium(V) in real contaminated groundwater from the catchment of the Chaobei River by Zn-BC reached 100% at a dose of 4 g L−1. Hence, modified biochars are promising PRB filling materials for removing vanadium(V) from contaminated groundwater.
研究领域:
环境科学
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材料科学
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DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2017
·Vol. 135
·期 12
·46034
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IF 1.86
Jiqin Chen,Chunhui Shen,Shanjun Gao,Yuan Yuan,Xuechao Ren
Novel organic–inorganic hybrid membranes, based on poly(2,6-dimethyl-1,4-phenylene oxide), have been prepared through 1,2-dimethylimidazole functional groups and double crosslinking agents including 3-glycidyloxypropyltrimethoxysilane and tetraethyl orthosilicate by sol–gel process for the purpose of improving the conductivity and alkaline resistance. The structure of membranes was characterized using Fourier-transform infrared spectra, 1 H NMR, and X-ray diffraction. The physico-chemical properties of all membranes were shown in ion exchange capacity, water uptake, stability, and conductivity. Membranes with OH – conductivity up to 0.022 at 25 °C and 0.036 S cm −1 at 80 °C. Promisingly, the chemical stability of the resulting membranes remains unchanged after storage in 2 mol dm −3 KOH at 25 °C over at least 10 days. The tensile strength can be higher than 30 MPa, and the elongation at break (Eb) is in the range 6.68–10.84%. Hence, this hybrid membrane can be potentially applied in alkaline fuel cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46034.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
APPLIED CLAY SCIENCE
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2020
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IF 4.605
Qiuzhi He,Runliang Zhu,Qingze Chen,Yanping Zhu,Yixuan Yang,Jing Du,Jianxi Zhu,Hongping He
Layer charge is a critical factor determining the structural characteristics and physicochemical properties of clay minerals, and fixing small cations (e.g., Li + ) into the tetrahedral/octahedral sheets of clay minerals is a feasible way for reducing their layer charges. However, conventional methods for preparing reduced-charge clay minerals are usually quite complex and time-consuming. Herein, a facile one-pot treatment method for preparing reduced-charge clay minerals was successfully developed using molten salts . In particular, montmorillonite (Mt) was mixed with mono LiNO 3 or LiNO 3 -NaNO 3 mixture, which was then heated above the melting points of salts. The obtained results showed that the cation exchange capacity (CEC) of Mt decreased evidently after being treated with molten LiNO 3 , and the CEC value was reversely related to the heating time. The X-ray diffraction results demonstrated that Mt layers collapsed upon treatment with molten LiNO 3 . On the other hand, the partial replacement of LiNO 3 by NaNO 3 could restrict the collapse of Mt layers, as the larger ionic radius of Na + (than Li + ) helped in maintaining the interlayer spaces of Mt during the process of charge reduction. As indicated by the Fourier transform infrared spectroscopy, the structural OH stretching vibration shifted to a higher wavenumber (from 3623 to 3632 cm −1 ) after the molten LiNO 3 treatment, which suggested that some Li + ions migrated into the hexagonal cavities in the tetrahedral sheets of Mt, and the new band at 3670 cm −1 indicated that some Li + ions even further migrated into the octahedral vacancies of Mt. The locations of fixed Li + ions were further confirmed by the X-ray photoelectron spectroscopy characterization. Due to the migration of Li + ions into the layers of Mt, the Li1s peak shifted to lower binding energy. The above results showed that the molten salt treatment might be a cost-effective and environmentally friendly approach for synthesizing reduced-charge clay minerals, and using mixed molten salts can help in maintaining the interlayer structure.
研究领域:
矿物学
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材料科学
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DOI
高影响因子
Minerals
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2018
·Vol. 8
·期 8
·338
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IF 1.835
Yating Cui,Yu Zheng,Weiqing Wang
As a solid waste, kaolinite-type pyrite flotation tailings (KPFT) are a type of low-quality kaolin that contain impurities, such as iron and titanium. In this study, KPFT were calcined at 800 °C for two hours. The calcined production (CKPFT), which is mainly metakaolin, was used as the silicon and aluminum source to synthesize 4A zeolite (Na12[(AlO2)12(SiO2)12]·27H2O) via hydrothermal synthesis. The optimal hydrothermal synthesis conditions were determined from X-ray diffraction phase analysis, relative crystallinity (RC), and cation ion exchange capacity (CEC). The optimal hydrothermal synthesis conditions were determined to be a ratio of 5 g CKPFT, 6.5 g NaOH, 65 mL H2O, crystallization temperature 110 °C, and crystallization time of three hours. Under the optimal hydrothermal synthesis conditions, the RC and CEC of the synthesized 4A zeolite were 40.77% and 210.32 mg CaCO3·g−1, respectively. Further characterizations including pore size distribution, scanning electron microscopy, energy dispersive X-ray, thermogravimetry-differential scanning calorimetry, and Fourier transform infrared spectroscopy were performed. The results revealed that impurities in KPFT do not affect the synthesis of 4A zeolite. The surface morphology of the synthesized 4A zeolite was composed of chamfered-edged cubes with a particle size of one to three μm that was thermally stable up to approximately 890 °C.Keywords:kaolinite-type pyrite flotation tailings;4A zeolite;hydrothermal synthesis;calcination;relative crystallinity;cation ion exchange capacity
研究领域:
矿物学
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环境科学
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DOI
高影响因子
Polymer Chemistry
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2018
·Vol. 9
·期 40
·4984-4993
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IF 4.927
Chenyi Wang,Yuanpeng Zhou,Bin Shen,Xiaoyan Zhao,Jian Li,Qiang Ren
Aromatic sulfonated polymers are a class of important proton exchange membranes. With the aim of further enhancing their properties at low levels of ion-exchange capacity (IEC), a class of new poly(ether sulfone ketone)s containing multiple sulfonic acids on the side chains of the sulfonated structural units (sPh-PESK-xx) were designed and prepared by a convenient and mild post-sulfonation reaction process. The structures of the related monomer and copolymers were confirmed by IR and NMR analysis. The resulting membranes from solution casting of these aromatic sulfonated polymers showed overall good performance at low IEC levels. Their proton conductivities were in the range of 110–154 mS cm−1, while their swelling ratios were in the range of 6.2%–16.1% at 80 °C. Meanwhile, they also displayed good thermal and chemical oxidative stabilities. The results confirmed that the incorporation of a high density of pendant sulfonic groups is an effective way to improve the performance of aromatic sulfonated polymers.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Geting Xu,Binghui Wang,Jingwen Xu,Edison Huixiang Ang,Junbin Liao,Jiangnan Shen
This study involves the development of a series of primary and secondary crosslinked anion exchange membranes (AEMs) within PVDF semi-interpenetrating networks, establishing a stable ion exchange structure. The optimal AEM, identified as DAEM-3, exhibits an ion exchange capacity (IEC) of 0.92 mmol·g −1 , a solute diffusion rate of 0.0076 mmol/(cm 2 ·h·mol/L). Remarkably, the desalination rate could reach 95.66 % within 180 min at a current density of 15 mA·cm −2 , with the current efficiency of 81.12 %, surpassing the performance of the commercial membrane (AMX). Furthermore, the concentration rate reaches 17.00 % during a 390-minute process at a current density of 50 mA·cm −2 , highlighting the ability of secondary cross-linking to simultaneously regulate IEC and the degree of cross-linking for improved densification and ion exchange performance. Moreover, the relatively tight cross-linked structure could be found to reduce water permeability and slow down the rate of spontaneous solute diffusion, making it a promising advancement in ED desalination and concentration technologies applied in zero liquid discharge.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
TALANTA
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2016
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IF 4.035
Qiming Zhao,Shuchao Wu,Peimin Zhang,Yan Zhu
Monodisperse carbonaceous spheres produced by the hydrothermal carbonization of sucrose were first applied as green stationary phase for ion chromatography after quaternization . Depending on the polycondensation of methylamine and 1,4-butanediol diglycidyl ether, polymer containing quaternary ammonium groups were facilely grafted onto the surfaces of hydrothermal carbonaceous spheres (HCSs). The quaternized HCSs with different number of polyelectrolyte layers were characterized by scanning electron microscopy, brunauer-emmett-teller, fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and elemental analysis . The measurements of breakthrough curves demonstrated that more layers of grafted polyelectrolyte resulted in higher anion exchange capacity of stationary phase. With good stability, common inorganic anions , monocarboxylic acids , polarizable anions and carbohydrates were effectively separated on the stationary phases, respectively. The high hydrophilicity of HCS surface afforded excellent peak symmetry for all analytes. Furthermore, high-capacity HCSs stationary phase was successfully applied to detect fluoride in tea samples.
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
Journal of Materials Chemistry A
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2018
·Vol. 6
·期 48
·24831-24840
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IF 9.931
Ling Li,Qian Yang,Xue Lang Gao,Hong Yue Wu,Qiu Gen Zhang,Ai Mei Zhu,Qing Lin Liu
With the aim of preparing highly alkaline stable anion-exchange membranes (AEMs) with desirable ionic exchange capacity (IEC) and swelling, a series of crosslinked poly(4-vinylphenol) (PVP)-based membranes was prepared. A facile crosslinking method using bis(hydroxymethyl)-4-cresol (BHMC) as the crosslinker was introduced in the preparation of AEMs to avoid sacrificing specific functional groups such as –OH in the backbone. It is worth mentioning that the whole procedure for membrane preparation was efficient and easy to handle. The as-prepared membranes exhibited pretty low water uptake and swelling by the introduction of a crosslinked structure. Microphase separation to different extents could be observed in the membranes with different degrees of crosslinking via transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). The QAPVP-5% membrane with an ionic exchange capacity (IEC) of 2.12 meq g−1 displayed the highest ionic conductivity of 78 mS cm−1 at 80 °C. Moreover, the all-carbon backbone endowed an excellent alkaline stability of the membranes, and the QAPVP-5% membrane still retained 91.3% of its original conductivity after immersing in a 2 M aqueous KOH solution at 80 °C for 480 h. A peak power density of 122 mW cm−2 was also obtained by a single cell equipped with the QAPVP-5% membrane.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Journal of Materials Chemistry A
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2015
·Vol. 3
·期 24
·12698-12708
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IF 7.443
Sinan Feng,Guibin Wang,Haibo Zhang,Jinhui Pang
A series of octa-sulfonated poly(arylene ether)s (PAEs) was prepared via a low-temperature grafting reaction and subsequent postsulfonation. The rigid backbone with high molecular weight is conducive to higher integrity of the hydrophobic domain. And the grafting ionic clusters are expected to promote the appearance of phase separation. These membranes, with ion exchange capacity (IEC) values ranging from 1.19 to 1.90 meq. g−1, exhibited excellent dimensional stability, mechanical properties and oxidative stability. The membrane with higher IEC (>1.4 meq. g−1) exhibited adequate conductivity (>100 mS cm−1) in water at 80 °C. Furthermore, the membrane with IEC = 1.90 meq. g−1 exhibited comparable conductivity to Nafion 117 under various humidity levels. In addition, SAXS profiles confirmed the well-defined phase-separated morphology of SPAE-x. DMFC single cell performance demonstrates that SPAE-x are good candidates for proton exchange membranes in fuel cell applications.
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
JOURNAL OF MEMBRANE SCIENCE
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2024
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IF 8.4
Huimin Ruan,Zhihao Lin,Shangshang Gao,Junbin Liao,Arcadio Sotto,Yuyang Yao,Zhipeng Xu,Jiangnan Shen,Edison Huixiang Ang
Electrodialysis (ED) was widely use for sulfuric acid (H 2 SO 4 ) recovery. However, challenges such as proton leakage during ED processes and the presence of large amounts of organic solvents in the wastewater have limited the recovered acid concentration to less than 30 wt% and shortened membrane lifespan. In this study, we prepared a series of anion exchange membranes (AEMs) using 3-aminopropyltrimethoxysilane (APTMS) and phenyltriethoxysilane (phTES) as cross-linking agents aimed at concentrating H 2 SO 4 through the ED process. As the content of bis-siloxane crosslinkers increased, the ion exchange capacity (IEC) of the membranes decreased from 1.86 to 1.27 mmol g −1 , resulting in lower water flux and membrane conductivity. However, the increased crosslinker content significantly enhanced membrane hydrophobicity, thereby improving its acid-blocking properties. During ED operations at a current density of 10 mA cm −2 , the BPPO-10APTMS-10phTES membrane achieved a H + concentration of 2.15 mol/L (from an initial concentration of 1.00 mol/L), outperforming AEMs without cross-linking structure. Additionally, the BPPO-xAPTMS-xphTES membranes (x = 5, 10, and 15) exhibited strong resistance to organic solvents. This research offers valuable theoretical guidance for developing AEMs with enhanced acid concentration capabilities and solvent resistance.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
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2020
·Vol. 58
·期 3
·391-401
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IF 0
Jinwu Peng,Zhenchao Liu,Minhui Liang,Peng Wang,Wei Hu,Zhenhua Jiang,Baijun Liu
In the field of the developments of next-generation polymer electrolyte membranes, high conductivity is often regarded as the first important performance requirement. There is still a huge challenge to face, which is hard to achieve the balance between high ion conductivity (mainly related to ion-exchange capacity [IEC]) and good mechanical-dimensional stability (represented by swelling ratio [SR]). Here, a family of crosslinked block polyelectrolytes consisting of hydrophobic rigid poly(arylene ether sulfone) segments to ensure enough dimensional stability and hydrophilic poly(phenylene oxide) segments bearing long-flexible chains with high-density multications to serve as crosslinker and carrier for ion transport are prepared. The polyelectrolyte with an IEC of 3.04 mmol g −1 exhibits a high hydroxide conductivity of 126 mS cm −1 and a low SR of 8.6% at 80 °C. No obvious degradation below 200 °C is observed, and maximum tensile strength reaches 28.4 MPa. As a conclusion, these crosslinked membranes based on well-designed block polyelectrolytes exhibit an excellent combination of high ion conductivity and good mechanical-dimensional stability to meet the performance requirements for the application of anion-exchange membranes. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58 , 391–401 Graphical The novel anion-exchange membranes (AEMs) having a unique crosslinked “ladder-like” chemical structure are prepared after a series of chemical reactions. Continuous conductive domains from hydrophilic areas are beneficial to OH − transport owing to locally high concentration of cations gathering. The medium-length densely crosslinked chains not only ensure the flexibility of AEMs, but also limit the excessive swelling ratio at high temperature. Meanwhile, the crosslinked AEMs exhibit improved alkaline stability due to the hindrance to OH − attack. In a word, the block polyelectrolytes with crosslinked hydrophilic segments display an excellent overall performance for AEMs. The figure shows the suggested OH − transport path in AEMs.
研究领域:
材料科学
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化学工程
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DOI
CHINESE JOURNAL OF POLYMER SCIENCE
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2022
·Vol. 40
·期 7
·754-763
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IF 3.815
Chen Xing,Xiao Lei,Qiu Xin-Sheng,Chen Kang-Cheng
A series of multiblock sulfonated poly(arylene ether sulfone)s (SPAES) with various block lengths and predictable ion exchange capacity were synthesized from 4,4′-difluorodiphenyl sulfone, 4,4′-dihydrodiphenyl sulfone and 4,4′-biphenol by one-pot and two-pot polymerization. 1 H-NMR and FTIR spectra confirmed the structure that sulfonic acid groups were introduced precisely on the poly(arylene ether sulfone)s by post-sulfonation which resulted in controllable sulfonation degree. The proton exchange membranes (PEMs)-based SPAES displayed excellent dimensional, thermal, antioxidant stability, proton conductivity and mechanical properties (maximum tensile stress >35 MPa). Thermogravimetric analysis indicated the prepared SPAES began to degrade above 310 °C. The effects of polymerization processes, those were, one-pot hydrophobic segment process, one-pot hydrophilic segment process and two-pot process, on the properties of polymers were investigated. The proton conductivity and microphase separation of SPAES PEMs increased in order of those prepared by one-pot hydrophobic segment process, two-pot process and one-pot hydrophilic segment process. The highest conductivities of SPAES synthesized by the above processes under 80 °C and 100% relative humidity were 213 (MS4), 297 (MB3) and 360 mS·cm −1 (MQ2), respectively.
研究领域:
材料科学
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化学工程
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能源技术
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DOI
高影响因子
危险品化学品经营许可证（带存储）