IONICS
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2023
·Vol. 29
·期 12
·5383-5396
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IF 2.8
Xu Guoyang,Zhou Weiyang,Jiang Yingshan,Zhang Qingshi,Li Xiangdan,Zhang Aiqing
A series of gemini cationic fluorinated poly(aryl ether) anion exchange membranes (AEMs) with different photocrosslinking degrees were prepared. The AEMs with photosensitive structures can photocrosslink under UV irritation at room temperature in the swollen state. Atom force microscope (AFM) experiment confirmed that the membranes had obvious hydrophilic/hydrophobic microphase separation structure. The ion exchange capacities (IEC), water uptake, swelling rate, ionic conductivity, mechanical properties, and thermal stability of the membranes were also investigated. The IECs were in the range of 2.05–2.16 meq/g, but AEMs showed reasonable water uptakes and swelling ratio were 39.67 and 14.47% at 80 °C, respectively, due to the introduction of fluorine atoms. The crosslinked membranes still exhibited satisfying hydroxide conductivity with a maximum value of 133.44 mS/cm at 80 °C. It can be attributed to the formation of hydrophilic/hydrophobic microphase separation structure within the membrane and the development of a tremendous number of ion transport channels. The conductivity only decreased by 6.3% correspondingly after in 1 M NaOH at 60 °C for 7 days; indicating membranes have good alkaline stability.
研究领域:
材料科学
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高分子科学
·
电化学
·
能源技术
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
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2021
·
IF 4.598
Na Yu,Jianhao Dong,Huanhuan Li,Tingting Wang,Jingshuai Yang
Polystyrene- b -poly(ethylene-co-butylene)- b -polystyrene (SEBS) has attracted more and more attention recently for using as the matrix of anion exchange membranes (AEMs) in fuel cells due to its low cost, superior mechanical properties and ether-free total C-C bond backbone. In this work, the short side chain of chloromethyl and long side chain of bromohexanoyl groups are grafted into the SEBS copolymer via the chloromethylation and Friedel-Crafts acylation reactions. After quaternized by different nitrogen heterocyclic compounds including 1-methylimidazole (Im), 1-methylpyrrolidine (Mpy), N -methylpiperidine (Pip) and 2-methyl-1-pyrroline (Mpyl), various SEBSC n - x AEMs are prepared. Combing with small molecule model experiment results, Mpy and Pip cations grafted SEBS membranes are confirmed to possess good alkali resistance, while SEBSC1- x membranes with Im and Mpyl cations are not suitable for AEMs due to their poor alkaline stability. Meanwhile, long side-chain cation grafted SEBSC6- x AEMs with lower ion exchange capacity (IEC) values exhibit higher water uptake, ionic conductivity and mechanical strength simultaneously comparing with short side-chain cation grafted SEBSC1- x AEMs. As an example, the SEBSC6-Pip membrane with an IEC of 0.48 mmol g −1 exhibits a water uptake of 47% at 80 °C, an OH − conductivity of 57.7 mS cm −1 at 80 °C, a tensile strength of 52 MPa at room temperature, and a conductivity retention percent of 75% after 600 h in 1 M KOH at 80 °C, demonstrating a big potential for the AEM fuel cell application.
研究领域:
高分子科学
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膜技术
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燃料电池
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材料科学
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电化学
✓ 已验证
DOI
高影响因子
GEODERMA
·
2022
·
IF 7.422
Ke-wei Li,Hai-long Lu,Jackson Nkoh Nkoh,Zhi-neng Hong,Ren-kou Xu
Soil acidification is an increasing challenge to food security due to the production of free aluminum ion (Al 3+ ) that is toxic to crops. The production of exchangeable Al 3+ in soils during acidification is a complex process and its specific mechanism is not clear. In this study, kaolinite, montmorillonite, and three acidic soils (two Ultisols and one Alfisol) were used to investigate the changes in exchangeable and soluble Al with pH using a constant pH automatic potentiometric titrator. The effect of soil organic matter (SOM) on soil pH and Al change was also investigated. The results showed that montmorillonite consumed more acid than kaolinite under the same conditions, which were consistent with the larger cation exchange capacity (CEC) of montmorillonite than kaolinite. When the pH was adjusted from 4.8 to 4.3, the exchangeable Al of montmorillonite was significantly higher than that of kaolinite. This was consistent with their CEC and indicated that montmorillonite adsorbed more H + than kaolinite at the same pH, resulting in more exchangeable Al on its surface. Besides CEC, SOM shows a significant effect on acid buffering capacity and Al activation of acid soils. When acidified to the same pH, the content of exchangeable Al in Alfisol was larger than that in Ultisols. This observation was consistent with the larger CEC and smaller organic matter content of Alfisol. The presence of more organic matter in the Ultisols not only improved their acid buffering performance, but also inhibited the production of exchangeable and soluble Al. In conclusion, CEC of soils and minerals play an important role in soil acid buffering performance. While, SOM not only improves soil acid buffering performance, but also inhibits the mobilization of soil Al.
研究领域:
土壤学
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Xinming Du,Yongjiang Yuan,Tianming Dong,Xiaoyu Chi,Zhe Wang
Fuel cells (FCs) have attracted much attention because of their high energy conversion efficiency and cleanliness. However, polyelectrolytes are a key component of FCs, and their cost and performance are not ideal at present, which is an obstacle to the development of FCs. Polymers of intrinsic microporosity (PIM) have attracted much attention as a class of membrane materials due to their three-dimensional pore structure, which can provide channels for ion transport. However, it remains challenging to prepare PIM membranes due to their poor solubility and brittleness. A novel soluble Troger’s base (TB)-PIM polymer is proposed in this paper. The prepared TB-based membranes with rigid and contorted backbones exhibit excellent dimensional stability (<8% swelling ratio at 60 °C), mechanical properties, and thermal stability and form subnanometer cavities to allow rapid ion transport. Therefore, the proton conductivity of the 4-(2-hydroxyethoxy)-1,3-phenylenediamine dihydrochloride (HEPD)/4,4′-diamine-3,3′-dimethyl-biphenyl (DMBP)-TB membrane is 58.3 mS/cm at 80 °C. The OH– conductivity of the HEPD/DMBP-QTB anion exchange membrane (AEM) is 105.9 mS/cm at 80 °C. Moreover, the single cell assembled with an HEPD/DMBP-QTB AEM showed a peak power density of 76.6 mW/cm2 in H2 air (CO2-free) at 60 °C.
研究领域:
材料科学
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能源技术
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Hefang Liu,Shunyan Ning,Shichang Zhang,Xinpeng Wang,Lifeng Chen,Toyohisa Fujita,Yuezhou Wei
Palladium , as a member of platinum group metals , has very little reserve in nature. It usually plays a role in corrosion resistance in the electroplating industry, and is easily discharged into electroplating wastewater during processing. Therefore, it is of great significance to develop efficient functional materials which can rapidly and selectively capture Pd(II). Herein, a mesoporous ion exchange resin (SiAaC) based on a silica framework was designed and synthesized by in situ polymerization method to efficiently remove Pd(II) from simulated electroplating wastewater. SiAaC exhibited unique advantages over traditional commercial resins, such as high adsorption capacity (121.8 mg/g), high selectivity ( SF Pd/M >230 in 0.01 M HNO 3 solution) and excellent reusability (n > 5). The adsorption results of SiAaC resin on Pd(II) are consistent with Langmuir isotherm and pseudo-second-order kinetic models . In addition, the column experiment can efficiently separate Pd(II) from simulated electroplating wastewater. Furthermore, FT-IR and XPS spectra proved an ion exchange mechanism between SiAaC and Pd(II). In general, this research not only demonstrated an excellent material which can effectively and efficiently remove low-level palladium from simulated electroplating wastewater, but also provided a new perspective for the synthesis or improvement of ion exchange resins.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 47
·29794-29805
·
IF 3.108
Abhishek N. Mondal,Yubin He,Liang Ge,Liang Wu,Kamana Emmanuel,Md. Masem Hossain,Tongwen Xu
A novel side-chain-type anion exchange membrane (AEM) is synthesized using thiol-ene click chemistry and the Menshutkin reaction. The prepared membranes are fully characterized and successfully mitigate the trade-off between conductivity and water uptake. Side-chain-type polymer electrolyte membranes with moderate hydroxide conductivity and improved water uptake are obtained. The thiol-ene click reaction is employed for the synthesis of active monomer 9-(2-((3-(triethoxysilyl)propyl)thio)ethyl)-9H-carbazole (TESPTEC). Using the Menshutkin reaction, TESPTEC is introduced into the brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) backbone. The NVC-50 membrane shows a maximum hydroxide conductivity of 19.84 ± 1.81 mS cm−1 at 20 °C, and 54.69 ± 2.91 mS cm−1 at 60 °C. However, at 20 °C, the water uptake of the membrane NVC-50 is only about 18.36 wt%. After 12 days of alkaline treatment, the NVC-50 membrane shows better alkaline stability than the conventional QPPO membrane.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Progress in Natural Science-Materials International
·
2021
·
IF 3.607
Jiaojiao Zheng,Bing Bai,Qiumei Di,Zhuoli Jiang,Meng Xu,Jiatao Zhang
In II-VI group, the doping in CdTe nanocrystals (NCs) is more difficult than other chalcogenides. In this communication, CdTe nanocrystals containing Cu impurities were carefully synthesized based on controlled reverse cation exchange process between as-prepared Cu 7 Te 5 nanocubes and Cd 2+ ions. By well-defined Cu 7 Te 5 nanocubes, the obtained CdTe NCs kept the original morphology. The concentration of Cu impurities in CdTe NCs was controlled by the regulation such reverse cation exchange. Additionally, the regulation from band gap (BG) photoluminescence (PL) to the coexistence of the bandgap emission, dopant emission, and surface-state emission was realized. This tailoring from undoped to doped emission in the case of Cu impurities is helpful to study the Cu related doping in telluride NCs.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Hui Wang,Xinming Du,Hongyu Zhang,Hongcheng Shen,Qian Liu,Zhe Wang
A series of quaternary ammonium salt poly(ether ether ketone) AEMs containing long ether substituents are successfully prepared, and their chemical structure is confirmed by 1 H NMR and FT-IR. The distinct microphase separation morphology of AEMs is observed by TEM. As the content of methylhydroquinone increases, the ion conductivity of AEMs gradually increases. When the content of methylhydroquinone increases to 80%, the hydroxide conductivity of PEEK-DABDA-80 membrane reaches 0.052 S/cm at 80 °C. Meanwhile, it exhibits excellent mechanical properties and anti-swelling ability, with tensile strength of 25 MPa, elongation at break of 8.12% and swelling ratio is only 17.4% at 80 °C. And AEMs also display the better thermal stability. After soaked in 1 M NaOH at 60 °C for 30 days, PEEK-DABDA-80 membrane shows acceptable ion conductivity of 0.021 S/cm at 60 °C. In view of these properties, PEEK-DABDA-x AEMs may display potential application as alkaline AEMs.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
·
2018
·
IF 0.824
Meng-Fei LAN,Ning AN,Ying ZHAO,Wei CAO,Heng LI,Lan ZHAO,Yong-Dong HUANG,Rong-Yue ZHANG
The macroporous microspheres were prepared through suspension polymerization based on a copolymer of glycidyl methacrylate and ethylene glycol dimethacrylate. The effect of porogen on the microspheres structure was evaluated in terms of pore size and surface area. Porogen contained dichloromethane ( δ = 9.7 (cal cm –3 ) 1/2 ) and N -octanol ( δ = 10.3 (cal cm –3 ) 1/2 ) which were correspond to a good and poor solvent, respectively. The solubility parameter of porogen was controlled in the range of 9.89–10.09 (cal cm –3 ) 1/2 . The pore size of microspheres increased with the increase of difference value of solubility parameter between the polymer and the porogen. On the contrary, the surface area of microspheres decreased. The anion exchange media was prepared through coupling poly(ethylene imine) in the microspheres and the proteins transport was determined by frontal analysis method. The macroporous microspheres with 257 nm pore size could still afford a high proteins capacity (45.1 mg mL –1 ). These macroporous supports showed great potential in rapid separation of proteins.
研究领域:
生物技术
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Li Gao,Ying Wang,Chunyu Cui,Wenji Zheng,Xiaoming Yan,Peng Zhang,Lei Hu,Xuemei Wu,Lin Zhuang,Gaohong He
Developing anion exchange membranes (AEMs) having high hydroxide conductivity, swelling resistance and excellent alkaline stability is a challenge for fuel cells now. Herein, a universal and controllable approach of grafting rigid side chain is first proposed to construct connected ion transport nano-channels. A new route is also provided to prepare AEMs with stable symmetric saturated heterocyclic amomium. The rigid side chain is introduced onto poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) by the Friedel-Crafts acylation with 4-fluorobenzoyl chloride and subsequent reaction between phenyl fluoride and secondary amine of 1-methylpiperazine. Then the terminal piperazinium is produced by the reaction between tertiary amine of 1-methylpiperazine and methyl iodide. Rigid branches expand free volume to construct connected ion transport nano-channels, leading to excellent conductivity (108 mS cm −1 at 60 °C) that is higher than those of other reported symmetric heterocyclic amomium functionalized AEMs (33–89 mS cm −1 at 60 °C). Due to the high conductivity, the H 2 /O 2 cell employing this membrane achieves one of the highest peak power densities (1210 mW cm −2 at 2600 mA cm −2 ) so far. In addition, the IEC of the membrane remains constant after testing in 1 M NaOH at 60 °C over 500 h.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Maolian Guo,Tao Ban,Yajie Wang,Yannan Wang,Yiyang Zhang,Jingsong Zhang,Xiuling Zhu
A series of ether-free polybenzimidazoles (PBIs) containing alicyclic and aliphatic segments were synthesized for the application of anion exchange membranes (AEMs). The PBI-based AEMs prepared in this work (denoted as Pip-PBIs) possessed both high anionic conductivity and alkaline stability by grafting long alkyl chain 1-methylpiperidinium. Benefiting from the random arrangement of aromatic-alicyclic/aliphatic in backbone and their flexible spatial configurations, most Pip-PBIs showed significantly improved solubility in low boiling point solvents namely methanol and isopropanol, which could allow it as ionomer to improve the phase interface between catalyst and AEMs. Meanwhile, the flexible segments in backbone contributed to the formation of ion conductive channel, the Pip-PBI-C achieved the highest hydroxide ions conductivity of 108.8 mS cm −1 at 80 °C, and the conductivity could retain 82.9% after soaking in a 2 M aqueous NaOH at 80 °C for 1536 h. Furthermore, Pip-PBIs demonstrated well oxidation stability in Fenton's reagent (4 ppm FeSO 4 and 3% H 2 O 2 ). Moreover, the H 2 –O 2 fuel cell using Pip-PBI-C as membrane achieved a high open circuit voltage of 1.0 V and a peak power density of 785.6 mW cm −2 at the current density of 1802.9 mA cm −2 .
研究领域:
材料科学
·
化学工程
·
能源技术
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2019
·
IF 3.858
Linling Yu,Qiuhong Zhai,Yan Sun
Our previous studies on protein adsorption to the anion-exchangers of poly(ethylenimine) (PEI)-grafted Sepharose FF found that both adsorption capacity and uptake rate of bovine serum albumin (BSA) increased greatly when the PEI grafting density reached over a critical ionic capacity (cIC) due to the 3D protein binding and occurrence of “chain delivery” of bound proteins. Moreover, by the investigation on the anion-exchangers of diethylaminoethyl (DEAE)-modified and DEAE-dextran-grafted Sepharose FF, we found the unique role of surface ligand in facilitating protein uptake kinetics on dextran-functionalized anion exchangers as the “transfer station” for the “chain delivery” of bound proteins. However, what would be the contribution of surface ligands on the transport of bound proteins on PEI chains at a wide range across cIC, particularly at the lower IC range where no “chain delivery” was present? We have thus designed this research to answer the question. To this purpose, we fabricated three series of PEI-Sepharose FF resins, one without surface ligand (i.e., FF-PEI) and two with surface DEAE modifications at DEAE coupling densities of 60 and 90 mmol/L (i.e., FF-D60-PEI and FF-D90-PEI), and focused on the role of surface DEAE at different PEI densities in BSA adsorption equilibrium and uptake kinetics in a wide IC range of PEI across cIC (∼600 mmol/L for BSA). It was found that, at low grafting-ligand densities (IC cIC, however, both adsorption capacity and uptake rate changed only slightly (<5% and <10%, respectively) by the addition of surface DEAE groups. The results revealed that at IC < cIC, the surface DEAE groups provided the supplement of available binding sites and facilitated the happenings of the “chain delivery” of bound proteins as the “transfer station”, both of which were limited at the low IC range. However, at IC > cIC, the extended flexible PEI chains have already afforded 3D binding space with high accessibility and easy happening of “chain delivery” of bound proteins, so the surface DEAE groups between neighboring PEI chains did not work in assisting the transport of bound proteins. Moreover, when the IC was lower but close to the cIC, the FF-D-PEI resins exhibited higher uptake rates than FF-PEI resins at a similar or even lower IC values. These findings indicate that surface modification of charged groups in PEI-based anion exchangers of low grafting density would be an efficient strategy to fabricate high performance protein ion exchangers.
研究领域:
生物化学
·
分离科学
·
蛋白质工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）