JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 9
·1-12
·
IF 2.184
Han Wenfeng,Li Xiaojuan,Tang Haodong,Wang Zhikun,Xi Miao,Li Ying,Liu Huazhang
Abstract A Cr 2 O 3 hexagonal prism structure synthesized via the reaction of aqueous CrCl 3 solution with NaBH 4 solution at room temperature followed by calcination of the precipitate in N 2 atmosphere at 500 °C is investigated as an efficient catalyst for dehydrofluorination of 1,1-difluoroethane producing vinyl fluoride. With the assistance of scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy, experimental results revealed that the uniform hexagonal prism has a prism length of 285 ± 43 nm and width of 233 ± 33 nm. It is in the form of loose and net-like aggregation of nano-Cr 2 O 3 with diameter less than 3–5 nm with polycrystalline structure. NH 3 temperature programmed desorption and chlorodifluoromethane dismutation experiments confirm the existence of relatively abundant and strong acidic sites. As a catalyst for dehydrofluorination of 1,1-difluoroethane, compared with commercial Cr 2 O 3 , much higher activity and stability were observed due to the evolution of CrO
x
F
y
species and much higher surface area and mesoporous structure. No significant morphology changes or sintering of the catalyst are observed after 70-h reaction. Compared with the commercial Cr 2 O 3 , we suggest that the much smaller size of Cr 2 O 3 crystalline which possesses higher surface energy, lower strength, and more abundant Lewis acidity and the formation of CrO
x
F
y
during reaction over hexagonal prism catalyst probably contributes to the activity and stability difference between these two catalysts. Graphical Abstract
研究领域:
材料科学
·
催化化学
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产品关联
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Yihua Chen,Jiaxin Zhu,Hang Ma,Yurong Gu,Tongzhou Liu
Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant posing a risk in environmental persistence, bioaccumulation and biotoxicity. This study was to reach a comprehensive and deeper understanding of PFOS elimination in a UV 254 photolytic treatment with the co-presence of Fe 2+ and nitrilotriacetic acid trisodium salt (NTA). PFOS defluorination was noticeably enhanced in the UV/Fe 2+ -NTA treatment compared with UV/NTA, UV/Fe 2+ and our previously studied UV/Fe 3+ treatments. UV–vis, FTIR, and UPLC/MS-MS results indicated the formation of PFOS-Fe 2+ -NTA complex in PFOS, Fe 2+ and NTA mixture. The transition energy gap of PFOS-Fe 2+ -NTA decreased below the excitation energy supplied by UV 254 irradiation, corresponding with red shift appearing in UV–vis scanning spectrum. This favored intramolecular electron transfer from Fe 2+ -NTA to PFOS under UV 254 irradiation to form electron-accepting PFOS. Molecular electrostatic potential and atom charge distribution analyses suggested electron density rearrangement and perturbation in the perfluorinated carbon chain of electron-accepting PFOS, leading to the decrease in bond dissociation energies. Intermediate products detection suggested the parallel defluorination pathways of PFOS desulfonation, middle carbon chain scission and direct C-F cleavage. NTA exhibited crucial functions in the UV/Fe 2+ -NTA treatment by holding Fe 2+ /Fe 3+ in soluble form as a chelant and favoring water activation to generate hydrated electrons (e aq − ) under UV irradiation as a photosensitizer. Fe 2+ acting as the conduit for electron transfer and the bridge of PFOS anion and NTA was thought functioning best at 200 µM in this study. The degree of UV/Fe 2+ -NTA -synergized PFOS defluorination also depended on e aq − yield and UV 254 photon flux. The structure dependence on the electron transfer process of PFOS and PFOA was explored incorporating molecular structure descriptors. Because of possessing greater potential to acquire electrons or less likeliness to donate its electrons than PFOA, PFOS exhibited faster defluorination kinetics in the published “reduction treatments” than “oxidation” ones. Whereas, PFOA defluorination kinetics were at similar level in both “reduction” and “oxidation” treatments.
研究领域:
环境科学
·
化学
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产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xiaoyu Zhang,Yi Zhang,Huayang Xun,Yuxin Xu,Liyuan Zhang,Jian Fang,Haitao Niu,Hua Zhou
The process of industrialization has led to an increasingly deteriorating environment for human survival, accompanied by the frequent occurrence of air pollution and extreme weather. Filtration is one of the most direct and effective methods for removing harmful particles from the air and improving production cleanliness. Industrial waste gas is detrimental and has a complex composition. Therefore, there is an urgent need to develop high-performance air filtration materials with excellent liquid barrier properties, resistance to hazardous chemicals, and high climate adaptability. Herein, a robust fluorinated metal organic framework (F-MOF) @polyetherimide/polyvinylidene fluoride-hexafluoropropylene/fluorinated alkyl silane (PEI/PVDF-HFP/FAS) nanofiber membrane for high-performance air filtration in complex and harsh conditions is developed. The prepared nanofiber membrane shows superhydrophobicity/oleophobicity with a water contact angle (WCA) of 162° and an oil contact angle (OCA) of 145°. It also shows excellent resistance to organic solvents and corrosive solutions, as well as extreme high/low temperature (200 ℃ / −20 ℃) resistance. Attributed to its outstanding characteristics, the membrane has high filtration performance for both solid and liquid aerosols and maintains long-lasting filtering performances in real situations (i.e., sunlight irradiation, strong wind, rainstorm) and harsh conditions (i.e., strong acid or alkaline). Such nanofiber membrane has broad application prospects in industrial filtration and personal protection in complex and even hazardous conditions.
研究领域:
材料科学
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环境科学
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纳米技术
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产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHIC SCIENCE
·
2025
·Vol. 63
·期 7
·
IF 1.3
Cao Lihua,Ding Youchao,Qian Kai,Wang Xiangxiang,Wang Xiaoqiong,Zhou Jia,Tang Juan
A screening method was developed for the determination of per- and polyfluoroalkyl substances in textiles by combustion and ion chromatography. In this work, a new type of high-temperature combustion absorption device was designed, and the samples were burned, cracked and gasified by temperature programmed heating mode. The produced free fluorine and hydrogen fluoride gases were absorbed by water vapor and completely transformed into inorganic fluoride anion. After condensation and collection, it was separated and determined by ion chromatography. The pre-treatment conditions were optimized including the sample weight, the combustion method, the combustion gas and its flow rate, the water evaporation rate and the condensate collection method. Method validation was performed in negative samples of cotton, wool and polyester, at spiked levels of 5, 50 and 200 mg/kg, respectively. The average recoveries were between 85.7 and 95.0% with relative standard deviations <20% (n = 7) indicating satisfactory accuracy and repeatability. The calibration curve was performed with the correlation coefficients (R2) higher than 0.999 within a linearity range of 0.01–2.0 mg/L. The limit of quantification was 5.0 mg/kg. The developed method was successfully used to determine the total fluorine in market samples. It can meet the screening determination of PFAS in various textiles.
研究领域:
分析化学
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环境科学
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材料科学
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纺织工程
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化学分析
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Xiaoya Zhao,Jilin Zhang,Zi Dai,Yunyun Lei,Xiaoxun Liu,Guixia Liu
Excess fluoride in drinking water from groundwater can cause dental and skeletal fluorosis affecting millions of people worldwide. Adsorption is an appealing strategy for defluoridation due to its simple operation and environmental friendliness. However, conventional adsorbents exhibit low adsorption capacity because few exposed active sites. In this work, La anchored Zr-based metal-organic framework (La-UiO-66-(COOH) 2 ) adsorbent with dual-metal sites was designed and synthesized to remove fluoride effectively. The doping of La(III) using uncoordinated carboxyl group of UiO-66-(COOH) 2 increased the adsorption capacity. The morphology, composition, structure, surface area, and thermal stability of adsorbent were carefully characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectrometer (EDX), fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) techniques. The adsorbent is a polyhedral shape with aggregated and smaller crystalline particles and La is uniformly distributed over the adsorbent, favoring the effective adsorption of fluoride. La-UiO-66-(COOH) 2 showed excellent adsorption performance in a wide pH range of 3–9, and the maximum adsorption capacity was 57.23 mg g −1 . The fluoride removal rate of as-prepared adsorbent reached as high as 87 % within 5 min. The adsorption process conformed to the pseudo-second-order equation model and the Freundlich isotherm model. Thermodynamic research indicated that the adsorption process was spontaneous and endothermic. After four adsorption-desorption cycles, the fluoride removal rate of the adsorbent was still retained at 79.7%. The design of dual-metal site adsorbents provides a potential strategy for highly efficient removal of fluoride.
研究领域:
环境科学
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材料科学
·
水处理
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 11
·115325
·
IF 1.449
Yujiu Zhou,Qingxia Liu,Fujia Chen,Yuetao Zhao,Wenyao Yang,Xin He,Xiling Mao,Yajie Yang,Jianhua Xu
Polymer dielectric materials are highly desirable in electronic devices. However, neither low nor high dielectric constant polymers could meet the requirement of high energy storage application due to the contradiction between dielectric constant and breakdown strength. Herein, in order to obtain high performance polymer dielectrics, poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) is filled, as a functional material, into polyurea (PUA) matrix to form all-organic composites. Fortunately, PUA/P(VDF-TrFE-CFE) composites exhibit excellent performance with high dielectric constant and maintain high breakdown strength, resulting in enhanced energy storage density. The breakdown strength of composite film increases to 5130 kV cm−1, and the energy storage density can reach 4.3 J cm−3, which is much higher than pure PUA (2.4 J cm−3) and commercially biaxially oriented polypropylene (BOPP, 1.2 J cm−3). The enhancement of energy density of composite films is mainly attributed to the dipole interaction between PUA and P(VDF-TrFE-CFE) chains, which leads to increases of dielectric constant and maintain high breakdown strength simultaneously. This work provides an effective route to improve the energy density of linear dielectrics and showing great application potential for energy storage.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 16
·14161-14169
·
IF 2.324
Xiong Xiaoying,Zhou Zhou,Zhang Zhao,Yang Hui,Zhang Qilong
In this study, rod-like TiO 2 filler was synthesized one-step hydrothermal method and was incorporated into P(VDF-TrFE-CFE) polymer matrix to obtain composites with high dielectric constant. It is found that the morphology and content of TiO 2 fillers play a vital role in tailoring the performance of the as-fabricated composites. The rod-like TiO 2 assembled by numerous nanoparticles maintained its primary shape and homogenously distributed in the matrix, thus achieved sophisticated interface and strong interfacial adhesion with P(VDF-TrFE-CFE) polymer, which together contributed to a dramatic improvement in permittivity of composites. Typically, the dielectric constant of composite with 10 vol% rod-like TiO 2 reaches 160 at 100 Hz, in contrast to 102.5 for the composite with 10 vol% commercial TiO 2 and 47 for pristine P(VDF-TrFE-CFE). This study provides a solution for obtaining high-k dielectric composites with low dielectric loss, which is highly desired for advanced electronic devices.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Mingkun Zhang,Xianjun Tan,Wenhui Ding,Zhenying Jiang,Kai He,Bo Zhao,Haruka Takeuchi,Yuxiong Huang
The residual fluorion (F – ) generated during per- and polyfluoroalkyl substances (PFASs) treatment presents a new environmental burden, while minimum attention has been redirected to its removal. In this study, Al-based electrocoagulation (EC) technique was optimized to effectively remove the residual F – during PFASs wastewater treatment. At EC’s optimal operating conditions, it can achieve over 81.7 % removal efficiency within 30 min. Furthermore, EC exhibited a stable performance on removing F – across a wide range of pH (3–11), and could form stable flocs under neutral pH conditions. The in-depth characterization of flocs has revealed the dynamic change of Al-F species along the EC process, and removal mechanisms were proved to be a combination of complexation, ion exchange, hydrogen bonding and precipitation. In addition, the optimized EC showed stable removal efficiency of F – with the co-existence of multiple PFASs. Hence, we have effectively removed the residual F – during PFASs wastewater treatment, and provide new insights to better understand the defluorination mechanisms in the EC process.
研究领域:
环境科学
·
水处理工程
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Zhen Cao,Hao Li,Gregory V. Lowry,Xiaoyang Shi,Xiangcheng Pan,Xinhua Xu,Graeme Henkelman,Jiang Xu
Groundwater contamination by halogenated organic compounds, especially fluorinated ones, threatens freshwater sources globally. Sulfidized nanoscale zero-valent iron (SNZVI), which is demonstrably effective for dechlorination of groundwater contaminants, has not been well explored for defluorination. Here, we show that SNZVI nanoparticles synthesized via a modified post-sulfidation method provide rapid dechlorination (∼1100 μmol m–2 day–1) and relatively fast defluorination (∼6 μmol m–2 day–1) of a halogenated emerging contaminant (florfenicol) under ambient conditions, the fastest rates that have ever been reported for Fe0-based technologies. Batch reactivity experiments, material characterizations, and theoretical calculations indicate that coating S onto the metallic Fe surface provides a highly chemically reactive surface and changes the primary dechlorination pathway from atomic H for nanoscale zero-valent iron (NZVI) to electron transfer for SNZVI. S and Fe sites are responsible for the direct electron transfer and atomic H-mediated reaction, respectively, and β-elimination is the primary defluorination pathway. Notably, the Cl atoms in florfenicol make the surface more chemically reactive for defluorination, either by increasing florfenicol adsorption or by electronic effects. The defluorination rate by SNZVI is ∼132–222 times higher with chlorine attached compared to the absence of chlorine in the molecule. These mechanistic insights could lead to new SNZVI materials for in situ groundwater remediation of fluorinated contaminants.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Qiongqiong Luo,Jinshun Lei,Ziyu Zhuang,Dewen Zeng
The solubility data of the MgF2–MnF2–MnSO4–H2O quaternary system and its subsystems are crucial for the removal of magnesium ions from a MnSO4 aqueous solution as the MgF2 precipitate. However, these data recorded at 298.15 K have not been reported, except for the MnF2–MnSO4–H2O system. In this study, the solubility isotherms of the MgF2–MnF2–H2O, MgF2–MnSO4–H2O, and MgF2–MnF2–MnSO4–H2O systems at 298.15 K and MnF2 solubility in pure water at various temperatures were systematically measured. The results show that MgF2 solubility initially decreases sharply followed by a gradual decrease as the MnF2 concentration increases. MgF2 solubility rises with increasing MnSO4 concentration in pure MnSO4 and the MnF2-saturated MnSO4 aqueous solution. MgF2 solubility in the MnF2-saturated MnSO4 aqueous solution decreases to 2.3–6.5% of its value in the pure MnSO4 aqueous solution at a certain MnSO4 concentration. MnF2 solubility increases with increasing temperatures in the MnF2–H2O system. A Pitzer–Simonson–Clegg model incorporated in the ISLEC software was used to simulate and predict the solubility curves of the MgF2–MnF2–MnSO4–H2O quaternary system and its subsystems. The model satisfactorily represented the solubility data of the subbinary and subternary systems of the MgF2–MnF2–MnSO4–H2O quaternary system within the analysis error, except for the solubility isotherms of the Mg(Mn)SO4·7H2O, Mg(Mn)SO4·4H2O, and Mg(Mn)SO4·H2O solid solutions. The predicted solubility data of the MgF2–MnSO4–H2O system at 298.15 K agree well with the experimental data with a slight deviation of the MgF2–MnF2–MnSO4–H2O system. Based on the established model, the variation of MgF2 solubility curves with the addition of anhydrous MnF2 in MnSO4 aqueous solutions at different concentrations was predicted. The study provides theoretical guidance for removing magnesium ions from a MnSO4 aqueous solution via MgF2 precipitation.
研究领域:
化学工程
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2025
·
IF 9.8
Xinyue Yin,Shuran Yang,Guorong Du,Lu Zhang,Yuhong Xiang,Nengsheng Ye
The uncontrolled use of antibiotics poses a significant threat to human health and ecosystems. Accurate differentiation and trace detection of fluoroquinolone antibiotics (FQs) in foods are imperative. Fluorine–doped carbon quantum dots chelated with Al 3+ (FCQDs–Al 3+ ) was prepared to design a ratiometric fluorescence sensor for the detection of ciprofloxacin (CIP) in milk. The fluorescence of the FCQDs at 360 nm was quenched by CIP and enhanced at 430 nm by CIP chelation with Al 3+ . The limit of detection of the sensor was 4.20 nM, and the spiked recovery rates in milk samples were 96.32 %–100.07 %. Machine learning methods confirmed quenching mechanism caused by the F F interaction and established identification models of six FQs. Therefore, fluoroquinolone antibiotics detection can be conducted qualitatively first and then quantitatively. The developed sensor had excellent quantitative results for the other five FQs. The method demonstrated significant potential in the identification and detection of FQs.
研究领域:
分析化学
·
纳米技术
·
生物传感
·
食品安全
·
抗生素检测
·
材料科学
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机器学习应用
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2015
·Vol. 53
·期 8
·1023-1031
·
IF 3.113
Hua-Feng Fei,Xiyin Gao,Xiaojie Han,Qian Wang,Tao Hu,Zhijie Zhang,Zemin Xie
Novel fluorine containing siloxane monomer, namely, 4-trifluoromethylphenylmethyl cyclosiloxane ( PF3 ) and mixed cyclosiloxane including both 4-trifluoromethylphenylmethyl siloxane ( P ) unit and trifluoropropyl siloxane ( F ) unit were successfully synthesized in this study. Furthermore, their series including vinyl-terminated copolymers with different compositions were synthesized. The microstructures of copolymers were investigated by 1 H NMR, 29 Si NMR, 19 F NMR, Fourier transform infrared spectroscopy, and differential scanning calorimetry (DSC). The results of characterizations confirmed that the copolymers exhibited random microstructure. Moreover, the analysis of the result of DSC also revealed that the copolymers had a low glass transition temperature. The thermogravimetric analysis indicated that poly(4-trifluoromethylphenylmethyl)siloxane ( PPF3 ) exhibited higher thermal stability than conventional fluorosilicones rubber ( FSR ). The dynamic mechanical analysis showed that the damping factors of these copolymers were greater than 0.3 in a wide range of temperature. The mass swelling ratios were less than 5.5% when the samples were immersed in No. 3 jet fuel for a month. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53 , 1023–1031
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）