CATALYSIS COMMUNICATIONS
·
2020
·
IF 3.612
Jiaqin Lu,Wenfeng Han,Wei Yu,Yongnan Liu,Hong Yang,Bing Liu,Haodong Tang,Ying Li
Aluminum fluoride (AlF 3 ) is a typical catalyst for dehydrofluorination of hydrofluorocarbons (HFCs) to fluoroolefins with high heat of reaction. Consequently, heat supply and sintering are the key challenges for AlF 3 -based catalysts. Herein, SiC with high thermal conductivity and resistance to HF corrosion is suggested as a candidate support of AlF 3 catalyst. The interaction between AlF 3 and SiC leads to uniform distribution of the catalytic phase, and as a result of this, AlF 3 /SiC exhibits high catalytic activity and stability for the dehydrofluorination of 1,1-difluoroethane to vinyl fluoride. This study proposes a novel catalyst support (SiC) for strong endothermic catalytic reactions involving HFCs for the first time to the best of our knowledge.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
LIQUID CRYSTALS
·
2017
·
IF 2.661
Longyan Duan,Dingqian Shi,Pei Chen,Kun Hu,Liyuan Ren,Xinbing Chen,Zhongwei An
Series of laterally multifluorinated heterocyclic compounds, 2-(2ʹ,3-difluoro-4ʹ-alkoxy-1,1ʹ-biphenyl-4-yl)-benzoxazole derivatives (nPF(2)PF(3)Bx), are prepared and characterised. They mainly display enantiotropic nematic mesophases with wider mesophase ranges of 12–107°C (heating process) and 22–134°C (cooling process) than the corresponding analogues. The enhanced nematic mesophase stability is achieved via slightly increasing inter-ring twist angle with inter-ring lateral fluorine substitute in biphenyl unit, as well as through improving the molecular polarity with multifluorine substitutes. Meanwhile, two inter-ring lateral fluorine atoms lead to a decrease in melting/clearing points and a wide nematic mesophase range, which makes it possible for heterocyclic mesogens nPF(2)PF(3)Bx to use in nematic liquid crystal display mixtures.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Frontiers of Environmental Science & Engineering
·
2021
·Vol. 16
·期 8
·1-10
·
IF 4.357
Shen Zhichao,Zhan Lu,Xu Zhenming
Current study proposes a green regeneration method of activated carbon (AC) laden with Perfluorochemicals (PFCs) from the perspective of environmental safety and resource regeneration. The defluorination efficiencies of AC adsorbed perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanesulfonate (PFBS) using three molten sodium salts and one molten alkali were compared. Results showed that defluorination efficiencies of molten NaOH for the three PFCs were higher than the other three molten sodium salts at lower temperature. At 700°C, the defluorination efficiencies of PFOS and PFBS using molten NaOH reached to 84.2% and 79.2%, respectively, while the defluorination efficiency of PFOA was 35.3%. In addition, the temperature of molten salt, the holding time and the ratio of salt to carbon were directly proportional to the defluorination efficiency. The low defluorination efficiency of PFOA was due to the low thermal stability of PFOA, which made it difficult to be captured by molten salt. The weight loss range of PFOA was 75°C–125°C, which was much lower than PFOS and PFBS (400°C–500°C). From the perspective of gas production, fluorine-containing gases produced from molten NaOH-treated AC were significantly reduced, which means that environmental risks were significantly reduced. After molten NaOH treatment, the regenerated AC had higher adsorption capacity than that of pre-treated AC.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 96
·93539-93545
·
IF 3.289
Ye Zhu,Hai-Bo Zhang,Lian-Jun Ding,Zheng Chen,Da-Ye Sun,Zhen-Hua Jiang
Perfluorocarbon groups or related compounds are usually used to modify polymer materials because of their low surface energy properties. In this paper, a novel perfluorocarbon-containing compound was synthesized and used as a capping agent for the preparation of perfluorocarbon chain terminated poly(ether sulfone). The regulation of the fluorine content was achieved by controlling the molecular weight. FTIR and 1H NMR spectra were used to confirm the existence of perfluorocarbon terminated groups in the polymer chains. In addition, the ratios of F/C were acquired by integral area calculation from the 1H NMR spectrum. XPS characterization showed that the surface migration phenomenon of fluorine became apparent along with the increase of the F/C ratio. Further testing found that the introduction of perfluorinated end groups into the PES chains had little influence on the polymers' mechanical and thermal performance, by contrast, their surface energy decreased efficiently from approximately 40 mJ m−2 to 16 mJ m−2 with the F/C ratio on the surface increased from 0 to 0.556, which could develop PES as a low surface energy material for industrial applications.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Junchao Zhao,Yangyang Fu,Song Lu,Neng Tao,Zhitao Yin,Muhammad Usman Shahid,Heping Zhang
Perfluoro copolymers (PFCPs) with PFD (long chain -(CF 2 ) 7 CF 3 moiety) have a wide range of applications, such as hydrophobic and oleophobic modification of dry chemicals suppressants. However, high fluorine contents may produce much HF in thermal environments. In this study, a newly designed perfluoro copolymer (DPFCP) was synthesized and its application, pyrolysis and HF production were investigated. The pyrolysis of DPFCP could be divided into three stages, whereas the gas mainly released at the second stage, including CH 2 O, CO 2 , H 2 O, C x H y , C x H y F z , NH 3 , HF. A tube furnace was used to heating DPFCP to collect residual products and HF. The results indicated that HF was mainly produced under 370 °C.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2014
·
IF 2.129
Mingqiong Zhou,Jingdong Peng,Rongxing He,Yuting He,Jing Zhang,Aiping Li
A reliable and versatile high performance liquid chromatography coupled with resonance Rayleigh scattering method was established for the determination of three fluoroquinolones, including levofloxacin , norfloxacin and enrofloxacin in water sample and human urine sample. In pH 4.4–4.6 Britton–Robinson buffer medium, the fluoroquinolones separated by high performance liquid chromatography could react with erythrosine to form 1:1 ion-association complexes, which could make contributions to the great enhancement of RRS. The resonance Rayleigh scattering signal was recorded at λ ex = λ em = 330 nm. The resonance Rayleigh scattering spectral characteristics of the drugs and the experimental conditions such as pH, detection wavelength, erythrosine concentration, flow rate , the length of reaction tube were studied. Quantum chemistry calculation, Fourier transform infrared spectroscopy and absorption spectroscopy were used to discuss the reaction mechanism. The recoveries of samples added standard ranged from 97.53% to 102.00%, and the relative standard deviation was below 4.64%. The limit of detection (S/N = 3) of 0.05–0.12 μg mL −1 was reached, and the linear regression coefficients were all above 0.999. The proposed method was proved as a simple, low cost and high sensitivity method.
研究领域:
分析化学
·
药物分析
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2022
·
IF 4.601
Yanyan Wang,Liuqian Bao,Jiajing Sun,Yuanyuan Ding,Jiasheng Shi,Zhengyu Duan,Zhiyong Chen
Fluorous affinity chromatography has received growing attention in separation and purification of fluoro compounds, but the wettability of the fluorinated stationary phases is seldom noticed. Here, we construct a series of micro-sized fluorine-containing microspheres by solvothermal precipitation polymerization. The fluorinated microspheres could be obtained with narrow size distribution at even high monomer loading of 15 wt%. Through alternating fluoro monomer, both the particle size and the wettability of the microsphere array could be tuned. Among them, the poly(divinylbenzene -dodecafluoroheptyl methacrylate), P(DVB-DFHMA), microsphere (6.1 μm) arrays displays superhydrophobicity with 153.2° water contact angle. The P(DVB-DFHMA) fluorinated microspheres (7.58% fluorine content) can be packed into steel-less columns as stationary phase for high-performance liquid chromatography. The retention mechanism of the fluorinated column is proven to be the specific fluorine-fluorine interaction. Compared to the commercial C18 silica column, the fluorinated column can completely separate fluorine-containing compounds under high water content mobile phase, including small fluoro molecules and fluoro macromolecules, at much lower back pressure by fluorous affinity.
研究领域:
化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
·
2025
·
IF 2.8
Shi Si,Zhang Zijie,Wang Rong,Xue Shiji,Fei Wanyu,Peng Yue’e
In this study, a detailed analysis of 20 per- and polyfluoroalkyl substances (PFAS), including 13 perfluorocarboxylic acids (PFCAs) (C4–C18), four perfluorosulfonic acids (PFSAs) (C4, C6, C8, C10), and three polyfluoroalkyl substances, in different environmental media of Fu River, which was the main sewage storage body, and located near the Tianhe Airport in Wuhan, China. In the surface water samples, short-chain PFAS, perfluorobutanesulfonic acid (PFBS) and perfluorobutanoic acid (PFBA) were the most prevalent, and highest concentrations of 168 ng/L and 49.7 ng/L, respectively. However, in the sediment samples, PFBS and perfluorooctane sulfonate (PFOS) were the most prevalent, and highest concentrations of 840 ng/kg and 1510 ng/kg, respectively. Meanwhile, PFOS was the most prevalent substance, with the highest concentrations measured at 23.3 μg/kg in egg yolk and 28.1 μg/kg in fish, accounting for proportions of 82% and 88%, respectively. Two new short-chain substitutes of PFOS, 6:2 clorinated polyfluoroalykyl ether sulfonate (6:2 Cl-PFESA) and 8:2 clorinated polyfluoroalykyl ether sulfonate (8:2 Cl-PFESA), emerged in sediment and fish. The PFAS in eggs, fish, and vegetables of Fu River Basin poses a potential health risk to residents according to the suggested value of the European Food Safety Agency.
研究领域:
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Yu Chen,Huan Chen,Haihua Wang,Xia Xin,Wenbing Kang
Silver nanoclusters (NCs) possess precise and tunable structures characterized by their unique properties, yet a single component often underperforms in practical applications. In this work, a series of stable and highly effective antibacterial gels were prepared by incorporating fluoropolymer (perfluoro-2, 5-dimethyl-3, 6-dioxactyl glycol acrylate-co-acrylic acid, FAA) into aqueous solutions of (NH 4 ) 6 [Ag 6 (mna) 6 ] (Ag 6 -NCs). It can be quickly gelated within a few seconds to achieve the rapid transformation of one-dimensional into three-dimensional structures. These gels are formed through the layering of nanowires, and their mechanical properties can be tailored by adjusting the FAA concentration. The assembly process of Ag 6 -NCs/FAA hydrogels was investigated by comparing it with various poly carboxylic acids, neutralized FAA, and aqueous AgNO 3 solutions under identical experimental conditions. This assembly results from various interactions, including hydrophobic interactions, van der Waals forces and hydrogen bonds. Furthermore, the hydrogel system demonstrated improved antibacterial activity due to the presence of Ag ions and fluorine atoms. The functional composite of materials, achieved through heterogeneous assembly, promoted the design of metal NC materials and furthered the development of macro manufacturing technology.
研究领域:
材料科学
·
生物学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Heliyon
·
2024
·
IF 3.4
Chenhan Lv,Haixiang Cheng,Rui Fan,Jingyu Sun,Xinghai Liu,Yinghui Ji
Organic fluorine compounds are acute carcinogenic and mutagenic to humans. Photoelectrocatalysis (PEC) treatment is an innovative technology in the field of the removal of fluorine compounds, and thus current research focused on improving stability and catalytic ability of photoanode. In this study, it has been synthesized a rGO/BiOI photocathode for the efficient degradation of 4-Fluoroaniline (4-FA). The physical characterization and photoelectrochemical properties of the photocathode was determined. The results indicate that the PEC treatment with the rGO/BiOI photocathode was more efficient compared with individual processes. During the optimization experiments, the PEC treatment achieved 99.58 % and 72.12 % of 4-FA degradation and defluorination within 1 h. Cyclic stability experiments show that rGO/BiOI photocathode was efficient and stable, which reached 96.91 % and 67.64 % of 4-FA degradation and defluorination after five cycles. Mechanism analysis indicates that the PEC process was based on an electrochemical reaction and photo-induced processes. The degradation product of 4-FA was mainly 2,4-di-t-butylphenol, and trapping experiments indicates that h + is the primary oxidizing species. Therefore, PEC treatment with rGO/BiOI photocathode is a competitive green approach to remove fluorine compounds pollutants and brings new insights into development of PEC treatment.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2023
·
IF 3.3
Dan Chen,Yanling Jin,Wenxuan Zhu,Qingqing Huang,Yaping Li,Minfeng Lü
Three new fluoride phosphates and fluorophosphates, Ba 3 Fe(PO 4 )F 6 , Ba 3 Ga(PO 3.5 F 0.5 )O 0.5 F 5.5 and Ba 3 Fe(PO 3 F)F 7 , have been synthesized through fluoride-rich hydrothermal reactions . Isostructural Ba 3 Fe(PO 4 )F 6 and Ba 3 Ga(PO 3.5 F 0.5 )O 0.5 F 5.5 revealed a three-dimensional structure comprised of [M(PO 4-x )F 4 ] 4−x chains and two-dimensional [Ba 3 F 2-x O x ] 4+x layers [M = Fe,Ga; x = 0,0.5], while Ba 3 Fe(PO 3 F)F 7 contained distorted two-dimensional [Ba 3 F 2 ] 4+ layers and [Fe(PO 3 F)F 5 ] 4- dimers. Two-dimensional [Ba 3 F 2 ] 4+ layers are formed by fluorine-centred tetrahedra. Close examinations of bond length and bond strength in fluorine-centred tetrahedron complexes suggested that fluorine-centred tetrahedra are indeed reasonable structural subunits.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Yihua Chen,Hang Ma,Jiaxin Zhu,Yurong Gu,Tongzhou Liu
UV/Fe 3+ -facilitated PFOA defluorination was often reported and recognized to proceed through a “ligand-to-metal charge transfer (LMCT)” mechanism in the literatures. Sufficient Fe 3+ supply is important for sustaining the LMCT reaction pathway. In this study, an interesting “excessive defluorination” was observed, even the continuous Fe 3+ supply was cut off, implying a parallel mechanism strengthening PFOA defluorination . Based the results of intermediate products detection, 19 F NMR analysis, and exploration of electron density alternation, transition energy evolution, and bonds characteristics, remarkable electron density perturbation in [PFOA-Fe] 2+ was revealed. This effect was triggered by the complexation between PFOA anion and Fe 3+ , diminishing electron shielding on the perfluorinated carbon chain. Hence, the dissociation energy of C–C bonds was reduced by maximally 53% (C4-C5). Once attacked by high-flux UV 254 photons, the perfluorinated carbon chain underwent scission , and subsequent defluorination was achieved via hydrolysis reactions. This parallel mechanism cooperated with the LMCT mechanism, leading to the observed “excessive defluorination.” The degree of UV/Fe 3+ -synergized PFOA defluorination depended on UV 254 photon flux and Fe 3+ dosage. High UV 254 intensity guaranteed fast defluorination kinetics. A [Fe 3+ ]/[PFOA] molar ratio near 1 showed the best UV/Fe 3+ synergic effect on PFOA defluorination.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）