JOURNAL OF CHEMICAL THERMODYNAMICS
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2020
·
IF 2.888
Jinyi Chen,Hongxing Wang
Density and viscosity data of pure 3-chloro-4-fluoronitrobenzene and 3-chloro-2-fluoronitrobenzene were obtained in temperature range from 318.15 K to 348.15 K at the local atmospheric pressure of 99.7 kPa. The value of corresponding saturated vapour pressure of two isomers were determined in the temperature range of 409 K to 517 K. The relationship between temperature and density can be well correlated by the linear equation. The viscosity data was well described by the Litovitz, Ghatee, VFT, and Andrade equations, and the calculated value by the VFT equation is consistent with the measured data. Both the Antoine and Riedel equations can accurately describe the relationship between saturated vapour pressure and temperature of 3-chloro-4-fluoronitrobenzene and 3-chloro-2-fluoronitrobenzene, which can meet the requirements for chemical design. In addition, the thermal expansion coefficient was determined based on the density data, and the molar vaporisation enthalpy of two isomers was evaluated using the Clausius-Clapeyron equation.
研究领域:
化学工程
·
物理化学
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DOI
高影响因子
JOURNAL OF CATALYSIS
·
2017
·
IF 6.844
Tingting Hou,Yehong Wang,Jian Zhang,Mingrun Li,Jianmin Lu,Marc Heggen,Carsten Sievers,Feng Wang
In many catalytic processes, metastable reaction intermediates are more valuable and desirable than final products. Here, we report Ni–Ni δ+ clusters on ceria where the extent of reduction of nickel oxide/ceria in H 2 has been optimized. This catalyst shows high selectivity in reducing nitrobenzene to azoxybenzene, the latter usually being metastable. Due to strong electronic metal–support interactions between Ni and ceria, mixed Ni–Ni δ+ clusters are formed on ceria even after reduction at 500 °C in hydrogen. The Ni–Ni δ+ clusters are highly dispersed on ceria, as observed by high-angle annular dark-field scanning–transmission electron microscopy and energy-dispersive X-ray spectroscopy element mapping. This structural uniqueness is clearly reflected in the inhibition of azoxybenzene hydrogenation to aniline, and therefore the catalyst shows high azoxybenzene selectivity (92%). In comparison, the Ni metal catalyst mostly gives aniline and the NiO catalyst has low activity. This study shows how to steer catalytic reactions toward metastable intermediate products by tuning the extent of reduction of metal oxides deposited on reducible oxides.
研究领域:
化学
·
催化科学
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DOI
高影响因子
LIQUID CRYSTALS
·
2016
·
IF 2.244
Dingqian Shi,Kun Hu,Pei Chen,Weisong Du,Aiai Gao,Ran Chen,Xinbing Chen,Zhongwei An
A series of nematic heterocyclic liquid crystals, 2-(2ʹ-fluoro-4ʹ-alkoxy-1,1ʹ-biphenyl-4-yl)-benzoxazole derivatives (coded as nPF(2)PBx) bearing hydrogen (nPF(2)PBH), methyl (nPF(2)PBM) and nitro (nPF(2)PBN) terminal groups, respectively, are developped and investigated. The results show that the nematic mesophase stability is obviously improved via a slightly increase in the inter-ring twist angle between the planes of two phenyl rings in the biphenyl unit, where modification of the twist angle can be achieved by adjusting the position of the lateral monofluorine substituent from the outer to the inter ring of the biphenyl mesogenic core unit. Meanwhile, the inter-ring lateral fluorine substituent results in a decrease in both melting and clearing points but only a nematic mesophase with an acceptably wide mesophase range for nPF(2)PBx, and thus a potential application in liquid crystal display mixtures is expected, especially for the compounds nPF(2)PBM and nPF(2)PBN. The reduced π–π interaction/conjugation caused by the increased twist angle is considered as one of the possible reasons for the formation of a nematic mesophase.
研究领域:
材料科学
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液晶化学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
·
IF 7.312
Haijun Wu,DuiDui Wang,Puyang Zhou,Meng Xie,JunJie Jing,Yuanguo Xu,Jimin Xie
Construction of visible light-response photocatalyst with enhanced photoelectric properties is considered to be an effective method for treating environmental pollutants under visible light irradiation. Herein, a novel PANI/Zn 3 In 2 S 6 composite photocatalyst was successfully synthesized by the method of electrostatic adsorption. The 0.05% Polyaniline/Zn 3 In 2 S 6 (PANI/Zn 3 In 2 S 6 ) demonstrates superior photocatalytic Cr(VI) reduction and 2-Mercaptobenzothiazole (MBT) degradation performance under visible light (λ ≥ 420 nm), which is 3.76 and 3.27 times to that of Zn 3 In 2 S 6 , respectively. The improvement of photocatalytic performance is attributed to the modification the Zn 3 In 2 S 6 by PANI to maximize the carrier migration rate, light absorption intensity and cycle stability of the pure Zn 3 In 2 S 6 , so as to obtain efficient and stable photocatalytic performance. The tests of mass spectrometry analysis (MS) was conducted to detect intermediate products during MBT degradation, and a possible photodegradation pathway was proposed. Moreover, under the long-wavelength sunlight (λ ≥ 550 nm), it still shows improved photoreduction of Cr(VI) performance, the reaction rate constant is 2.18 times that of Zn 3 In 2 S 6 . Finally, by the band structure and capture experiments, a possible reaction mechanism over PANI/Zn 3 In 2 S 6 was proposed. This work provides a way to deal with heavy metal ion pollution in a long wavelength condition.
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
Reaction Chemistry & Engineering
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2022
·Vol. 7
·期 6
·1447-1460
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IF 5.2
Jianchao Liu,Hong Xu,Jinxiang Dong,Ligong Zhou,Xuekuan Li,Hui Ge
The synthesis of alkylbenzenes produced from syngas and benzene over a ZnCrOx/beta bifunctional catalyst has been studied. Our characterization results showed that in the mixed catalyst the beta-zeolite crystallites were dispersed on the surface of the ZnCr oxides. The close contact facilitated the methanol intermediate formed on ZnCrOx to diffuse to the acidic sites of the beta-zeolite crystallites, reacting with benzene to produce alkylbenzenes. The competitive side reactions, which lead to by-products such as CO2 and hydrocarbons, were suppressed. The medium strong acidity and mesopores of the beta-zeolite crystallites contributed to the high activity and selectivity. The optimized ZnCrOx/beta-11 = 1 : 3 (w/w) afforded 40.72% benzene and 62.40% CO conversion with high alkylbenzene selectivity during the initial stage of the reaction, which then underwent quick deactivation, and maintained a benzene conversion of ∼27%. Coke formation on the beta-zeolite crystallites was proposed to be the main cause of deactivation.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
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IF 8.097
Ningwei Sun,Kaixin Su,Ziwei Zhou,Ye Yu,Xuzhou Tian,Daming Wang,Xiaogang Zhao,Hongwei Zhou,Chunhai Chen
Electrofluorochromism has attracted great attention due to the intelligence optoelectronic and sensing applications. The intrinsically switchable fluorophores with high solid-state fluorescence are regarded as key for ideal electrofluorochromic materials. Here, we reported an AIE-active polyamide with diphenylamine and tetraphenylethylene units, showing high fluorescence quantum yield up to 69.1% for the solid polymer film and stable electrochemical cycling stability. The polyamide exhibited reversible color and emission switching even in hundreds of cycles, and the fluorescence on/off contrast ratio was determined up to 417, which is the highest value to our knowledge. Furthermore, as the response time is vital for the real-life applications, to speed up the response of electrofluorochromism, a porous polymer film was readily prepared through a facile method, notably exhibiting high fluorescence contrast, long-term stability and obviously improved response, due to the sharply increased surface area. Therefore, the AIE-functionalization combining the porous structure strategy will synergistically and dramatically improve the electrofluorochromic performance, which will also promote their practical applications in the near future.
研究领域:
材料科学
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光学
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DOI
PubMed
高影响因子
Polymers
·
2017
·Vol. 10
·期 1
·23
·
IF 3.364
Yan Zhang,Lingqian Kong,Xiuping Ju,Jinsheng Zhao
Two new donor–acceptor type electrochromic copolymers containing non-fluorinated and di-fluorinated benzothiadiazole analogues, namely P(TBT-TBTh) and P(TBT-F-TBTh), were synthesized successfully through chemical polymerization. Both polymers were measured by cyclic voltammetry, UV-vis spectroscopy, colorimetry and thermogravimetric analysis to study the influence of fluoro substitution on the electrochromic performance. The results demonstrated that the two polymer films displayed well-defined redox peaks in pairs during the p-type doping, and showed distinct color change from dark gray blue to light green for P(TBT-TBTh) with the band gap of 1.51 eV, and from gray blue to celandine green for P(TBT-F-TBTh) with the band gap of 1.58 eV. P(TBT-F-TBTh) presented lower highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels, and better stability than P(TBT-TBTh). It was found that the two fluorine atoms participated in not only inductive effects but also mesomeric effects in the P(TBT-F-TBTh) backbone. In addition, the polymers exhibited high optical contrasts, short response time, and favorable coloration efficiency, especially in the near infrared region. The characterization results indicated that the two reported polymers can be the potential choice as electrochromic materials.Keywords:electrochromism;donor–acceptor type polymers;benzotriazole;benzothiadiazole;fluorination
研究领域:
材料科学
·
化学
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DOI
PubMed
高影响因子
APPLIED BIOCHEMISTRY AND MICROBIOLOGY
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2022
·Vol. 58
·期 6
·796-805
·
IF 1.065
Li P.,Jiang Y.,Fei Y. Y.,Zeng X. C.
Abstract Benzo(a)pyrene (BaP) is one of the most common organic pollutants in the environment, and its microbial removal has great ecological and economic value. Here, using BaP (50 mg/L) as the sole carbon source, dynamic changes in camel rumen and gut bacterial communities were analyzed by high-throughput sequencing. Next, cultivable BaP-degrading isolates were obtained, and their degradation characteristics were explored. The relative abundance of most bacteria in the gut and rumen underwent apparent changes after BaP treatment. The rumen and gut bacteria have the ability to degrade BaP but fluctuated during iterative culturing from the first to the fifth generation of gut communities displaying the highest BaP degradation efficiency (BDE) (74.4 and 81.1%, respectively). Moreover, 37 isolates exhibiting BDE were identified. Among these isolates, CL9 ( Klebsiella sp.), CL16 ( Ochrobactrum sp.), CC6 ( Ochrobactrum sp.), and CC16 ( Bacillus sp.) showed BDEs of up to 70.8, 69.3, 68.4, and 76.2%, respectively. The enzyme catechol-2,3-dioxygenase was involved in BaP degradation in these four BaP-degrading isolates and represented the main BaP degradation pathway in isolates CL9 and CL16; however, the relative expression level of the gene phnAc was higher in isolates CC6 and CC16 than in isolates CL9 and CL16. Our results provided promising bacterial resources for the removal of BaP and laid the foundation for the application of animal gastrointestinal bacteria to degrade environmental pollutants.
研究领域:
环境微生物学
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动物科学
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生物修复
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DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Ren Ma,Yujing Zhang,Feiyang Yu,Shilong Wei,Yang Xing,Chengfang Qiao,Zhengqiang Xia,Qi Yang,Gang Xie,Sanping Chen
High energy level difference between electron donor (D) and electron acceptor (A) and low energy loss during charge transfer are prerequisites for the construction of efficient D–A-type covalent-organic framework (COF) photocatalysts. However, the spatial structure characteristics of the building blocks inevitably lead to the torsion of the D–A COF skeleton during the construction process and thus prevent effective charge migration. Herein, with the high-energy-level triphenylamine (TPA) as a model electron donor, the formyl positional isomers of tris(3-formylbiphenyl) amine (NDC) and tri(4-formylbiphenyl) amine (NBC) react with an acceptor 1,3,5-tris(4-aminophenyl) triazine (TTA), producing both D–A COFs for photocatalytic CO2 reduction and benzylamine coupling reactions. Structural investigations evidence that the formyl positional isomerism imparts the dihedral angle of TPA single arm reducing from 51.09 to 2.12°, the interlayer spacing from 3.89 to 3.55 Å, and the exciton binding energy from 97.25 to 85.86 meV in TTA-COFs. Such the “near-flat” TTA-NDC structure with confined clover-like channels dramatically accelerates the intralayer and interlayer charge migration efficiency and improves CO2 adsorption and oxygen activation ability (O2•– concentration of 48.01 μmol·L–1 in 3 h). To the best of our knowledge, TTA-NDC exhibits the highest benzylamine coupling efficiency with a turnover frequency value of 518.4 h–1 among the pristine COF photocatalysts, and its electron consumption rate for photocatalytic CO2 reduction reaches 1632.2 μmol·g–1·h–1, 3.85-fold higher than TTA-NBC, far surpassing most COF-based photocatalysts. Parallelly, the protonated H-TTA-NDC shows high CO2 reduction to CH4 yield (310.1 μmol·g–1·h–1) and selectivity (85.1%) due to the improved proton conductivity (σ = 1.07 × 10–2 S·cm–1). Additionally, the durability, stability, and possible photocatalytic mechanisms of TTA-NDC were systematically investigated.
研究领域:
材料科学
·
光化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 19
·e202400538
·
IF 1.9
Anna Zhou,Zhe Li,Dan Li,Chunni Cheng,Xiang Chen,Qunfang Wang,Alice A. Kasera,Jianhui Li,Qiong Hou,Ronghua Zeng
Graphical The triphenylamine (TPA) with high discharge plateau and benzoquinone (BQ) with high theoretical capacity are used to synthesize the polymer (poly triphenylamine-benzoquinone (PTPA-BQ)) as cathode for lithium ion batteries, which can enhance the discharge plateau and effectively inhibit the dissolution of BQ small molecules simultaneously. Benzoquinone (BQ) electrode is regarded as next generation energy storage material for lithium ion batteries (LIBs) because of its advantages of high theoretical specific capacity, abundant source, environmental friendliness. However, the two key challenges, the dissolution of BQ in organic electrolyte and the low discharge plateaus, impede practical application of BQ as cathode. Here, triphenylamine (TPA) with high working voltage and BQ with high theoretical capacity are used to synthesize triphenylamine-benzoquinone monomer (TPA-BQ) and its polymer (poly triphenylamine-benzoquinone (PTPA-BQ)) as cathodes for LIBs. The charge/discharge results reveal that the discharge plateaus of TPA-BQ and PTPA-BQ increase from ~2.5 V to ~3.5 V, and PTPA-BQ exhibits high discharge capacity and remarkable cyclic stability compared with TPA-BQ. The electrochemical mechanism shows that the redox peak potential of ~2.3 V/~2.2 V are assigned to the insertion/extraction of lithium ion in C=O groups of BQ, while at high potential of ~3.6 V/~3.5 V corresponds to the de-dope/dope of the PF 6 − anion in TPA unit. The results demonstrate TPA was introduced BQ into small molecule to form PTPA-BQ polymer that can improve discharge plateaus and charge/discharge performance of BQ small molecule, which provide guides for solving the dissolution and discharge platforms of the other organic electrode materials.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2020
·
IF 4.049
Pengfei Li,Yanke Lu,Jiangxue Cao,Mengyuan Li,Chunliu Yang,Hongyuan Yan
An imidazolium ionic-liquid-modified phenolic resin (ILPR) was synthesized using 3-aminophenol as a functional monomer, glyoxylic acid as a green cross-linker, and polyethylene glycol 6000 as a porogen. The obtained ILPR showed better extraction of benzoylurea plant hormones thidiazuron and forchlorfenuron than the unmodified phenolic resin because the imidazolium IL provides more interaction modes with the analytes. ILPR, as a tailored adsorbent for solid-phase extraction, was coupled with high-performance liquid chromatography (ILPR‒SPE‒HPLC) for the simultaneous determination of thidiazuron and forchlorfenuron in cucumbers. Good linearity of the ILPR‒SPE‒HPLC method was obtained, ranging from 0.0100 to 5.00 μg g −1 with a correlation coefficient ( r ) ≥ 0.9999. The recoveries of spiked samples ranged from 91.4% to 100.7% with a relative standard deviation of ≤ 6.0%.
研究领域:
分析化学
·
食品科学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Jin Feng,Qiang Wang,Dongliang Fan,Lirong Ma,Deli Jiang,Jimin Xie,Jianjun Zhu
In order to investigate the roles of three-dimensional network structure and calcium on Ni catalysts, the Ni, Ni-Al 2 O 3 , Ni-Ca-Al 2 O 3 xerogel catalysts were successfully synthesized via the fast sol-gel process and chemical reduction method. The crystal structure of three different catalysts was observed with X-ray powder diffraction (XRD). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and nitrogen adsorption-desorption were employed to investigate the role of network structure of xerogel catalysts and the size distribution of Ni nanoparticles. The catalyst composition was determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) measurement and energy-dispersive X-ray spectroscopy (EDS). Temperature-programmed reduction (TPR) experiments were carried out to investigate the reducibility of nickel species and the interaction between nickel species and alumina. The catalytic hydrogenation of p -nitrophenol to p -aminophenol was investigated over the prepared nickel-based xerogel catalysts. The conversion of p -nitrophenol was monitored by UV spectrophotometry and high performance liquid chromatography (HPLC). The results show that the catalysts are highly selective for the conversion of p -nitrophenol to p -aminophenol and the order of catalytic activities of the catalysts is Ni < Ni-Al 2 O 3 < Ni-Ca-Al 2 O 3 . The catalysts were recycled and were used to evaluate the reutilization.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）