PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2018
·Vol. 20
·期 18
·12808-12816
·
IF 3.906
Zhiyong Li,Xiaoqing Yuan,Ying Feng,Yongkui Chen,Yuling Zhao,Huiyong Wang,Qingli Xu,Jianji Wang
Photo-induced conductivity modulation of stimuli-responsive materials is of great importance from the viewpoint of fundamental research and technology. In this work, 5 new kinds of azobenzene-based photo-responsive ionic liquids were synthesized and characterized, and UV/vis light modulation of their conductivity was investigated in an aqueous solution. The factors affecting the conductivity modulation of the photo-responsive fluids, such as photo-isomerization efficiency, photo-regulation aggregation, concentration and chemical structure of the ionic liquids, were examined systematically. It was found that the conductivity of the ionic liquids in water exhibited a significant increase upon UV light irradiation and the ionic liquids with a shorter alkyl spacer in the cation showed a more remarkable photo-induced conductivity enhancement with a maximum increase of 150%. In addition, the solution conductivity was restored (or very close) to the initial value upon an alternative irradiation with visible light. Thus, the solution conductivity can be modulated using alternative irradiation with UV and visible light. Although the reversible photo-isomerization of the azobenzene group under UV/vis irradiation is the origin of the conductivity modulation, the photo-regulated aggregation of the ionic liquid in water is indispensable for the maximum degree of conductivity modulation because UV irradiation can weaken, even break the aggregated cis-isomers of the ionic liquids in an aqueous solution.
研究领域:
材料科学
·
化学
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DOI
PubMed
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2024
·Vol. 40
·期 2
·279-286
·
IF 3.1
Dou Renju,Wang Qin,Ren Xiaoyan,Lu Lehui
Here we employ in-situ UV-Vis spectroscopy to monitor the sulfur redox reaction with oxygen-containing molecules as an additive, for example, biphenyl-4,4′-dicarboxylic acid (BDC). Furthermore, Raman spectrum, electron paramagnetic resonance (EPR), and electrospray ionization-mass spectrometry (ESI-MS) measurements reveal that the formation of BDC-S
•‒ 3
complexes can establish the long-term stability of polysulfide radicals, change the kinetics of sulfur redox reaction, and then generate decent capacity retention and rate capability. According to the density functional theory (DFT) analysis, S
•‒ 3
radicals are the underlying product of S
2‒ 6
cleavage, owing to the decreased chemical energy and the increased stability of S
•‒ 3
radicals through Lewis acid-base interaction. The assembled Li-S batteries with BDC additive deliver a high reversible capacity of 420 mA·h·g −1 over 200 cycles with over 98% Coulombic efficiency, under the current density of 0.2 C.
研究领域:
材料科学
·
电化学
·
理论化学
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DOI
高影响因子
Analytical Methods
·
2015
·Vol. 7
·期 13
·5447-5453
·
IF 1.821
Haiqian Zhao,Jihui Gao,Wei Zhou,Zhonghua Wang,Shaohua Wu
The reason for the prominent error in the hydroxyl radical detection method by UV-vis spectrophotometry with fast blue BB salt (FBBs) as the chromogenic agent was detected, and a modified method was proposed. The simultaneous extraction of FBBs in the diazosulfone extraction process was proven to have a distinct influence on the test results. In the modified method, FeSO4 was adopted to limit the extraction of FBBs by a toluene/butanol extraction agent, which sharply decreased the influence of FBBs on diazosulfone detection. The FBBs amount and extraction time played an important role in its extraction. The appropriate FBBs/MSIA ratio was 50, and the reasonable extraction time was 300 s for the modified method. ˙OH concentration in the directional decomposition of the Fenton system was detected. The test error was about 7%. This method is quite significant to test ˙OH quantificationally to better understand Fenton reaction mechanisms and promote the generation of ˙OH.
研究领域:
环境科学
·
分析化学
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DOI
高影响因子
FOOD CHEMISTRY
·
2016
·
IF 4.052
Shuang Zang,Sizhu Tian,Jia Jiang,Dandan Han,Xinyu Yu,Kun Wang,Dan Li,Dayong Lu,Aimin Yu,Ziwei Zhang
Twenty-one kinds of fruits including strawberry, mulberry, lemon, banana, etc. were measured for antioxidant capacity based on their ability to scavenge 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. Vitamin C equivalent antioxidant capacity (VCEAC) was used to quantify antioxidant capacity of the studied fruits. The results were expressed as mg of ascorbic acid equivalent per 100 g fruit. Each fruit was divided into two parts: harvest part (fresh fruit analyzed immediately), and liquid nitrogen frozen part (fruit frozen and pulverized in liquid nitrogen). Antioxidant capacities of both fresh and frozen fruits were determined, and VCEAC values were proved to have no significant difference. For the frozen fruits, the antioxidant capacities were measured by electron spin resonance spectroscopy (ESR) and UV–vis spectrometry. VCEAC values obtained with UV–vis and ESR range from 11.48 to 345.75 mg/100 g and 7.01 to 366.26 mg/100 g. Experimental results indicated that VCEAC values obtained by two methods were highly correlated.
研究领域:
食品科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2019
·
IF 2.931
Lijuan Huang,Xin Zhang,Zhuoyong Zhang
Many endogenous peptides are circulating in bodily fluids at micromole level, and accurate analysis of endogenous peptides at such low level is important. In this study, we presented an extensible, facile and sensitive sensor array based on UV–Vis spectroscopy of the AuNPs combined with chemometric methods for quantitative analysis of binary peptide mixture (Gly-Gly/Ala-Gln) using UV–Vis spectroscopy. High concentration arginine (Arg) and Cr 3+ can induce aggregation of the AuNPs and DNA-AuNPs. However, the glycylglycine (Gly-Gly) and alanyl-glutamine (Ala-Gln) can prevent the AuNPs from aggregation. We investigated the prevention of AuNPs aggregation by using Gly-Gly and Ala-Gln mixtures and constructed sensor arrays for quantitative analyses of Gly-Gly and Ala-Gln mixtures. The color change of the solution is relevant to the dose of the target, and it can be visualized by the naked eyes or monitored by UV–Vis spectrometry. Results showed that the concentrations of Arg and Cr 3+ are the key factors affecting the sensitivity of the sensor array. Whereas when Gly-Gly and Ala-Gln have to be analyzed simultaneously, concentrations of Arg and Cr 3+ both for Gly-Gly and Ala-Gln are difficult to be optimized. Taking the advantages of multivariate analysis and data fusion, PLS models and backward interval PLS (BiPLS) models were built for fused dataset constructed by UV–Vis data obtained at different concentrations of Arg and Cr 3+ . The best results were obtained from the PLS models. The proposed method can be extended to analysis of other peptides in more complex mixture systems.
研究领域:
分析化学
·
生物医学工程
·
光谱学
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DOI
PubMed
高影响因子
Drug Research
·
2023
·Vol. 73
·期 06
·335-340
·
IF 2.2
Guo Haihua,Zhang Rui,Deng Liangjun,Li Meng,Li Sha,Zhao Suqing
Background Inhalation preparation involves liquid or solid raw materials for delivering to lungs as aerosol or vapor. The liquid preparation for nebulizer is effective for convenient use and patient compliance and it has been extensively used in the treatment of clinical lung diseases. Clinical staff often mixes the compound ipratropium bromide with beclomethasone propionate and budesonide inhaler but reference values of inhalants for clinical use need to be established for simplifying the operation procedure. The high-performance liquid chromatography (HPLC) method of compound ipratropium bromide solution, beclomethasone propionate suspension and budesonide suspension after mixed atomization was studied. Methods The specificity, linearity, recovery (accuracy), precision and stability of compound ipratropium bromide, beclomethasone propionate and budesonide were tested to verify the developed liquid phase method. Results The developed liquid phase method had high specificity, linear R2≥0,999, recovery (accuracy) RSD (relative standard deviation) less than 2%, precision RSD less than 2,0%, and stability RSD less than 2,0%. Conclusion The liquid phase methodology developed in this study can be used for the determination of compound ipratropium bromide mixed with beclomethasone propionate and budesonide. The current methodology can also be used to provide a reference for the determination of its content after mixing, and further data support for its clinical medication.
研究领域:
药物分析
·
色谱学
·
药学
·
临床药理学
·
分析化学
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DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 51
·32146-32154
·
IF 3.108
Chengkai Pang,Yuqun Zhuo,Qiyu Weng
A series of Mn-exchanged SAPO-34 catalysts were synthesized and developed as catalysts for the low temperature selective catalytic reduction (SCR) of NO with ammonia in the presence of excess oxygen. 4Mn/SAPO-34 showed the highest SCR activity in the temperature range of 120–210 °C. The microstructure of zeolite supports, acidity, manganese species and reaction mechanism were investigated in detail by BET, NH3-TPD, UV-Vis, H2-TPR, XPS and in situ DRIFTS. Mn3+ and Mn4+ related species were proved to be the active sites for the SCR reaction. The Eley–Rideal mechanism was proved to be effective on 4Mn/SAPO-34 for the low temperature SCR reaction in which coordinated NH4+ species react with gas-phase NO to form an activated transition state and subsequently decomposed to N2 and H2O.
研究领域:
环境科学
·
催化化学
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DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2025
·
IF 3.1
Zhang Hongmei,Yang Yunxia,Wang Yanqing
Sudan dyes are recognized as carcinogens, which are strictly determined whether there are them in food for food safety. Hence, in order to understand the mechanism at the molecular level, this work investigated the binding interactions of Sudan I-IV with calfthy mus DNA. The synchronous fluorescence and UV–vis spectral results suggested the complex formation between Sudan I-IV and ct-DNA. EB and Hoechst 33258 displacement experimental results confirmed the binding sites of Sudan I-IV in ct-DNA and the minor groove-binding mode of Sudan I-IV with ct-DNA. The molecular modeling computational method also proved binding mode, which is consistent with the spectral experiments. In addition, the aromatic rings of Sudan I-IV play important roles in binding with DNA. Compared to Sudan I and II, the increase of molecular conjugation system enhances the binding abilities of Sudan III and Sudan IV with DNA. Vdm + Hbond + desolv energies of them are the main contribution of their combined energies.
研究领域:
生物化学
·
食品安全
·
分子生物学
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DOI
PubMed
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2018
·Vol. 16
·期 31
·5667-5676
·
IF 3.423
Li Huang,Ying-Juan Cao,Xiang-Ying Sun,Bin Liu,Jiang-Shan Shen
Extending the research on 3,3′,5,5′-tetramethylbenzidine (TMB) and its derivatives in analytical chemistry is important, considering that TMB is widely used as an enzyme catalytic substrate. In this work, two TMB derivatives, TMBS and TMBB, were synthesized via a facile and one-step condensation reaction between the –NH2 group of TMB and the –CHO group of salicylaldehyde or benzaldehyde. Because at low pH the two Schiff base compounds can release TMB which can emit strong fluorescence, the probes could show dual-modal signal responses, fluorescence and UV-vis absorption, towards the pH. Practical applications of pH sensing in Chinese rice vinegar and lemon juice samples were successfully demonstrated. On the basis of these findings, a catalytic chromogenic reaction was developed to monitor the pH with the naked eye, too. Furthermore, considering the chemical equilibrium reaction between CO2 and H2O and that glucose oxidase (GOD) can catalyse the dehydrogenation and oxidation reaction of β-D-glucose to produce gluconic acid, both of which can result in lowering the pH values of the two Schiff base systems, highly sensitive and selective dual-modal sensing systems for detecting CO2 and β-D-glucose have also been successfully established. Therefore, the two synthesized TMB derivatives can demonstrate their robust application potential.
研究领域:
分析化学
·
生物传感
·
酶催化反应
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DOI
PubMed
高影响因子
SOLAR ENERGY
·
2018
·
IF 4.374
Huajun Chen,Wenjie Tian,Wuxiu Ding
Metallic sliver-doped mesoporous Al 2 O 3 fibers (meso-Ag/Al 2 O 3 ) that can harvest visible light to speed up solar water purification, were synthesized by one-pot hydrothermal method. Insightful analyses of XRD, XRF and XPS of meso-Ag/ Al 2 O 3 verified that metallic silver occupied interstitial positions of Al 2 O 3 lattice forming interstitial solid solution. N 2 adsorption/desorption illustrated that meso-Ag/Al 2 O 3 exhibited significantly increases in the specific surface area, pore volume and average pore diameter after doping with silver. The UV–Vis diffuse reflectance spectra and disinfection performance indicated that meso-Ag/Al 2 O 3 can harvest visible light to promote the conversion of dioxygen to ROS for water disinfection compared with the widely used TiO 2 . With our approach, we achieved water disinfection of >99.999% inactivation of bacteria in 120 min with a small amount of material (8 mg/L) under simulated visible light.
研究领域:
环境科学
·
材料科学
·
水处理
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DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2021
·Vol. 23
·期 3
·1-12
·
IF 2.253
Mao Xisong,Xia Xuewen,Ning Deyang,Li Junqi,Chen Chaoyi,Lan Yuan-Pei
Molten salts synthesis (MSS) is a simple and potential technique for ceria nanoparticles (NPs) production, but the relevant effects of salt medium and cerium precursor on the synthesized ceria NPs need further attention. In the present work, we investigated the influences of frequently employed KCl–LiCl and KOH–NaOH molten flux and typical inorganic cerium precursors on the characterizations and photocatalytic property of ceria NPs. Results show that the CeO 2 NPs obtained in molten KOH–NaOH flux have smaller particle/crystal sizes but more serious agglomeration than that from KCl–LiCl flux. UV–Vis DRS spectra reveal that the ceria synthesized in molten hydroxides from the cerium nitrate precursor has the narrowest band gap of 2.87 eV in studied ceria samples. The ceria NPs obtained from KCl–LiCl flux have wider band gaps of 3.15–3.29 eV and faster recombination rates of photo-generated e − and h + . It was found that the ceria NPs obtained in molten KCl–LiCl salt show better photocatalytic activities for methylene blue (MB) degradation and may be due to the uniform size distribution and well-dispersed particles.
研究领域:
材料科学
·
化学
·
纳米技术
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2014
·
IF 2.93
Junxian Wang,Jie Huang,Haolong Xie,Ailan Qu
A photocatalyst composed of graphite-like carbon nitride (g-C 3 N 4 ) and TiO 2 was fabricated by a simple method to calcine the mixture of melamine and TiO 2 precursor. The photocatalyst has enhanced photoactivity for hydrogen evolution from water. Characterization by XRD , FTIR, SEM and elemental analysis showed that the crystal structure and morphologies of composites were affected by the amount of melamine in the composite. The UV–Vis characterization displayed that the optical absorption range of g-C 3 N 4 /TiO 2 hybrid was broadened with a synergistic effect . The photoactivity for H 2 evolution was shown that the best result obtained from the composite with 67 wt% melamine has about 5 times improvement compared with bare TiO 2 or pure g-C 3 N 4 . The enhanced photoactivity might be related with the favorable structure resulted from heat-treatment temperature, and the content of g-C 3 N 4 participating in wide optical absorption, separation and transportation of electronic-holes, as well as morphology of composite.
研究领域:
材料科学
·
光催化
·
氢能
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）