Science China-Chemistry
·
2017
·Vol. 60
·期 9
·1243-1249
·
IF 4.132
Zhang Honghua,Liu Ruixia,Zhang Ruirui,Huo Feng,Yang Zhiqiang,He Bin,Zhang Suojiang,Wang Yanji
Ionic liquid coupled with strong acid systems presents considerable promise in some catalytic fields. In the present work, the multiple complex systems composed by 98 wt% concentrated sulfuric acid and [Bmim][SbF 6 ] were investigated in the terms of stability, acidity and interaction properties. It was found that acidolysis of [Bmim][SbF 6 ] occurred in the 98 wt% concentrated sulfuric acid accompanied by HF releasing and SbF
− 6
degrading to [SbF 6− y
(HSO 4 )
y
] − . The species after acidolysis in the multiple complex systems were checked and confirmed by electrospray ionization mass spectrometry (ESI-MS), Fourier transform infrared spectroscopy (FT-IR), 1 H NMR and 19 F NMR. Acidity increased slightly with less than 1 wt% [Bmim][SbF 6 ] addition, while decreased with more proportion, which was determined based on the Hammett acidity functions H 0 , using 13 C NMR. The strong hydrogen bond S–O–H···F of interaction among the multiple complex systems was confirmed by molecular dynamic simulation.
研究领域:
化学
·
催化领域
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Xumin Xu,Hongyu Wei,Mingguang Liu,Laishui zhou,Guozhu Shen,Qin Li,Ghulam Hussain,Fan Yang,Reham Fathi,Haiji Chen,Kostya (Ken) Ostrikov
In recent years, steel corrosion, an issue affecting a trillion-dollar industry, is being addressed with nanotechnology technologies. Small clusters and nanoparticles , as well as numerous molecules, are viable solutions, with carbon quantum dots (CQDs) being among the best and most promising. However, the complexity and duration of the CQDs purification process, as well as a few other issues, limit their practical applications as corrosion inhibitors . Therefore, in this study, a new type of nitrogen-doped CQDs (N-CQDs) with an average size of 2.5 ± 0.8 nm were synthesized via hydrothermal reaction of amino-guanidine and citric acid using a robust purification process. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques were used to evaluate the new inhibitor's corrosion mitigation effect on Q235 steel in 0.5 M H 2 SO 4 solution. X-ray photoelectronic spectroscopy (XPS) and FTIR analyses were employed for the chemical composition investigation of as-prepared N-CQDs and surface characterization of Q235 steel samples. The analysis of the impedance module and the current density of Q235 steel in the corrosive solution validates the effective protective performance of the inhibitor. The results showed that the maximum inhibition efficiency of 95.3% was achieved at the concentration of 200 mg/L. Moreover, it was found that the formation of the protective layer on the steel samples results from the Physico-chemical adsorption of the inhibitor on the steel surface and follows the Langmuir adsorption isotherm that was also confirmed via XPS. The quantum chemical calculations show that CQD nitrogen doping has an effect on corrosion inhibition performance. Overall, the corrosion inhibition efficiency of the carbon dots inhibitor is higher at the same concentration than that of most other similar inhibitor types.
研究领域:
材料科学
·
腐蚀与防护
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2020
·
IF 4.473
Yang Dong,Ming Jia,Yuanyuan Wang,Jianzhong Xu,Yongchang Liu,Lifang Jiao,Ning Zhang
Rechargeable aqueous zinc/vanadium pentoxide (Zn/V2O5) battery chemistry has recently attracted a great attention due to its high safety, material abundance, cost effectiveness, and desirable energy density. However, the reaction mechanism of V2O5 in an aqueous electrolyte remains a topic of discussion, and the limited life span resulting from the active materials dissolution hinders the further development of the Zn/V2O5 battery. Here, we report a long-life aqueous Zn/V2O5 battery using a simply ball-milled V2O5 cathode, a concentrated aqueous ZnSO4 electrolyte, and a metallic Zn anode. Electrochemical, structural, and spectroscopic analyses reveal that the V2O5 electrode experiences a highly reversible proton (H+) and Zn2+ co-intercalation mechanism in aqueous media, which differs from the conventional cognition that Zn2+ ion as the only charge carrier inserts into the V2O5 host. The electrolyte-involved (dis)appearance of zinc sulfate hydroxide on the electrodes’ surface caused by H+ (de)intercalation has also been clarified. In addition, the optimized 3 M ZnSO4 electrolyte can not only suppress the dissolution of the V2O5 cathode but also enhance the stability of the Zn anode, thereby enabling the stable operation of the Zn/V2O5 battery with a reversible capacity of 357 mAh g–1 after 2000 cycles without obvious decay at 2.0 A g–1. This work opens up frontiers in the mechanism insight and electrolyte formulation for aqueous Zn batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2014
·Vol. 119
·期 1
·205-212
·
IF 2.206
Yang Ting,Chen Liping,Chen Wanghua,Zhou Yishan,Gao Haisu,Zhong Tingting
2-Ethylhexyl nitrate (EHN) is an important material, which is produced by concentrated HNO 3 –H 2 SO 4 nitration process. But EHN is not a stable material, especially mixed with acids. To analyze the stability of EHN with concentrated acid under serious condition, four samples (pure EHN, concentrated sulfuric acid with EHN, concentrated nitric acid with EHN, and mixed acid with EHN) and three acids (sulfuric acid, nitric acid, and mixed acid) were measured by differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC) in this paper. The results indicated that concentrated sulfuric acid, concentrated nitric acid, and mixed acid all could decrease the onset decomposition temperature of EHN, especially concentrated sulfuric acid. DSC results also showed that the heat of EHN decomposition with nitric acid is larger than other samples. Based on ARC data, the kinetic parameters and T
D24 (temperature at which TMR
ad is 24 h) were calculated. The activation energy and T
D24 of the EHN with acids, especially with concentrate sulfuric acid, were much lower than the pure EHN. It can be concluded that acids could decrease the stability of EHN and that is an important reason for frequent accidents.
研究领域:
物理化学
·
安全工程
·
材料化学
·
热分析
·
危险品管理
✓ 已验证
DOI
高影响因子
Journal of the Mechanical Behavior of Biomedical Materials
·
2024
·
IF 3.3
Wen Qin,Tong Xing,Jing Ma,Bin Tang,Weiyi Chen
Due to the unique lamellar structures , physicochemical and biological properties, electronegative two-dimensional (2D) materials have been explored for surface modification of carbon fibers reinforced polyetheretherketone (CFR-PEEK) composite. Deposition of electronegative 2D materials based on a porous surface created by concentrated H 2 SO 4 has been studied to promote osteogenesis of CFR-PEEK. Generally, a porous layer will be pre-built on CFR-PEEK through severe corrosion of concentrated sulfuric acid to help the loading of 2D materials . However, the severe corrosion will greatly reduce surface mechanical strength , especially wear resistance and hardness, which increases the risk of collapse or even peeling of the bioactive coating by external force. Herein, instead of the severe corrosion, a mild corrosion by concentrated HNO 3 was applied to modify the surface of CFR-PEEK to pre-create a dense transition layer for the further surface decoration of electronegative 2D materials (graphene oxide (GO) and black phosphorus (BP), representatively). The results indicated that hardness and wear resistance of the dense transition layer were markedly higher than those of the porous layer. Although GO and BP can be both loaded on these two transition layers, –SO 3 H on the porous transition layer showed moderate cytotoxicity, while –NO 2 on the dense transition layer showed good cytocompatibility. The dense transition layer displayed higher mineralized deposition in vitro and new bone formation rate in vivo than the porous transition layer, moreover, GO and BP coatings improved osteogenesis. This work offers inspirations for the construction of electronegative 2D material coating on CFR-PEEK based on chemical transition layers.
研究领域:
材料科学
·
生物材料
·
生物医学工程
·
骨科
✓ 已验证
DOI
PubMed
高影响因子
Journal of Food Measurement and Characterization
·
2019
·Vol. 13
·期 4
·2713-2721
·
IF 1.415
Yan Jun,Huang Xiao-Ping,Wu Ye-Yu,Du Fang-Kai,Tan Xue-Cai,Wang Qi,Zhu Wei-Wei
Abstract Near-infrared (NIR) diffuse reflectance spectroscopy has become an attractive technique for quality assurance of fruits, drugs, vegetables, and foods. In this work, the information on chemical composition of Siraitia grosvenorii was acquired by NIR, and then a calibration model for the prediction of total sugar content (TSC) was developed using chemometric techniques. One hundred and fifty samples were used as calibration set to develop model, while 40 unknown samples were used for prediction, using phenol-concentrated sulphuric acid assay as reference value. Several spectra preprocessing methods and wavelength selection techniques combined with partial least squares regression were compared, and then standard normal variate coupled with Savitzky–Golay derivative was selected for spectra processing and competitive adaptive reweighted sampling method was applied to extract the informative wavelengths related to the prediction of TSC. The performance of the obtained model has been evaluated by external validation, the square of correlation coefficient (R 2 ) are 0.9097 for a separate blind set consists of 40 unknown samples. Additionally, the result of paired t test ( p = 0.3608) illustrated that there is no significant differences between NIR and wet chemistry analysis. These results demonstrated that NIR spectroscopy has the potential to be a time saving and cost-effective method for the determination of the TSC in S. grosvenorii . Graphic abstract
研究领域:
食品科学
·
分析化学
·
质量保证
✓ 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）