Charge transfer processes in the course of metal-ion electrochemical intercalation

Charge transfer in the course of the electrochemical ion intercalation is typically understood as the transfer of an alkali metal ion across the intercalating material/electrolyte interface. The activation energy of this step determines the rate capability of intercalation-based energy storage devices, which calls for the investigation of the origin of the charge transfer limitations in various intercalation systems. The major focus of the experimental studies in this area is on the experimental determination of the charge transfer rates under different experimental conditions, while molecular modeling approaches allow to unveil the mechanistic aspects of the intercalation processes.     

Evaluation of a PEG/hydroxypropyl starch aqueous two‐phase system for the separation of monoclonal antibodies from cell culture supernatant

In this study, an aqueous two‐phase system (ATPS) with PEG and hydroxypropyl starch (HPS) was used to separate monoclonal antibody (mAb) from Chinese hamster ovary cell culture supernatant. The phase diagram of the PEG/HPS ATPS was determined, and the effects of NaCl addition were investigated. The results showed that NaCl addition could lead to a shift of the binodal curve and that phase separation would occur at higher PEG and HPS concentrations. The effects of NaCl addition, pH, and the load of cell supernatant on the partitioning of mAb in a PEG/HPS ATPS were investigated. It was found that with 6% cell supernatant and 15% NaCl addition at pH 6.0, the yield of mAb in the upper phase was 96.7% with a purity of 96.0%. The back‐extraction of mAb with a PEG/phosphate ATPS were also studied, and the results showed that after the two‐step extraction with ATPSs the purity of mAb could reach 97.6 ± 0.5% with a yield of 86.8 ± 1.0%, which was comparable to the purification with Protein A chromatography. These results indicate that the two‐step extraction with PEG/HPS and PEG/phosphate ATPSs might be a promising alternative for the separation of mAb from cell culture supernatant.     

铀酰离子在羟基化α-石英(101)表面的吸附

采用周期性密度泛函理论研究羟基化α-石英(101)面的铀酰离子吸附行为.通过对铀酰离子的水合作用考虑水溶剂对结构的短程溶剂化效应,并通过类导体屏蔽模型(COSMO)考虑水溶剂对结构的远程溶剂化效应.吸附能计算结果和电子结构数据均表明水合铀酰离子吸附构型比氢氧化铀酰吸附构型稳定,并且在液相中两种类型的稳定吸附位均为dia-Os1Os2位.两种形式在电子结构上有很大的差异,主要是由于铀与表面作用后成键强弱程度不同,使5f轨道宽化和略微红移存在差异.在铀酰离子吸附的基础上利用卤素离子改变铀酰离子配位环境可调整体系的带隙.     

Gas purge-microsyringe extraction: A rapid and exhaustive direct microextraction technique of polycyclic aromatic hydrocarbons from plants

Gas purge-microsyringe extraction (GP-MSE) is a rapid and exhaustive microextraction technique for volatile and semivolatile compounds. In this study, a theoretical system of GP-MSE was established by directly extracting and analyzing 16 kinds of polycyclic aromatic hydrocarbons (PAHs) from plant samples. On the basis of theoretical consideration, a full factorial experimental design was first used to evaluate the main effects and interactions of the experimental parameters affecting the extraction efficiency. Further experiments were carried out to determine the extraction kinetics and desorption temperature-dependent. The results indicated that three factors, namely desorption temperature (temperature of sample phase) T_d, extraction time t, and gas flow rate u, had a significantly positive effect on the extraction efficiency of GP-MSE for PAHs. Extraction processes of PAHs in plant samples followed by first-order kinetics (relative coefficient R² of simulation curves were 0.731–1.000, with an average of 0.958 and 4.06% relative standard deviation), and obviously depended on the desorption temperature. Furthermore, the effect of the matrix was determined from the difference in E_app,d. Finally, satisfactory recoveries of 16 PAHs were obtained using optimal parameters. The study demonstrated that GP-MSE could provide a rapid and exhaustive means of direct extraction of PAHs from plant samples. The extraction kinetics were similar that of the inverse process of the desorption kinetics of the sample phase.     

Green and Rapid Strategy for Synthesis of Novel and Known Pyrroles by the Use of Molybdate Sulfuric Acid

Molybdate sulfuric acid as a highly efficient catalyst has been employed for the modified Paal–Knorr synthesis of some novel and known pyrroles under solvent‐free conditions. Catalyst loads as low as 1 mol% could be used leading to high yields of pure pyrrole derivatives at an oil bath temperature of 60 °C. This method has advantages such as the use of very low amounts of a recyclable catalyst, avoidance of organic solvents, and high product yields.     

A Total Solution to Baseline Separation of 20 Brominated Flame Retardant Additives in Electronic Products with Automated Soxhlet Hot Extraction and Gas Chromatography‐Mass Spectrometry

An efficient and reliable separation technique based on automated Soxhlet hot extraction (AHSE) was developed and validated. It can be applied to rapid separations of 20 persistent organic pollutants, including two types of brominated flame retardants (BFRs), polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) contained in nonmetallic component parts of electronic products. The qualitative chromatographic analyses were carried out by using a gas chromatography coupled with a mass spectrometry detector (GC‐MS). The 20 persistent organic pollutants were simultaneously and completely separated by a 15 meter HP‐5MS short capillary column in 25 minutes. Through the tests of extraction performance, effects of solvent and extraction time on selected BFRs were investigated; toluene and 120 min extraction time were chose as the optimum conditions. Besides, this article examines the influence of temperature on the chromatographic analysis, the optimum temperature parameters were 280 °C and 320 °C for injector and column, respectively. The ASHE‐GCMS method was validated for the analysis of the certified reference material of CRM8110‐a and IRMM310. The limits of detection (LOD) for polymer sample was 0.55‐4.50 μg mL^?1; linearity range from 0.11 to 16 μg mL^?1. The proposed methodology can fully meet the requirement of relational directives.     

Synthesis of Pyrrolo [3,4-c] [1] benzazepine-4, 10 (2H, 5H)-dione,a Model System Useful for the Design of 11-Oxosibiromycinone Analogues

The synthesis of pyrrolo[3,4-c] [1] benzazepine-4,10(2H, 5H)-dione, a compound related to 11-oxosibiromycinone, is described. 2-Methyl-, 5-methyl- and 2,5-dimethylpyrrolo[3,4-c] [1] benzazepine-4, 10 (2H, 5H) - dione have been also prepared. The title compound has been synthesized either by ring enlargement of 2H-benz [f] isoindole-4,9-dione or by TosMIC addition to 1H-1-benzazepin-2,5-dione.     

Studies of Solvent Effects on Structure and Low Frequency Vibrational Spectra of 2,4-Dinitrotoluene

Solvent effects on 2,4-dinitrotoluene(2,4-DNT) molecule in different solvents(toluene,ethanol,and water) were studied via DFT PCM method at B3LYP/6-311+G(d,p) level. The influences of these solvents on the molecular structure,vibrational spectra,charge distribution,and dipole moment were studied as well. The results show that PCM computations are successful in describing the vibrational spectra of 2,4-DNT molecules in these solutions and the solvent effects on the low frequency vibrational spectra are weak.     

异丙基膦酸单异辛酯负载树脂用于萃取色层以分离稀土元素

本文报道异丙基膦酸单异辛酯负载树脂分离稀土(Ⅲ)的性能。实验结果表明采用不同浓度的稀盐酸淋洗可依次分离15种稀土(Ⅲ)。除钇(Ⅲ)/铒(Ⅲ)对(R.1.0)外,其余各相邻稀土(Ⅲ)均达到基线分离(R_a≥1.5)。所用酸度不超过2.0mol/L,低于常用的磷酸双(2-乙己基)酯(HDEHP)和2-乙已基膦酸单2-乙己基酯(HEHEHP)所需酸度。     

同时测定重油中铁和锌的正三辛胺萃取-双波长K系数分光光度法

用正三辛胺萃取分离干扰离子，以Ｆｅ２＋（Ｚｎ２＋）－５＿Ｂｒ＿ＰＡＤＡＰ（２－（５－溴－２－吡啶偶氮）－５－二乙基氨基苯酚）－ＴｒｉｔｏｎＸ＿１００为显色体系，建立了双波长Ｋ系数法同时测定重油中微量铁、锌的新方法。考查了测定条件及萃取分离条件。线性范围：铁０～４８０μｇ／Ｌ、锌０～４００μｇ／Ｌ，合成样回收率（１００±２）％，重油测定结果的相对标准偏差小于５％。方法简便、准确。