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Organolead trihalide perovskite materials for efficient light emitting diodes
Ming Peng, Wen Wen, Si Chen, Buxin Chen, Kai Yan, Hsienwei Hu, Bin Dong, Xue Gao, Xiao Yu, Xiaoming Jiang, Dechun Zou

Organolead trihalide perovskite materials have been attracting increasing attention due to their promising role in solid solar cells. Several advantages make them potential candidates for optoelectronics:(1) solution-or/and vapor-processed preparation at low temperature;(2) tunable optical bandgap, wide absorption spectrum but narrow photoluminescence peaks;(3) long carrier life time, large diffusion length and high charge mobility;(4) various nanostructures via tuning capping agents and solvents. In this review, we summarize recent attempts toward efficient LEDs based on organolead trihalide perovskite materials. The strategies of materials science, device design, interface engineering are highlighted. Recent development and future perspectives are summarized for practical perovskite light technologies.

[Abstract] ( 288 ) [PDF 842 KB] ( 159 )  [Supporting InformationDOI: 10.1007/s11426-015-5522-7
Published Online: 2016-04-13
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Electrochemical reduction of CO2 to CO using graphene oxide/carbon nanotube electrode in ionic liquid/acetonitrile system
Qinggong Zhu, Jun Ma, Xinchen Kang, Xiaofu Sun, Jiayin Hu, Guanying Yang, Buxing Han

Electrochemical reduction of CO2 to CO is an interesting topic. In this work, we prepared metal-free electrodes by depositing graphene oxide (GO), multi walled carbon nanotube (MWCNT), and GO/MWCNT composites on carbon paper (CP) using electrophoretic deposition (EPD) method. The electrodes were characterized by different methods, such as X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical reduction of CO2 to CO was conducted on the electrodes in 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4)/acetonitrile (MeCN) electrolyte, and the composition of the electrolyte influenced the reaction significantly. It was demonstrated that GO/MWCNT-CP electrode was very effective for the reaction in IL (90 wt%)/MeCN binary mixture, the Faradaic efficiency of CO and current density were even higher than those on Au and Ag electrodes in the same electrolyte.

[Abstract] ( 134 ) [PDF 839 KB] ( 127 )  [Supporting InformationDOI: 10.1007/s11426-016-5584-1
Published Online: 2016-04-07
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Extraction mechanism of rare earths from chloride acidic solution with ammonium-bifunctionalized ionic liquid extractants
Hualing Yang, Ji Chen, Wei Wang, Hongmin Cui, Wengang Liu, Yu Liu

A series of ammonium-bifunctionalized ionic liquid extractants (ammonium-Bif-ILEs) combined with a number of anions, including carboxylic acids and 1,3-diketonates, have been prepared and studied in this report. Their extraction behavior and properties toward rare earth ions (REs(III)) are systematically investigated in chloride media as a function of important parameters such as aqueous phase pH, salting-out agent concentrations, and extraction temperature. The separation performance of ammonium-Bif-ILEs toward REs(III) are systematically discussed. The results demonstrate that ammonium-Bif-ILEs have a synergistic effect between the cation and anions in separation of REs(III). The influences of different anions on separation factor (β) values are further studied. By comparison, ammonium-Bif-ILEs containing 1,3-diketonates have more potential applications in La(III)/RE(III) separation than those containing carboxylic acids.

[Abstract] ( 95 ) [PDF 546 KB] ( 119 )  [Supporting InformationDOI: 10.1007/s11426-016-5585-0
Published Online: 2016-04-07
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Microscopic study of binary mixtures between pyrrolidinium bis(triflorosulfonyl)imide and dimethyl sulfoxide/acetonitrile
Hamad Ashraf, Yu Zhou, Jing Xu, Khalil Ahmad, Zhi-Wu Yu

Molecular interactions of a representative pyrrolidinium-based ionic liquid 1-butyl-1-methyl-pyrrolidinium bis(triflorosulfonyl)imide ([BMPyrr][TFSI]) with dimethyl sulfoxide (DMSO) and acetonitrile (AN) have been analyzed in this work. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and density functional theory (DFT) calculations are used in the investigation, while excess infrared spectra and two-dimensional correlation spectroscopy are used to explore the data in detail. It has been found that the molecular solvents can interact with TFSI- (mainly with S=O and weakly with S-N-S group). AN interacts feebly with BMPyrr+ as compared with the strong interaction of DMSO. The strength of the interactions depends on the electron donating ability of the solvent. Upon mixing, hydrogen bonds regarding C-Hs in cation and S-N-S in anion are weakened, while that regarding S=O in anion is strengthened. Among the C-Hs which are connected directly with the N of the cation, C1-H is the main interaction site for both DMSO and AN. This means that C1-H is the most acidic hydrogen in pyrrolidinium cation.

[Abstract] ( 115 ) [PDF 2426 KB] ( 82 )  [Supporting InformationDOI: 10.1007/s11426-016-5583-2
Published Online: 2016-04-07
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Which is the determinant for cellulose degradation in cooperative ionic liquid pairs: dissolution or catalysis
Jinxing Long, Yangyu Zhang, Lefu Wang, Xuehui Li

Catalytic conversion of sustainable cellulose to the value-added chemicals and high quality biofuel has been recognized as a perfect approach for the alleviation of the dependence on the non-renewable fossil resources. Previously, we successfully designed and explored novel and efficient cooperative ionic liquid pairs for this renewable material, which has advantages of high reactor efficiency than current technologies because of the dissolution and in situ catalytic decomposition mechanism. Here, the determinant of this process is further studied by the intensive investigation on the relationship between the cellulose conversion and the properties of ionic liquid catalyst and solvent. Scanning electron microscope (SEM), thermogravimetric analysis (TG) and elemental analysis were used for the comparative characterization of raw cellulose and the residues. The results demonstrate that this consecutive dissolution and in situ catalysis process is much more dependent on the dissolution capability of ionic liquid solvent, while comparatively, the effect of in situ acid catalysis is relatively insignificant.

[Abstract] ( 82 ) [PDF 1214 KB] ( 118 )  [Supporting InformationDOI: 10.1007/s11426-016-5586-z
Published Online: 2016-04-07
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Novel ionic liquid based electrolyte for double layer capacitors with enhanced high potential stability
Lan Zhang, Kun Dong, Shimou Chen, Suojiang Zhang

Developing electrolyte with high electrochemical stability is the most effective way to improve the energy density of double layer capacitors (DLCs), and ionic liquid is a promising choice. Herein, a novel ionic liquid based high potential electrolyte with a stabilizer, succinonitrile, was proposed to improve the high potential stability of the DLC. The electrolyte with 7.5 wt% succinonitrile added has a high ionic conductivity of 41.1 mS cm-1 under ambient temperature, and the DLC adopting this electrolyte could be charged to 3.0 V with stable cycle ability even under a discharge current density of 6 A g-1. Moreover, the energy density could be increased by 23.4% when the DLC was charged to 3.0 V compared to that charged to 2.7 V.

[Abstract] ( 107 ) [PDF 720 KB] ( 99 )  [Supporting InformationDOI: 10.1007/s11426-016-5588-x
Published Online: 2016-04-07
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N-methyl-2-pyrrolidonium-based Brönsted-Lewis acidic ionic liquids as catalysts for the hydrolysis of cellulose
Zheng Zhao, Na Li, Abdul Waheed Bhutto, Ahmed A. Abdeltawab, Salem S. Al-Deyab, Guangqing Liu, Xiaochun Chen, Guangren Yu

We experimentally studied the catalytic performances of a series of Brönsted-Lewis acidic N-methyl-2-pyrrolidonium metal chlorides ([Hnmp]Cl/MClx, where M=Fe, Zn, Al, or Cu) for the hydrolysis of microcrystalline cellulose (MCC) and cotton to produce reducing sugar. A variety of factors, such as temperature, time, ionic liquid (IL) species, IL dosage, and the concentration of the metal chloride were investigated. [Hnmp]Cl/FeCl3 presented the best hydrolysis performance, affording a 98.8% yield of total reducing sugar from MCC (1 h, 100℃, 0.1 g MCC, 0.2 g acidic IL, 2.0 g [Bmim]Cl as solvent), which is better than or comparable to results previously obtained with other -SO3H functionalized acidic ILs. The hydrolysis performances of [Hnmp]Cl/MClx were rationalized using density functional theory calculations, which indicated that interactions between the metal chlorides and the cellulose, including charge-transfer interactions are important in the hydrolysis of cellulose and degradation of glucose. This work shows that Brönsted-Lewis acidic ILs are potential catalysts for the hydrolysis of cellulose to produce sugar.

[Abstract] ( 104 ) [PDF 800 KB] ( 235 )  [Supporting InformationDOI: 10.1007/s11426-016-5592-1
Published Online: 2016-04-07
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Special Issue on Ionic Liquids: Energy, Materials & Environment
Suojiang Zhang, Buxing Han, Jianji Wang
[Abstract] ( 126 ) [PDF 312 KB] ( 54 )  [Supporting InformationDOI: 10.1007/s11426-016-5598-8
Published Online: 2016-04-06
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One-step preparation of branched PEG functionalized AIE-active luminescent polymeric nanoprobes
Jun Chu, Qiulan Lv, Chunliang Guo, Dazhuang Xu, Ke Wang, Meiying Liu, Hongye Huang, Xiaoyong Zhang, Yen Wei

The synthesis of amphiphilic aggregation-induced emission (AIE) dyes based organic nanoparticles has recently attracted increasing attention in the biomedical fields. These AIE dyes based nanoparticles could effectively overcome the aggregation caused quenching effect of conventional organic dyes, making them promising candidates for fabrication of ultrabright organic luminescent nanomaterials. In this work, AIE-active luminescent polymeric nanoparticles (4-NH2-PEG-TPE-E LPNs) were facilely fabricated through Michael addition reaction between tetraphenylethene acrylate (TPE-E) and 4-arm-poly(ethylene glycol)-amine (4-NH2-PEG) in rather mild ambient. The 4-NH2-PEG can not only endow these AIE-active LPNs good water dispersibility, but also provide functional groups for further conjugation reaction. The size, morphology and luminescent properties of 4-NH2-PEG-TPE-E LPNs were characterized by a series of techniques in detail. Results suggested that these AIE-active LPNs showed spherical morphology with diameter about 100-200 nm. The obtained 4-NH2-PEG-TPE-E LPNs display high water dispersibility and strong fluorescence intensity because of their self assembly and AIE properties of TPE-E. Biological evaluation results demonstrated that 4-NH2-PEG-TPE-E LPNs showed negative toxicity toward cancer cells and good fluorescent imaging performance. All of these features make 4-NH2-PEG-TPE-E LPNs promising candidates for biological imaging and therapeutic applications.

[Abstract] ( 209 ) [PDF 1027 KB] ( 32 )  [Supporting InformationDOI: 10.1007/s11426-016-5578-z
Published Online: 2016-03-30
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Dynamic separation of Xe and Kr by metal-organic framework and covalent-organic materials: a comparison with activated charcoal
Qian Wang, Shunshun Xiong, Zhonghua Xiang, Shuming Peng, Xiaolin Wang, Dapeng Cao

We systematically investigate dynamic separation of Xe and Kr at room temperature using four representative porous materials (Cu-BTC, ZIF-8, COP-4 and activated carbon (AC)). Results indicate that among the four materials, Cu-BTC not only shows the highest retention volume per gram (Vg=788 mL g-1, which is 1.8 times of activated carbon (436 mL g-1)) under flowing condition, but also can separate 350 ppm Xe from 35 ppm Kr mixture in air with a high Xe/Kr selectivity of 8.6 at room temperature and 200 kPa, due to its suitable pore morphology, open metal sites, small side pockets in the framework. Moreover, the Cu-BTC also performs well on individual separation of Xe, Kr, CO2 from five-component gas mixture (Xe:Kr:CO2:Ar:N2=1:1:1:1:0.5, V/V) and has the longest retention time for Xe (20 min) in gas chromatographic separation, suggesting that it is a good candidate for potential applications as polymeric sieves.

[Abstract] ( 137 ) [PDF 1003 KB] ( 259 )  [Supporting InformationDOI: 10.1007/s11426-016-5582-3
Published Online: 2016-03-30
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A pH-responsive activatable aptamer probe for targeted cancer imaging based on i-motif-driven conformation alteration
Lv'an Yan, Hui Shi, Dinggeng He, Xiaoxiao He, Kemin Wang, Fengzhou Xu

We present here a pH-responsive activatable aptamer probe for targeted cancer imaging based on i-motif-driven conformation alteration. This pH-responsive activatable aptamer probe is composed of two single-stranded DNA. One was used for target recognition, containing a central, target specific aptamer sequence at the 3'-end and an extension sequence at the 5'-end with 5-carboxytetramethylrhodamine (TAMRA) label (denoted as strand A). The other (strand I), being competent to work on the formation of i-motif structure, contained four stretches of the cytosine (C) rich domain and was labeled with a Black Hole Quencher 2 (BHQ2) at the 3'-end. At neutral or slightly alkaline pH, strand I was hybridized to the extension sequence of strand A to form a double-stranded DNA probe, termed i-motif-based activatable aptamer probe (I-AAP). Because of proximity- induced energy transfer, the I-AAP was in a "signal off" state. The slightly acidic pH enforced the strand I to form an intramolecular i-motif and then initiated the dehybridization of I-AAP, leading to fluorescence readout in the target recognition. As a demonstration, AS1411 aptamer was used for MCF-7 cells imaging. It was displayed that the I-AAP could be carried out for target cancer cells imaging after being activated in slightly acidic environment. The applicability of I-AAP for tumor tissues imaging has been also investigated by using the isolated MCF-7 tumor tissues. These results implied the I-AAP strategy is promising as a novel approach for cancer imaging.

[Abstract] ( 81 ) [PDF 827 KB] ( 109 )  [Supporting InformationDOI: 10.1007/s11426-016-5575-2
Published Online: 2016-03-29
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Tunable LCST-type phase behavior of [FeCl4]--based ionic liquids in water
Yuanchao Pei, Yuan Cao, Yanjie Huang, Xinxin Song, Huiyong Wang, Yuling Zhao, Jianji Wang

In this work, 16 kinds of [FeCl4]--based magnetic ionic liquids (ILs) with different cation structures have been designed and synthesized, and their structures are characterized by IR and Raman spectroscopy. Then the lower critical solution temperature (LCST)-type phase behavior of these magnetic ILs in water is investigated as a function of concentration. It is shown that cation structure, alkyl chain length and molar ratio of FeCl3/chloride IL have a significant influence on the LCST of the mixtures. The phase separation temperature can be tuned efficiently by these factors. Meanwhile, the LCST-type phase separation process is also investigated by dynamic light scattering. The results support the mechanism that the hydrogen bonds of the [FeCl4]- anion with water have been gradually disrupted to form ILs aggregates with increasing temperature. In addition, the stability of the ILs in water is also examined in some details. These LCST-type phase separation systems may have potential applications in extraction and separation techniques at room temperature.

[Abstract] ( 161 ) [PDF 871 KB] ( 115 )  [Supporting InformationDOI: 10.1007/s11426-016-5577-0
Published Online: 2016-03-28
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Molecular simulation study of dynamical properties of room temperature ionic liquids with carbon pieces
Guang Feng, Wei Zhao, Peter T. Cummings, Song Li

Room temperature ionic liquids (RTILs) with dispersed carbon pieces exhibit distinctive physiochemical properties. To explore the molecular mechanism, RTILs/carbon pieces mixture was investigated by molecular dynamics (MD) simulation in this work. Rigid and flexible carbon pieces in the form of graphene with different thicknesses and carbon nanotubes in different sizes were dispersed in a representative RTIL 1-butyl-3-methyl-imidazolium dicyanamide ([Bmim][DCA]). This study demonstrated that the diffusion coefficients of RTILs in the presence of flexible carbons are similar to those of bulk RTILs at varying temperatures, which is in contrast to the decreased diffusion of RTILs in the presence of rigid carbons. In addition, interfacial ion number density at rigid carbon surfaces was higher than that at flexible ones, which is correlated with the accessible external surface area of carbon pieces. The life time of cation-anion pair in the presence of carbon pieces also exhibited a dependence on carbon flexibility. RTILs with dispersed rigid carbon pieces showed longer ion pair life time than those with flexible ones, in consistence with the observation in diffusion coefficients. This work highlights the necessity of including the carbon flexibility when performing MD simulation of RTILs in the presence of dispersed carbon pieces in order to obtain the reliable dynamical and interfacial structural properties.

[Abstract] ( 149 ) [PDF 1602 KB] ( 115 )  [Supporting InformationDOI: 10.1007/s11426-016-5580-5
Published Online: 2016-03-28
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Recent progress in studies on polarity of ionic liquids
Xinyu Wang, Kexian Chen, Jia Yao, Haoran Li

Although many ionic liquids have been reported, their polarity is not completely understood. Different empirical polarity scales for molecular solvents always lead to different polarity orders when they are applied on ionic liquids. Based on a literature survey, this review summarizes the recent polarity scales of ionic liquids according to the following 4 classes: (1) equilibrium and kinetic rate constants of chemical reactions; (2) empirical polar parameters of ionic liquids; (3) spectral properties of probe molecules; (4) multiparameter approaches. In addition, their interrelations are presented. A systematic understanding of the relationship between different polarity parameters of ionic liquids is of great importance for finding a universal set of parameters that can be used to predict the polarities of ionic liquids quantitatively. The potential utilization of the electron paramagnetic resonance in this field is also addressed.

[Abstract] ( 130 ) [PDF 518 KB] ( 183 )  [Supporting InformationDOI: 10.1007/s11426-016-5579-y
Published Online: 2016-03-23
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Visualization of a1-adrenergic receptors with phenylpiperazine-based fluorescent probes
Yuxing Lin, Wenhua Li, Qinying Yu, Xinyang Zhou, Wei Zhang, Lupei Du, Minyong Li

Several novel fluorescent probes targeting α1-adrenergic receptors were well designed and synthesized by conjugating phenyl- piperazine pharmacophore with coumarin and fluorescein fluorophores. These compounds showed suitable fluorescence property, high receptor affinity, and low cytotoxicity. Moreover, the cell imaging results displayed that these probes can be effective tools for the real-time detection of ligand-receptor interactions, as well as the visualization and location of α1-adrenergic receptors in living cells.

[Abstract] ( 83 ) [PDF 537 KB] ( 163 )  [Supporting InformationDOI: 10.1007/s11426-015-5503-x
Published Online: 2016-03-18
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Recent progress in gold nanoparticle-based biosensing and cellular imaging
Haiyang Peng, Hao Tang, Jianhui Jiang

Gold nanoparticles (AuNPs) have been extensively used in optical biosensing and bioimaging due to the unique optical properties. Biological applications including biosensing and cellular imaging based on optical properties of AuNPs will be reviewed in the paper. The content will focus on detection principles, advantages and challenges of these approaches as well as recent advances in this field.

[Abstract] ( 186 ) [PDF 1870 KB] ( 253 )  [Supporting InformationDOI: 10.1007/s11426-016-5570-7
Published Online: 2016-03-16
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A self-catalytic role of methanol in PNP-Ru pincer complex catalysed dehydrogenation
Yuan-Ye Jiang, Zheng-Yang Xu, Hai-Zhu Yu, Yao Fu

Extracting hydrogen from methanol is a safe and cost-efficient strategy for fuel supply. This process was realized recently at a mild condition with excellent efficiency by ruthenium pincer catalysts. Despite the experimental success, the associated mechanism remains under debate. With the aid of density functional theory (DFT) calculations, an updated and self-consistent mechanism which involves MeOH-catalysed dehydrogenation of ruthenium hydride intermediate and pre-protonation of the pincer ligand was present herein. This mechanism is kinetically favoured over the previously-proposed water-or formicacid-participated ones and more consistent with the optimal experimental condition where strong base and neat methanol solvent are used.

[Abstract] ( 158 ) [PDF 941 KB] ( 182 )  [Supporting InformationDOI: 10.1007/s11426-015-5525-4
Published Online: 2016-03-15
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Pebax®/TSIL blend thin film composite membranes for CO2 separation
Zhongde Dai, Lu Bai, Karoline Nåvik Hval, Xiangping Zhang, Suojiang Zhang, Liyuan Deng

In this study a thin film composite (TFC) membrane with a Pebax/Task-specific ionic liquid (TSIL) blend selective layer was prepared. Defect-free Pebax/TSIL layers were coated successfully on a polysulfone ultrafiltration porous support with a polydimethylsiloxane (PDMS) gutter layer. Different parameters in the membrane preparation (e.g. concentration, coating time) were investigated and optimized. The morphology of the membranes was studied by scanning electron microscopy (SEM), while the thermal properties and chemical structures of the membrane materials were investigated by thermo-gravimetric analyzer (TGA), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The CO2 separation performance of the membrane was evaluated using a mixed gas permeation test. Experimental results show that the incorporation of TSIL into the Pebax matrix can significantly increase both CO2 permeance and CO2/N2 selectivity. With the presence of water vapor, the membrane exhibits the best CO2/N2 selectivity at a relative humidity of around 75%, where a CO2 permeance of around 500 GPU and a CO2/N2 selectivity of 46 were documented. A further increase in the relative humidity resulted in higher CO2 permeance but decreased CO2/N2 selectivity. Experiments also show that CO2 permeance decreases with a CO2 partial pressure increase, which is considered a characteristic in facilitated transport membranes.

[Abstract] ( 145 ) [PDF 1119 KB] ( 161 )  [Supporting InformationDOI: 10.1007/s11426-016-5574-3
Published Online: 2016-03-15
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Coexistence of metamagnetism and single chain magnet behavior in a Fe2Co layer compound
Wenjing Jiang, Yanjuan Zhang, Chengqi Jiao, Liang Zhao, Jixiang Hu, Junli Wang, Tao Liu

A cyanide-bridged Fe2Co double zigzag chain, {[Fe(bipy)(CN)4]2Co(btab)2}n[bipy=2, 2'-bipyridine, btab=4, 4'-(1, 3-phenylene)-bis-4H-1, 2, 4-triazole](1), was obtained with tetracyanometalate precursors and Co ions.The chains were further linked by the ditopic btab ligands to a layer.Magnetic property studies demonstrate that 1 shows both metamagnetism with a critical field Hc=400 Oe and single-chain magnet behavior.

[Abstract] ( 115 ) [PDF 838 KB] ( 119 )  [Supporting InformationDOI: 10.1007/s11426-016-5562-7
Published Online: 2016-03-11
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Adsorption behaviors of strontium using macroporous silica based hexagonal tungsten oxide
Xiaoxia Zhang, Yan Wu, Hao Wu, Yuezhou Wei

A novel macroporous silica-based hexagonal tungsten oxide(h-WO3/SiO2) with exchangeable sodium cations located in hexagonal tunnel structure was synthesized by a facile hydrothermal treatment of sodium tungstate dihydrate with 1 mol/L HCl solution.Utilization of the h-WO3/SiO2 adsorbent to remove aqueous strontium was investigated under the condition of various pH values, contact time, the initial concentration of metal ions, salt ion concentration, and coexisting ions.According to the experimental data, Sr2+ adsorption equilibrium was achieved within 15 min in acidic solution, and the maximum removal capacity of Sr2+ occurred at pH 4.The kinetic adsorption of Sr2+ on h-WO3/SiO2 was controlled by pseudo second-order model, and the saturated adsorption of Sr2+ on h-WO3/SiO2 was better described by Langmuir and Redlich-Peterson isotherm models compared with the Freundlich isotherm model.The distribution coefficient of Sr2+ was more than 2000 cm3/g in the presence of Ca2+, Mg2+, La3+, and Eu3+, indicating that the h-WO3/SiO2 showed excellent selectivity towards Sr2+ in pH 4.

[Abstract] ( 92 ) [PDF 846 KB] ( 136 )  [Supporting InformationDOI: 10.1007/s11426-015-5553-0
Published Online: 2016-03-11
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Easily prepared and stable functionalized magnetic ordered mesoporous silica for efficient uranium extraction
Wenlu Guo, Changming Nie, Lin Wang, Zijie Li, Lin Zhu, Liuzheng Zhu, Zhentai Zhu, Weiqun Shi, Liyong Yuan

Functionalized magnetic Fe3O4@SiO2 composite nanoparticles were prepared by simply embedding iron oxide nanoparticles into MCM-41 through one-step synthesis process, followed by aminopropyls grafting on the mesopore channels, aiming to efficiently and conveniently uptake U(VI) from aqueous solution.The resultant material possesses highly ordered mesoporous structure with large surface area, uniform pore size, excellent thermal stability, quick magnetic response, and desirable acids resistance, confirmed by Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), N2 adsorption/desorption experiments, powder X-ray diffraction(PXRD), and thermogravimetric analysis(TGA).Detailed U(VI) sorption test indicated that this material is indeed an effective U(VI) sorbent with fast sorption kinetics of less than 2 h, large sorption capacity of 160 mg/g at pH 5.0±0.1, and desirable selectivity towards U(VI) ions over a range of competing metal ions.The absorbed U(VI) can be easily desorbed by 0.01 mol/L or more concentrated HNO3 solution, and the reclaimed sorbent can be reused with no obvious decrease of sorption capacity even after 4 sorption-desorption cycles.The present results suggest the vast opportunities of this kind of magnetic composite on the solid-phase extraction of U(VI).

[Abstract] ( 173 ) [PDF 1049 KB] ( 136 )  [Supporting InformationDOI: 10.1007/s11426-016-5561-8
Published Online: 2016-03-11
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The electrochemical stability of ionic liquids and deep eutectic solvents
Qingbo Li, Jingyun Jiang, Guofeng Li, Wancheng Zhao, Xinhui Zhao, Tiancheng Mu

Room temperature ionic liquids (ILs) composed of cations and anions, as well as deep eutectic solvents (DESs) composed of hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs), are regarded as green solvents due to their low volatility. They have been used widely for electrochemically driven reactions because they exhibit high conductivity and excellent electrochemical stability. However, no systematic investigations on the electrochemical potential windows (EPWs), which could be used to characterize the electrochemical stability, have been reported. In this regard, the EPWs of 33 ILs and 23 DESs have been studied utilizing cyclic voltammetry (CV) method and the effects of structural factors (cations and anions of ILs, and HBDs and HBAs of DESs) and external factors (electrode, water content) on the EPWs have been comprehensively investigated. The electrochemical stability of selected ILs comprising five traditional cations, namely imidazolium, pyridinium, pyrrolidinium, piperidinium and ammonium and 13 kinds of versatile anions was studied. The results show that for ILs, both cation and anion play an important role on the reductive and oxidative potential limit. For a same IL at different working electrode, for example, glassy carbon (GC), gold (Au) and platinum (Pt) electrode, the largest potential window is almost observed on the GC working electrode. The investigations on the EPWs of choline chloride (ChCl), choline bromide (ChBr), choline iodide (ChI), and methyl urea based DESs show that the DES composed of ChCl and methyl urea has the largest potential window. This work may aid the selection of ILs or DESs for use as a direct electrolyte or a solvent in electrochemical applications.

[Abstract] ( 175 ) [PDF 548 KB] ( 185 )  [Supporting InformationDOI: 10.1007/s11426-016-5566-3
Published Online: 2016-03-10
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Effect of polyamide on selectivity of its supported Raney Ni catalyst
Haibin Jiang, Shuliang Lu, Xiaohong Zhang, Baoliang Tian, Hui Peng, Wei Dai, Jinliang Qiao

A newly-developed polyamide supported Raney Ni catalyst,which is suitable for use in fix-bed reactions with high selectivity,was studied in this paper.Selective hydrogenation of acetone to isopropanol was chosen as a probe reaction.It has been found that clean preparation of isopropanol could be achieved,that is to say,the two main byproducts(isopropyl ether and methyl-iso-butyl carbinol) could be eliminated with the newly-developed polyamide supported Raney Ni catalyst.The elimination of these side reactions was attributed to the adsorption effect of polyamide support and a model was proposed.The proposed model was further proved by hydroamination reaction of acetone.According to this model,catalyst support can play an important role in chemical reactions.Different products could be produced when different catalyst support is used,the main reaction and side reactions can even be reversed sometimes when the chemicals,active component of catalyst and reaction condition are the same.This model could help to improve catalytic selectivity of many Raney metal catalysts used routinely in chemical and oil refining industry,and is also useful for hydrogenation reactions in pharmaceutical and food industry.

[Abstract] ( 107 ) [PDF 628 KB] ( 101 )  [Supporting InformationDOI: 10.1007/s11426-015-5541-4
Published Online: 2016-03-09
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Affinity-guided protein conjugation:the trilogy of covalent protein labeling, assembly and inhibition
Yongsheng Yu, Jiang Xia

Specific and dynamic biological interactions pave the blueprint of signal networks in cell.For example,a great variety of specific protein-ligand interactions define how intracellular signals flow.Taking advantage of the specificity of these interactions,we postulate an "affinity-guided covalent conjugation" strategy to lock binding ligands through covalent reactions between the ligand and the receptor protein.The presence of a nucleophile close to the ligand binding site of a protein is sine qua none of this reaction.Specific noncovalent interaction of a ligand derivative(which contains an electrophile at a designed position) to the ligand binding site of the protein brings the electrophile to the close proximity of the nucleophile.Subsequently,a conjugation reaction spontaneously takes place between the nucleophile and the electrophile,and leads to an intermolecular covalent linkage.This strategy was first showcased in coiled coil peptides which include a cysteine mutation at a selected position.The short peptide sequence was used for covalent labeling of cell surface receptors.The same strategy was then used to guide the design of a set of protein Lego bricks for covalent assembly of protein complexes of unnatural geometry.We finally made "reactive peptides" for natural adaptor proteins that play significant roles in signal transduction.The peptides were designed to react with a single domain of the multidomain adaptor protein,delivered into the cytosol of neurons,and re-directed the intracellular signal of neuronal migration.The trilogy of protein labeling,assembly,and inhibition of intracellular signals,all through a specific covalent bond,fully demonstrated the generality and versatility of "affinity-guided covalent conjugation" in various applications.

[Abstract] ( 156 ) [PDF 758 KB] ( 171 )  [Supporting InformationDOI: 10.1007/s11426-016-5571-6
Published Online: 2016-03-09
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Multicolor electrochemiluminescence of core-shell CdSe@ZnS quantum dots based on the size effect
Qi-Le Li, Shou-Nian Ding

Multicolor electrochemiluminescence(ECL) of semiconductor nanocrystals tuned by size effect has been successfully achieved using quantum dots(QDs) with core-shell structure for the first time. It would open a new way and provide a guidance for design and preparation of stable and strong multicolor ECL emitters for simultaneous multicomponent analysis application.

[Abstract] ( 134 ) [PDF 973 KB] ( 157 )  [Supporting InformationDOI: 10.1007/s11426-016-5576-1
Published Online: 2016-03-04
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Polyoxometalate-based ionic liquids-promoted CO2 conversion
Mei-Yan Wang, Ran Ma, Liang-Nian He

Polyoxometalates(POMs) are a class of molecular metal oxides, showing numerous applications in various chemical processes due to their unique acid/base and redox features. By adjusting the tunable molecular structures of the anions and counter cations, plenty of POM-based ionic liquids(POM-based ILs) have been fabricated to be used in various fields, such as catalysis, structural chemistry and material science. As a class of excellent catalysts, POM-based ILs have shown advantages in the emerging field of CO2 utilization such as CO2 capture, cycloaddition of CO2 to epoxides, and reduction of CO2, owing to the efficient activation of CO2 by POM anions. This review summarizes recent advances in the catalysis of POM-based ILs, and particularly highlights the areas that are related to CO2 conversion.

[Abstract] ( 202 ) [PDF 854 KB] ( 182 )  [Supporting InformationDOI: 10.1007/s11426-016-5560-9
Published Online: 2016-03-04
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Theoretical simulation of chromatographic separation based on random diffusion in the restricted space
Jianwei Zhao, Yinlu Sun, Yajun Gao

The diffusion behavior of particles in the chromatography is a fundamental issue of chromatographic dynamics. The under-standing of the diffusion behaviors is particularly critical to optimize the operation conditions, improve the chromatographic performance and design a new separation device. Many of the present simulations focus on chromatographic thermodynamics, and very few aim at the overall diffusion and separation process. In order to dynamically trace the trajectory of the diffusing particles and to perform simulations of the whole chromatographic process, we have developed a model based on the framework of random walk in the restricted space and performed the simulation of a single particle diffusion in the gas chromatography. The simulation parameters were determined by comparing with the experimental data. The elution profiles of n-alkanes under different flow rates were accurately simulated with the method. The results show that the relative difference between the measures and the simulations are less than 2% and 10% for the retention time and the peak width, respectively. The simulation method shows great significance for the optimization of separation conditions and the development of novel technologies of chromatographic separation.

[Abstract] ( 129 ) [PDF 770 KB] ( 159 )  [Supporting InformationDOI: 10.1007/s11426-016-5565-4
Published Online: 2016-03-03
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Simultaneous determination of Repaglinide and Irbesartan in biological plasmas using micellar enhanced excitation-emission matrix fluorescence coupled with ATLD method
Haiyan Fu, Hedong Li, Mei Shao, Tianming Yang, Xu Zhang, Rujing Xu, Yujuan Wei, Shuhua Chen, Chuang Ni, Hailong Wu

A highly sensitive and selective 3D excitation-emission fluorescence method has been proposed to rapidly quantify the combined antidiabetics Repaglinide (Re) and Irbesartan (Ir) in rat and human plasmas with the aid of second-order calibration method based on alternating trilinear decomposition (ATLD) method. Re and Ir with weak fluorescence can be endowed with strong fluorescent property by changing the microenvironment in samples and improving the fluorescence quantum yield by using an appropriate micellar enhanced surfactant. The enhanced excitation-emission matrix fluorescence of Re and Ir can be accurately resolved and can simultaneously attain the optimal concentration even in the presence of a potentially strong intrinsic fluorescence from complex biological matrices, such as rat and human plasmas, by using the ATLD method, which completely exploits the “second-order advantage”. The average recoveries of Re and Ir obtained from ATLD with the factor number of 3 (N=3) were 101.0%±4.3% and 99.1%±4.1% for rat plasma and 100.5%±5.4% and 97.1%±3.6% for human plasma. Several statistical methods, including Student’s t-test, figures of merit, and elliptical joint confidence region, have been utilized to evaluate the accuracy of the proposed method. Results show that the developed method can maintain second-order advantage in simultaneous determinations of the weak fluorescent analytes of interest in different biological plasma matrices.

[Abstract] ( 142 ) [PDF 1120 KB] ( 330 )  [Supporting InformationDOI: 10.1007/s11426-016-5569-0
Published Online: 2016-03-02
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Sensitive detection of DNA methyltransferase activity based on supercharged fluorescent protein and template-free DNA polymerization
Daiqi Li, Guoyan Lu, Chunyang Lei, Zhen Wang, Lijun Li, Zhou Nie, Yan Huang, Shouzhuo Yao

DNA methylation, catalyzed by DNA methyltransferases (MTases), is a key component of genetic regulation, and DNA MTases have been regarded as potential targets in anticancer therapy. Herein, based on our previously developed DNA-mediated supercharged green fluorescent protein (ScGFP)/graphene oxide (GO) interaction, coupled with methylation-initiated template-free DNA polymerization, we propose a novel fluorescence assay strategy for sensitive detection of DNA MTase activity. A hairpin DNA with a methylation-sensitive site and an amino-modified 3' terminal (DNA-1) was designed and worked as a starting molecule. In the presence of DNA MTase, methylation-sensitive restriction endonuclease, and terminal deoxynucleotidyl transferase (TdT), DNA-1 can be sequentially methylated, cleaved, and further elongated. The resulting long DNA fragments quickly bind with ScGFP and form the ScGFP/DNA nanocomplex. Such nanocomplex can effectively protect ScGFP from being adsorbed and quenched by GO. Without the methylation-initiated DNA polymerization, the fluorescence of ScGFP will be quenched by GO. Thus, the DNA MTase activity, which is proportional to the amount of DNA polymerization products, can be measured by reading the fluorescence of ScGFP/GO. The method was successfully used to detect the activity of DNA adenine methylation (Dam) MTase with a wide linear range (0.1-100 U/mL) and a low detection limit of 0.1 U/mL. In addition, the method showed high selectivity and the potential to be applied in a complex sample. Furthermore, this study was successfully extended to evaluate the inhibition effect of 5-fluorouracil on Dam MTase activity and detect TdT activity.

[Abstract] ( 131 ) [PDF 826 KB] ( 213 )  [Supporting InformationDOI: 10.1007/s11426-016-5564-5
Published Online: 2016-03-02
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Titanium dioxide-tetra sulphonatophenyl porphyrin nanocomposites for target cellular bio-imaging and treatment of rheumatoid arthritis
Chunqiu Zhao, Fawad Ur Rehman, Hui Jiang, Matthias Selke, Xuemei Wang, Chong-Yang Liu

Photodynamic therapy (PDT) is one of the latest biomedical technologies used for treatment of various neoplastic and non-neoplastic diseases. However, there still exist some well-known problems regarding its efficacy, e.g. effective concentration of the drug at the desired sites, the irradiation light dosimetry and biocompatibility of the photosensitizer. The introduction of nanotechnology and nanomaterial like biocompatible nano-titania (i.e., nano-TiO2) may facilitate to solve some of these problems. In this study we have explored the possibility of combining tetra sulphonatophenyl porphyrin (TSPP) with nano-titania (PT) for efficient PDT with least adverse effects. The spectroscopic properties of these nano-composites were characterized by using fluorescence and UV-Vis absorption spectroscopic study. The singlet oxygen quantum yield was determined by using 2,5-diphenyl-3,4-benzofuran (DPBF), while the effect of nano TiO2 with TSPP on the synovial fibroblast cells from human (HSC) and rat models (RSC) were investigated by confocal laser microscopy and 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay. Our results suggest that nano TiO2 with TSPP can be readily utilized for effective PDT treatment of Rheumatoid Arthritis (RA).

[Abstract] ( 140 ) [PDF 835 KB] ( 198 )  [Supporting InformationDOI: 10.1007/s11426-016-5568-1
Published Online: 2016-03-02
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Regulating sulfur removal efficiency of fuels by Lewis acidity of ionic liquids
Yi Nie, Yuxiao Dong, Hongshuai Gao, Xiangping Zhang, Suojiang Zhang

It is urgent to develop a new deep desulfurization process of fuels as the environmental pollution increases seriously. In this work, a series of Lewis acidic ionic liquids (ILs) [C43MPy]Cl/nZnCl2 (n=1, 1.5, 2, 3) were synthesized and used in extraction and catalytic oxidative desulfurization (ECOD) of the fuels. The effects of the Lewis acidity of ILs, the molar ratio of H2O2/sulfur, temperatures, and different substrates including dibenzothiophene (DBT), benzothiophene (BT) and thiophene (TS), on sulfur removal were investigated. The results indicated that [C43MPy]Cl/3ZnCl2 presented near 100% DBT removal of model oil under conditions of 323 K, H2O2/DBT molar ratio 6:1. Kinetics for the removal of DBT, BT and TS by the [C43MPy]Cl/3ZnCl2-H2O2 system at 323 K is first-order with the apparent rate constants of 1.1348, 0.2226 and 0.0609 h-1, and the calculated apparent activation energies for DBT, BT and TS were 61.13, 60.66, and 68.14 kJ/mol from 298 to 308 K, respectively. After six cycles of the regenerated [C43MPy]Cl/3ZnCl2, the sulfur removal had a slight decrease. [C43MPy]Cl/ 3ZnCl2 showed a good desulfurization performance under optimal conditions.

[Abstract] ( 94 ) [PDF 523 KB] ( 322 )  [Supporting InformationDOI: 10.1007/s11426-016-5563-6
Published Online: 2016-02-22
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Significant enhancement of crystallization kinetics of polylactide in its immiscible blends through an interfacial effect from comb-like grafted side chains
Yin Chen, Yaqiong Zhang, Feng Jiang, Junyang Wang, Zhaohua Xu, Zhigang Wang

A significant enhancement in isothermal crystallization kinetics of biodegradable polylactide (PLA) in its immiscible blends can be accomplished through blending it with a comb-like copolymer. PLA was blended with poly(ethylene glycol) methyl ether acrylate (PEGA) and poly[poly(ethylene glycol) methyl ether acrylate] (PPEGA, a comb-like copolymer), respectively. The results measured from phase contrast optical microscopy (PCOM) and differential scanning calorimetry (DSC) indicate that PLA and PEGA components are miscible, whereas PLA and PPEGA components are immiscible. The study of crystallization kinetics for PLA/PEGA and PLA/PPEGA blends by means of polarized optical microscopy (POM) and DSC indicates that both PEGA and PPEGA significantly increase the PLA spherulitic growth rates, G, although PLA/PPEGA blends are immiscible and the glass transition temperatures of PLA only have slight decreases. PPEGA component enhances nucleation for PLA crystallization as compared with PEGA component owing to the heterogeneous nucleation effect of PPEGA at the low composition of 20 wt%, while PLA crystallization-induced phase separation for PLA/PEGA blend might cause further nucleation at the high composition of 50 wt%. DSC measurement further demonstrates that isothermal crystallization kinetics can be relatively more enhanced for PLA/PPEGA blends than for PLA/PEGA blends. The “abnormal” enhancement in G for PLA in its immiscible blends can be explained by local interfacial interactions through the densely grafted PEGA side chains in the comb-like PPEGA, even though the whole blend system (PLA/PPEGA blends) represents an immiscible one.

[Abstract] ( 138 ) [PDF 1544 KB] ( 281 )  [Supporting InformationDOI: 10.1007/s11426-015-5515-6
Published Online: 2016-01-21
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C-H allylation of N-aryl-tetrahydroisoquinolines by merging photoredox catalysis with iodide catalysis
Zhujia Feng, Tingting Zeng, Jun Xuan, Yunhang Liu, Liangqiu Lu, Wenjing Xiao

A dual catalytic system, combing visible light photoredox catalysis and iodide catalysis, has been developed for the function-alization of inert C-H bonds. By doing so, radical allylation reactions of N-aryl-tetrahydroisoquinolines (THIQs) were realized under extremely mild conditions, affording a wide variety of allyl-substituted THIQs in up to 78% yields.

[Abstract] ( 173 ) [PDF 692 KB] ( 249 )  [Supporting InformationDOI: 10.1007/s11426-015-5548-x
Published Online: 2016-01-08
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Flexible and stretchable electrodes for next generation polymer electronics: a review
Dustin Chen, Jiajie Liang, Qibing Pei

Transparent conductive electrodes play a significant role in the fabrication and development of optoelectronic devices. As next generation optoelectronic devices tend towards mobile and wearable devices, the added attribute of flexibility or stretchability for these electrodes becomes increasingly important. However, mechanical requirements aside, transparent conductive electrodes must still retain high transparency and conductivity, with the metrics for these parameters being compared to the standard, indium tin oxide. In the search to replace indium tin oxide, two materials that have risen to the forefront are carbon nanotubes and silver nanowires due to their high transparency, conductivity, mechanical compliance, and ease of fabrication. This review highlights recent innovations made by our group in electrodes utilizing carbon nanotubes and silver nanowires, in addition to the use of these electrodes in discrete devices and integrated systems.

[Abstract] ( 176 ) [PDF 2389 KB] ( 284 )  [Supporting InformationDOI: 10.1007/s11426-015-5520-9
Published Online: 2016-01-07
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The scaling behavior of the second virial coefficient of linear and ring polymer
Bing Li, Zhaoyan Sun, Lijia An, Zhen-Gang Wang

The scaling behavior of the second virial coefficient of ring polymers at the theta temperature of the corresponding linear polymer (qL) is investigated by off-lattice Monte Carlo simulations. The effects of the solvents are modeled by pairwise interaction between polymer monomers in this approach. Using the umbrella sampling, we calculate the effective potential U(r) between two ring polymers as well as the second virial coefficient A2 of ring polymers at qL, which results from a combination of 3-body interactions and topological constraints. The trend in the strength of the effective potential with respect to chain length shows a non-monotonic behavior, differently from that caused only by topological constraints. Our simulation suggests that there are three regimes about the scaling behavior of A2 of ring polymers at qL: 3-body interactions dominating regime, the crossover regime, and the topological constraints dominating regime.

[Abstract] ( 89 ) [PDF 665 KB] ( 168 )  [Supporting InformationDOI: 10.1007/s11426-015-5531-6
Published Online: 2015-12-30
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Imaging cellular distribution of fluorescent supramolecular nanofibers
Jingyu Wang, Jing Zheng, Yanbin Cai, Jinxin Zheng, Jie Gao, Qingqiu Gong, Zhimou Yang

In this study, we used the 4-nitro-2,1,3-benzoxadiazole (NBD) as an aromatic capping group for a peptide to construct the supramolecular nanofibers. Taking the advantage of the fluorescence property of NBD, we could directly observe the cellular distribution of the self-assembled nanofibers. We found that the distributions of the nanofibers of NBD-FFETIGGY are different in four mammalian cells and two plant cells. The nanofibers are mainly located at the surface of two mammalian cells and one plant cell, while in the intracellular space of other cells. Different distributions of nanofibers lead to different protein binding patterns of the nanofibers in two different cell lines. We believe that a useful and versatile platform has been offered to the image cellular distribution of nanofibers, which can provide useful information to the biological functions of the self-assembled nanostructures.

[Abstract] ( 120 ) [PDF 1196 KB] ( 109 )  [Supporting InformationDOI: 10.1007/s11426-015-5521-8
Published Online: 2015-12-11
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Effect of glutathione on in vivo biodistribution and clearance of surface-modified small Pd nanosheets
Yizhuan Huang, Xiaolan Chen, Saige Shi, Mei Chen, Shaoheng Tang, Shiguang Mo, Jingping Wei, Nanfeng Zheng

Plasmonic Pd nanosheets have been emerging as promising materials for applying in near-infrared (NIR) photothermal therapy (PTT) of cancer. However, animal in mice studies indicated that the original synthesized poly(vinylpyrrolidone) (PVP)-protected small Pd nanosheets (Pd-PVP) and some further surface-modified small Pd nanosheets such as Pd-PEG(SH) easily accumulated in reticuloendothelial system (RES) organs (liver, spleen, etc.) and were difficult to be cleared from these organs quickly. In the work, we surprisingly found that glutathione (GSH) could promote the clearance of surface-modified small Pd nanosheets (e.g. Pd-PVP, Pd-PEG(SH) and Pd-GSH) from the RES organs efficiently. The effects of GSH on the bio- distribution and clearance of different surface-modified Pd nanosheets were investigated. Our results indicated that these surface-modified Pd nanosheets with or without GSH added caused no morbidity at target primary organs, and GSH can promote the clearance of different surface-modified Pd nanosheets in the order of Pd-PVP≈Pd-PEG(SH)>Pd-GSH. This study suggests that glutathione could be an attractive reagent for promoting nanomaterials eliminated from the reticuloendothelial systems (RES).

[Abstract] ( 218 ) [PDF 964 KB] ( 187 )  [Supporting InformationDOI: 10.1007/s11426-015-5422-x
Published Online: 2015-05-13
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Ru(Ⅱ)-catalyzed ortho-amidation and decarboxylation of aromatic acids: a versatile route to meta-substituted N-aryl benzamides
Xian-Ying Shi, Xue-Fen Dong, Juan Fan, Ke-Yan Liu, Jun-Fa Wei, Chao-Jun Li

Carboxylate as a promising and valuable directing group has attracted a great deal of attention. However, employing it as a traceless direction group has rarely been reported. We developed the ruthenium-catalyzed amidation of substituted benzoic acids with isocyanates via directed C-H functionalization followed by decarboxylation to afford the corresponding meta-substituted N-aryl benzamides, in which the carboxylate serves as a unique, removable directing group. Notably, this protocol can provide an efficient alternative to access meta-substituted N-aryl benzamides, which are much more difficult to prepare than ortho-substituted analogues.

[Abstract] ( 0 ) PDF (0 KB) ( 0 )  [Supporting InformationDOI: 10.1007/s11426-015-5364-3
Published Online: 2015-03-20
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Dithienocarbazole-and benzothiadiazole-based donor-acceptor conjugated polymers for bulk heterojunction polymer solar cells
Ziqing Rong, Yunfeng Deng, Zhiyuan Xie, Yanhou Geng, Fosong Wang

Donor-acceptor (D-A)-conjugated polymers P(BT-C1) and P(BT-C2), with dithieno[2,3-b;7,6-b]carbazole (C1) or dithieno[3,2-b;6,7-b]carbazole (C2) as D-unit and benzothiadiazole (BT) as A-unit, were synthesized. The optical bandgaps of the polymers are similar (1.84 and 1.88 eV, respectively). The structures of donor units noticeably influence the energy levels and backbone curvature of the polymers. P(BT-C1) shows a large backbone curvature; its highest occupied molecular orbital (HOMO) energy level is -5.18 eV, whereas P(BT-C2) displays a pseudo-straight backbone and has a HOMO energy level of -5.37 eV. The hole mobilities of the polymers without thermal annealing are 1.9×10-3 and 2.7×10-3 cm2V-1s-1 for P(BT-C1) and P(BT-C2), respectively, as measured by organic thin-film transistors (OTFTs). Polymer solar cells using P(BT-C1) and P(BT-C2) as the donor and phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor were fabricated. Power conversion efficiencies (PCEs) of 4.9% and 5.0% were achieved for P(BT-C1) and P(BT-C2), respectively. The devices based on P(BT-C2) exhibited a higher Voc due to the deeper HOMO level of the polymer, which led to a slightly higher PCE.

[Abstract] ( 221 ) [PDF 1104 KB] ( 418 )  [Supporting InformationDOI: 10.1007/s11426-014-5221-9
Published Online: 2014-12-29
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Trimer formation of 6-methyl-1,3,5-triazine-2,4-diamine in salt with organic and inorganic acids: analysis of supramoleculararchitecture
XIAO ZhenYu, WANG WenQiang, XUE RuiYu, ZHAO Lei, WANG Lei, ZHANG YiHeng

Although the numbers of co-crystals, salts, polymorphs, hydrates, and solvates are growing steadily, trimers that contain both inorganic and organic acids are still very rare in the Cambridge Structural Database (CSD). When 3,5-dihydroxybenzoic acid was crystallized readily with 6-methyl-1,3,5-triazine-2,4-diamine in a 4:3 ratio of ethanol and water by adding a few drops of nitric acid upon slow evaporation in ambient conditions, 6-methyl-1,3,5-triazine-2,4-diamine and 3,5-dihydroxybenzoic acid with the nitric acid form of 1:1:1 an inorganic-organic salt formulated as [(C4H8N5+)·(NO3-)·(C7H6O4)]. The supramolecular architecture, which is quite elegant and simple, appeared as stacking of a 3D network in adduct. Proton transfer from the HNO3 to 6-methyl-1,3,5-triazine-2,4-diamine N acceptor (triazine N) occurred in the organic salt and led to the ionic heterosynthon in the structure. Cooperation among the -COOH, -OH, NO3-, and -NH- functional groups for the observed hydrogen bond synthon was examined in the structure. In adduct, recognition among the constituents is established through N-H…O, O-H…N, and O-H…O hydrogen bonds. The agomelatine molecules are linked through the intermolecular hydrogen bonding interactions (O-H…O) to form a 1D chain. In addition, the nitric acid anions and base cations act as donors and acceptors of hydrogen bonds and interlink, almost to co-planarity, the hydrogen-bonded chains through interchain N-H…O, O-H…N, as well as O-H…O interactions into a 2D sheet structure. Persistent N-H…O interactions were found to play an important role in the formation of the final 3D array. The salt was characterized by elemental analysis, IR, thermogravimetric analysis, and single- crystal X-ray diffraction, to better understand how intermolecular interactions influence its supramolecular assembly.

[Abstract] ( 148 ) [PDF 1520 KB] ( 330 )  [Supporting InformationDOI: 10.1007/s11426-014-5101-3
Published Online: 2014-11-28
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Outgassing analysis of molecular glass photoresists under EUV irradiation
CHEN Li, XU Jian, YUAN Hua, YANG ShuMin, WANG LianSheng, WU YanQing, ZHAO Jun, CHEN Ming, LIU HaiGang, LI ShaYu, TAI RenZhong, WANG ShuangQing, YANG GuoQiang

A device was designed and assembled to analyze the outgassing of molecular glass (MG) photoresists under extreme ultraviolet (EUV) exposure. The outgassing of the photoresists with different components and different concentrations of tert-butoxycarbonyl (t-Boc), photo-generated acid (PAG), and acid quencher was systematically investigated. Based on experiments, some solutions for reducing the outgassing of MG photoresists were proposed.

[Abstract] ( 140 ) [PDF 1878 KB] ( 238 )  [Supporting InformationDOI: 10.1007/s11426-014-5122-y
Published Online: 2014-11-28
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Stereoselective interactions of chiral dipeptides on amylose based chi-ral stationary phases
ALI Imran, HAQUE Ashanul, AL-OTHMAN Zeid A., AL-WARTHAN Abdulrahman, ASNIN Leonid

Dipeptides are stereo-specifically involved in several biological functions that are challenging to separate enantiomerically. Elution order of enantiomers is an important issue in chiral chromatography. Amylose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase (CSP) is the best and most-widely-used CSP in chiral separations, but experimental data of enantiomeric separation of dipeptides on this CSP is lacking. Simulation studies were conducted to determine the order of elution and the chiral recognition mechanism of didpetides on this CSP. Results indicated that the docking energy of SR-enantiomers were higher than SS-antipodes. The range of docking energies for SR-enantiomers was-7.44 to-5.92 kcal/mol with CSP, but-7.15 to-5.87 kcal/mol for SS-stereoisomers. Therefore it is predicted that SS-enantiomer will elute first, followed by SR-antipode. Furthermore, hydrogen bondings, van der Waal's interactions and electrostatic interactions were observed among SR-and SS-enantiomers and chiral grooves of CSP. The number of hydrogen bonds was one in each enantiomer binding except S-Ala-R-Tyr, which contained two hydrogen bonds. No hydrogen bond was found in S-Ala-R-Trp, S-Leu-S-Trp, and S-Leu-S-Tyr dipeptides bindings. The chiral recognition mechanisms dictate different strengths of stereoselective bindings of the enantiomers on CSP.

[Abstract] ( 125 ) [PDF 1241 KB] ( 249 )  [Supporting InformationDOI: 10.1007/s11426-014-5239-z
Published Online: 2014-11-05
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3Department of Biological Chemistry, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
WU ShuaiBin, ZHANG HongFei, YANG KaiGuang, MA JunFeng, LIANG Zhen, ZHANG LiHua, ZHANG YuKui

Fast and efficient sample preparation methods are a prerequisite for protein identification in bottom-up proteomics. Here, an innovative microwave irradiation sample preparation method was developed based on an optimized organic-aqueous solvent system for protein identification. Specifically, protein solutions containing high-concentration acetonitrile were subjected to 5 min microwave irradiation. After cooling down, trypsin was added and the digestion was performed with 30 s microwave ir-radiation, and the resulting peptides were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). A shortened processing time of only 5.5 min is needed with this method (more than 12 h is necessary in the traditional overnight protein sample preparation). Moreover, due to the absence of urea and other chaotropic reagents, the digests can be readily identified by MALDI-TOF MS. When an assessment of this method was performed by digesting a model protein BSA, 69%±3% sequence coverage corresponding to 47±3 peptides was obtained, which shows better protein identification than that from the standard overnight protein sample preparation method (51%±2% sequence coverage and 23±1 peptides). Another model protein α-casein was used for the analysis of protein phosphorylation with the newly developed method that yielded 4 phosphopeptides with 8 phosphorylation sites, whereas 3 phosphopeptides with 2 phosphorylation sites were obtained from the traditional overnight approach. Moreover, the organic-aqueous microwave irradiation method provides effective digestion for proteins down to fmol.

[Abstract] ( 205 ) [PDF 449 KB] ( 349 )  [Supporting InformationDOI: 10.1007/s11426-014-5163-2
Published Online: 2014-10-30
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The hazards of life and the chance to be at the border of different worlds. A subjective view of fifty years in quantum chemistry
ANDRÉ Jean-Marie
[Abstract] ( 130 ) [PDF 686 KB] ( 412 )  [Supporting InformationDOI: 10.1007/s11426-014-5201-0
Published Online: 2014-08-27
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The Ninth Sino-US Chemistry Professors Conference: Frontiers and Challenges in the Rapid Development of Chemistry
[Abstract] ( 205 ) [PDF 498 KB] ( 414 )  [Supporting InformationDOI: 10.1007/s11426-013-5055-x
Published Online: 2014-01-06
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electrodialysis method and the fouling of cation-exchange membrane
BAI Lu, WANG XiaoLiang, NIE Yi, DONG HaiFeng, ZHANG XiangPing, ZHANG SuoJiang

With the wide application of ionic liquids (ILs) in various fields, developing efficient techniques to recover ILs from effluent is an urgent demand for the cost reduction and the environmental protection. In this study, an electrodialysis (ED) method was used to recover 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) IL from aqueous solution as model effluent. The influences of initial IL concentration and applied voltage on the current efficiency, removal ratio, desalination ratio, membrane flux and specific energy consumption during the ED process were investigated. It was found that the removal ratio and desalination ratio increases with the increasing of initial IL concentration and applied voltage. The current efficiency decreases with the increasing of initial IL concentration and the current efficiency reached the maximum value of 94.3% at 25 V. Besides, as the applied voltage increases, the membrane flux increases and the specific energy consumption decreases. Moreover, the fouling of cation-exchange membrane was also discovered after the desalination of IL. The deposits on the surface or into the membrane which is probably caused by [Bmim]+ was characterized by scanning electron microscopy, elemental analysis and Fourier transform infrared.

[Abstract] ( 194 ) [PDF 695 KB] ( 601 )  [Supporting InformationDOI: 10.1007/s11426-013-5016-4
Published Online: 2013-11-11
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