核壳结构Cu@CoW的合成和对硼氨配合物水解的催化性能

分别以硼氨配合物和硼氢化钠为还原剂合成了核壳结构的Cu@CoW三元合金催化剂和非核壳结构的CuCoW三元合金催化剂,25℃下,Cu0.4@Co0.5W0.1三元合金催化剂对于硼氨配合物水解反应的TOF(转换频率)值达到0.369 0 molH2·molcat-1·s-1,明显高于非核壳结构的Cu0.4Co0.5W0.1催化剂,接近Pt、Pd等贵金属的催化活性,反应的活化能为49 kJ·mol-1。与非核壳结构的CuCoW合金相比,核壳结构的Cu@CoW三元合金催化剂的催化性能及稳定性均有明显提高。     

尼龙6纳米纤维膜的制备及其对己烷雌酚的吸附性能研究

采用静电纺丝设备制备尼龙6纳米纤维膜。用静、动态吸附方法,研究了尼龙6纳米纤维膜对己烷雌酚的吸附性能,考察了吸附时间、初始浓度及介质p H值对尼龙6纳米纤维膜吸附己烷雌酚的影响。结果表明,初始浓度为2mg/L时,尼龙6纳米纤维膜吸附己烷雌酚的过程符合准一级动力学模型;当初始浓度在5~20mg/L范围内,吸附过程符合准二级动力学模型。尼龙6纳米纤维膜吸附己烷雌酚的过程符合Freundlich等温吸附模型。     

Colorimetric detection of glucose using a boronic acid derivative receptor attached to unmodifed AuNPs简

A simple, cheap and non-enzymatic colorimetric strategy for glucose detection has been designed based on the interactions between a phenylboronic acid （PBA） derivative, which is coupled with gold nanoparticles （AuNPs） as the colorimetric reporters, and glucose. The PBA-AuNPs hybrid system proposed here exhibits ordered photochemistry behaviors upon the addition of glucose at different pH values. There are two linear regions of glucose concentration for the glucose sensor at different pH values, i.e., between 0.1 mmol/L and 9.8 mmol/L at pH 6 with the detection limit of 64μmol/L and between 0 and 6.5 mmol/L with the detection limit of 48 μmol/L at pH 9, respectively. To test the practicality of the sensor system, we also applied this assay to detect a glucose sample in the artificial saliva.     

Preconcentration of chlorophenols in water samples using threedimensional graphene-based magnetic nanocomposite as absorbent

In this paper, a novel magnetic solid-phase extraction method using three-dimensional graphene-based magnetic nanocomposite as adsorbent for the preconcentration of several chlorophenols from water samples prior to high-performance liquid chromatography analysis was developed. Various experimental parameters were investigated. Under the optimum conditions, the enrichment factors of the method were in the range of 186–312, and the limit of detection(S/N = 3) was 0.10 ng/mL. The recoveries of the method were in the range between 85.1% and 101.2%. The developed method has been successfully applied to the determination of chlorophenols in environmental water samples.     

Exponentially modified Gaussian relevance to the distributions of translocation events in nanopore-based single molecule detection

Nanopore technique plays an important role in single molecule detection, which illuminates the properties of an individual molecule by analyzing the blockage durations and currents. However, the traditional exponential function is lack of efficiency to describe the distributions of blockage durations in nanopore experiments. Herein, we introduced an exponentially modified Gaussian （EMG） function to fit the duration histograms of both simulated events and experimental events. In comparison with the traditional exponential function, our results demonstrated that the EMG provides a better fit while covers the entire range of the distributions. In particular, the fitted parameters of EMG could be directly used to discriminate the sequence length of the oligonucleotides at single molecule level.     

Gold nanoparticles-enhanced bisphenol A electrochemical biosensor based on tyrosinase immobilized onto self-assembled monolayers-modified gold electrode

A novel electrochemical sensor based on the immobilization of tyrosinase(tyr) onto gold nanoparticles(nano-Au) and thioctic acid amide(T-NH2) self-assembled monolayers(SAMs)-modified gold electrode has been developed for the determination of bisphenol A(BPA).It was found that the nano-Au could significantly enhance the electrochemical response of tyr/nano-Au/T-NH2/Au electrode to BPA,and the enhancement effect of nano-Au on the current response was also related to the enzyme.The results indicated that the biosensor could be used as a detector for BPA determination with a linear range from3.99 ×10-7mol/L to 2.34 ×10-4mol/L and a detection limit of 1.33×10-7mol/L.In addition,this biosensor showed good reproducibility.     

Synthesis of N-substituted-2-aminobenzothiazoles using nano copper oxide as a recyclable catalyst under ligand-free conditions in reusable PEG-400 medium

A simple and practical method for the synthesis of N-substituted-2-aminobenzothiazoles via a crosscoupling reaction of 2-iodo anilines with isothiocyanates is envisaged using nano copper oxide as a recyclable catalyst and Cs2CO3as a base in PEG-400,as a bio-degradable,reusable,inexpensive and nontoxic reaction medium,under ligand-free conditions.The present tandem process underlines environmental acceptability to access a wide range of N-substituted-2-aminobenzothiazoles in good to excellent yields.     

The effects of surface ligands and counter cations on the stability of anionic thiolated M12Ag32 （M=Au,Ag） nanoclusters

The stabilities of [M12Ag32（SR）30]4- （M = Ag, Au and SR = SPhF2, SPhCF3, SPhF） clusters having the same structure but different surface ligands or counter cations were systematically studied. It was clearly revealed that a subtle structural change in the surface ligands or counter cations could significantly alter the overall stability of [M12Ag32（SR）30]4 although they all had an electronic structure of 18-electron superatom shell closure. SPhF2 was found as a better surface ligand than SPhCF3 or SPhF to stabilize [M12Ag32（SR）30]4-. And the use of more bulky [（PPhj）2N]＋ as the counter cations was revealed to be more deleterious to the overall stability of [M12Ag32（SR）30]4- clusters than PPh4＋. [Au12Ag32（SR）30]4- was much more stable than [Ag44（SR）30]4 with the same surface ligands and counter cations. An exceptional stability was observed on （PPh4）4[Au12Ag32（SPhF2）30] which was stable in DMF for more than 8 days in air at 80 ℃. More research efforts are still needed to deeply understand why a small structural change could result in a significant change in the stability of noble metal nanoclusters.     

Improving the performance of all-solid-state supercapacitors by modifying ionic liquid gel electrolytes with graphene nanosheets prepared by arc-discharge

Ionic liquid gel polymers have widely been used as the electrolytes in all-solid-state supercapacitors, but they suffer from low ionic conductivity and poor electrochemical performance. Arc discharge is a fast, low-cost and scalable method to prepare multi-layered graphene nanosheets, and as-made graphene nanosheets （denoted as ad-GNSs） with few defects, high electrical conductivity and high thermal stability should be favorable conductive additive materials. Here, a novel ionic liquid gel polymer electrolyte based on an ionic liquid （EM1MNTF2） and an copolymer （P（VDF-HFP）） was modified by the addition of ad-GNSs as an ionic conducting promoter. This modified gel electrolyte shows excellent thermal stability up to 400 ℃ and a wide electrochemical window of 3 V. An all-solid-state supercapacitor based on commercial activated carbon was fabricated using this modified ionic liquid gel polymer electrolyte, which shows obviously improved electrochemical behaviors compared with those of the corresponding all-solid-state supercapacitor using pure ionic liquid gel polymer electrolyte. Specially, smaller internal resistance, higher specific capacitance, better rate performance and cycling stability are achieved. These results indicate that the ionic liquid gel polymers modified by ad-GNSs would be promising and suitable gel electrolytes for high performance all-solid-state electrochemical devices.     

不同聚合物对纳米SiO2表面改性的研究进展

纳米SiO2由于具有无味、无毒、无污染等特性,因而被广泛用作无机纳米填料。纳米SiO2极易团聚,从而限制了它的广泛应用。但纳米SiO2表面富含大量的硅羟基,可对其进行表面改性。纳米SiO2表面改性的方法较多,主要有表面物理改性和表面化学改性两种,其中表面化学改性中又以聚合物改性的效果最好。本文综述了国内外利用不同的聚合物——亲水性、疏水性和两亲性聚合物对纳米SiO2表面的化学改性,并对其应用进行了分析,展望了其发展前景。