新型纳米金修饰玻碳电极对水杨酸的电催化氧化

借助"种子媒介纳米金属生长法"制备新型的纳米金修饰玻碳电极,应用场发射扫描电镜、紫外-可见光谱分析和电化学方法等,研究该电极的表面形貌及其电化学性能.结果表明,该修饰电极对水杨酸的电化学氧化有明显的电催化作用,电极响应灵敏度是裸玻碳电极表面的1.8倍.其氧化峰电流与水杨酸浓度在5.0×10-7~8.0×10-5mol/L范围内呈良好的线性关系,可用于水中痕量水杨酸的检测.     

Gold Nanoparticle-based Colorimetric Sensor for pH Sensing

We present a newly designed colorimetric sensor sensitive to pH value based on a gold nanocomposite composed of gold nanoparticles and pH-sensitive polymer{dodecylthioether end functionalized poly[2-（diethylamino） ethyl methacrylate], poly（DEAEMA）-DDT}. We have shown that this design can produce stable GNP precipitate under weakly basic condition（pH=7.5） and this precipitate can be dispersed in acidic solution（pH=4.0）, due to the 2-（diethylamino） ethyl methacrylate protonated by H＋. The precipitation-dispersion process is reversible and accompanied by distinct color change that are clearly visible to the naked eye. This development may have application in the controlled fabrication of reversible pH-sensitive nanostructures and/or devices.     

Iodine Determination by Microwave Plasma Torch Atomic Emission Spectrometer Coupled with Online Preconcentration Vapor Generation Technique

This article focuses on iodine determination by microwave plasma torch atomic emission spectrometry （MPT-AES） coupled with online preconcentration vapor generation method. A new desolvation device, multistrand Nafion dryer, was used as the substitute for condenser desolvation system. Some experimental conditions, such as preconcentration time, acidity of sample solution, rinsing solution acidity and dynamic linear range were investigated and optimized. The new desolvation system eliminates the problem of decreasing emission intensity of I（I） 206.238 nm line with the increase of working time on a conventional condenser desolvation system, thus greatly improving the reproducibility.     

Effects of Lanthanide Ions on Electrooxidation of Methanol

Four kinds of lanthanide ions（Sm^3＋,Yb^3＋,Eu^3＋,La^3＋）as an additive were added into the aqueous solution containing methanol,respectively,and their effects on methanol elecotrooxidation in aqueous solutions were studied with cyclic voltammetry.The results show that the four kinds of ions have promotion action upon the electrooxidation of methanol to different degrees.The best additive,Sm^3＋,can increase the anodic oxidation current of methanol by 80%and the peak potential shifted negatively about 50 mV.The promotion effects of the lanthanide ions were considered to be related to the extranuclear electron distribution of these ions and their adsorption on the Pt electrode surface.     

Synthesis and Antimicrobial Properties of the Novel Fluonnated Bis-ammonium Salts with Two Primary Amine Groups

In order to resolve the increasing resistance phenomena of the Gram-negative bacteria against single chain quaternary ammonium salts (QAS), lysine with a pedant fluorinated bis-ammonium salts was synthesized and its antimicrobial properties were evaluated in this work. The novel fluorinated bis-ammonium salts shows similar activity with conventional single chain quaternary ammonium salts against Gram-positive bacteria but stronger activity against Gram-negative bacteria and yeast compared with the single chained counterpart.     

PREPARATION AND PROPERTIES OF POLY(LACTIC ACID-CO-GLYCOL TEREPHTHALIC ACID)COPOLYESTER

1. INTRODUCTIONThe amount of industrial and municipal waste has been increasing all over the world. Therefore, the design and development of materials capable of being degraded into safe components under specific environmental conditions have become incre…     

吡啶酮系偶氮染料解离平衡的^15NNMR和IR波谱

报道了四个富氮-15吡啶酮偶氮染料的氮-15核磁共振中β-氮原子的化学位移,研究了氮-15原子和pH值之间的关联.当样品溶液从酸性转成碱性,β-氮-15原子的化学位移从366-380PPM移到500PPM,相应于从腺型到偶氮阴离子结构.根据各种pH值的化学位移可计算腺结构的含量,用IR证实了这一系列化合物的酸碱离解平衡.在酸性或中性条件下,固态化合物的二个羰基吸收,在碱性条件下变成只有一个羰基吸收峰,其它官能团的吸收峰表明了与平衡的位移的相应变化.     

低共熔溶剂及其应用研究进展

作为一类新型的绿色溶剂,低共熔溶剂具有蒸汽压低、无毒性、可生物降解、溶解性和导电性优良、电化学稳定窗口宽等独特的物理化学性质,并且可以通过选择合适的组成和配比来调节其性能,在很多领域中有着诱人的应用前景.本文从低共熔溶剂的组成、性质及其应用等3个方面综述了近年来低共熔溶剂的研究进展,并对目前研究中存在的问题进行了讨论.     

Catalytic combustion of soot particulates over La_(2-x)K_xNiMnO_6 catalysts

Nanosized La2-xKxNiMnO6 catalysts with ABO3 type perovskite-like structure were prepared by auto-combustion method using citric acid as a ligand to control particle size and morphology.The structures and properties of these perovskite-like oxides were investigated by X-ray powder diffraction(XRD)and temperature-programmed reduction(TPR).The catalytic activities for soot combustion were evaluated by temperature- programmed oxidation(TPO)with pure O2 and O2/NOx as oxidant,respectively.In the La2-xKxNiMnO6 catalysts,the partial substitution of K at A-site leads to an increase of the concentrations of high valence cation and oxygen vacancy,which enhance the catalytic activity for soot combustion.The optimal substitution amount of K was equal to x=0.4 among these samples.Tp(peak temperature)in O2-TPO profile was 420-C and Tp in O2/NOx-TPO profile was 370-C over La1.6K0.4NiMnO6 catalyst for soot particulates combustion under loose contact conditions between catalyst and soot.     

Efficient and stable non-doped deep-blue organic light emitting diode based on an anthracene derivative

A new anthracene derivative 9,10-bis[3,5-di(4-tert-butylphenyl)phenyl]anthracene (BPPA) was synthesized via Suzuki coupling reaction and characterized by 1H NMR spectrum,mass spectrum,and elemental analysis.BPPA exhibits deep-blue emission both in solution and in solid thin film.This compound has a non-planar structure that results in high thermal stability and the phenomenon of polymorphism.The non-doped device based on this material shows stable deep-blue emission with the 1931 Commission international de...