基于适配体的纳米金光学探针可视化法快速测定中药材中的啶虫脒

以农药啶虫脒适配体作为识别元件,以纳米金作为颜色指示剂,建立了一种基于啶虫脒适配体的纳米金光学探针特异测定中药材中啶虫脒含量的方法.用甲醇超声提取样品,离心后,上清液用无水MgSO4和N-丙基乙二胺净化.纳米金溶液和啶虫脒适配体溶液在室温下反应15 min后,加入样品溶液,继续反应20 min,最后加入200 mmol...     

纳米金属铜与纳米氧化锌之间相互作用的EPR和XPS研究

由于纳米材料独特的表面效应、电子效应及量子尺寸效应 ,已被广泛应用于各个领域 .有关纳米材料研究的报道很多 [1～ 7] ,大部分是关于纳米材料的制备[1～ 4 ] 及其特性研究 .对于纳米金属及纳米氧化物之间相互作用的研究迄今尚未见报道 .本文采用超声分散和机械研磨法物理混合纳米金属铜粉和纳米氧化锌 ,借助 EPR和 XPS技术对样品进行了表征 ,发现混合体系出现了 Cu2 + 的顺磁信号 ,Zn L3M4 5M4 5俄歇动能和 O1s的电子结合能亦发生了变化 ,表明纳米 Cu0 和纳米 Zn O之间存在相互作用 ,作用形式为 Cu— O—Zn.1　实验部分1 .1　样品…     

稀土掺杂ZnS纳米晶中稀土离子与纳米基质之间的能量传递

以甲基丙烯酸为表面包覆剂在水／醇溶液中合成了ZnS:Eu^3 ,ZnS:Tb^3 纳米晶,用傅里叶变换红外光谱和X射线粉末衍射谱表征了样品的表面与晶型,样品均为立方闪锌矿型,没有出现与稀土离子相关的相;用光致发光和激发谱研究了样品中的发光过程,其中ZnS:Tb^3 纳米晶中存在纳米基质与Tb^3 之间的能量传递,并引起Tb^3 的特征发射。     

软模板法六边形纳米Pd粒子的超声制备与表征

在微量十六烷基三甲基溴化铵(CTAB)存在下,超声还原PdCl₂水溶液,没有气氛保护且不加还原剂制得了纳米Pd粒子,用XRD、TEM、选区电子衍射(SAED)、UV、HRTEM和低温氮吸附-脱附等进行了表征。结果表明,纳米Pd晶粒的粒径分布集中,约为8 nm,呈六边形,(111)晶面的晶面间距为0.22 nm,晶格条纹清晰均匀。研究了纳米粒子的生长过程,揭示了NR₄X-Pd²⁺配合物的生成,分析了可能的超声反应机理。利用CTAB模板控制得到的纳米粒子比未添加CTAB样品的比表面积增大了10 m²·g^-1,有利于催化性能的提高。     

层间距为1.44 nm层状氢氧化苯甲酸锌剥离重组行为研究

层间距为1.44 nm层状氢氧化苯甲酸锌在乙醇、正丙醇、正丁醇介质中可剥离成其基本组成单元纳米层. 用TG-DTA、XRD、SEM、TEM和元素分析等手段研究了剥离的纳米层重组得到样品的结构特征、形貌和化学组成. 结果表明: 水热合成样品和剥离的纳米层重组样品具有相同的层状结构, 它们的化学组成分别为Zn(OH)1.12(C6H5COO)0.88和Zn(OH)1.1(C6H5COO)0.9. 水热合成的纤维状粒子剥离重组后改变成为像纳米带和纳米花粒子形貌.     

纳米Cu和Ag的缺陷研究

使用氢电弧等离子体方法制备纳米Cu和Ag超微粒子,这些粒子在制备过程中自动地高温溶氢.同时使用相近的电源功率的惰性气体蒸发法制备纳米Cu和Ag.分别将各种样品在低温退火,同时使用TEM监测粒子的大小,选择最佳退火温度制成标准样品.使用TEM,HRTEM,XRD线形精炼与Fourier分析方法研究了纳米Cu和Ag中的缺陷.发现了纳米Cu和Ag的x射线衍射线形的非对称性并研究了其物理意义.用Fourier分析方法计算得到纳米Cu和Ag中的孪晶几率.并对于纳米材料中的氢对结构的影响进行了讨论.     

纳米尺度超声显影微囊的制备及性能表征简

采用双乳液-溶剂挥发法制备了内部包封氟碳液体的聚乳酸-甲氧基聚乙二醇两嵌段共聚物(MePEG-b-PLA)基超声显影纳米微囊;用2种不同嵌段比的MePEG-b-PLA共聚物研究共聚物组成与纳米囊性能的关系;选用聚乙烯醇(PVA)、羧甲基葡聚糖(CMG)和壳聚糖(CS) 3种乳化剂对纳米囊表面进行亲水性修饰. 对所制备纳米囊的粒径、Zeta电位、形貌和水溶液稳定性进行了表征. 结果表明,利用质量分数为1%的PVA和质量分数为1%的CMG组成的复配乳化剂和m(MePEG)：m(PLA)= 1：3的聚合物制得的纳米囊的平均粒径为432.9 nm,水溶液稳定性优良. 利用超声仪对纳米囊体外超声显影性能进行研究,结果表明,所得聚乳酸-甲氧基聚乙二醇纳米囊具有更好的中心成像区域灰度值和更持久的体外超声显影效果. 结合3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)比色法研究证实该纳米囊具有低细胞毒性. 在超声影像学领域具有良好的应用前景.     

Cu2+掺杂CdS纳米晶的制备与表征

以巯基乙酸为稳定剂,采用水相合成法制备了Cu2+掺杂的CdS纳米晶. 分别用电感耦合等离子体发射光谱仪、原子力显微镜测试技术对样品的化学成分及形状进行分析表征,研究了掺杂CdS纳米晶的荧光激发与发射光谱. 实验结果表明,在样品制备过程的溶液中回流2 h后,组成为Cd0.99Cu0.01S的样品形状有棒状和粒状2种,Cu2+的掺入使得CdS纳米晶的荧光发射光谱红移,没有掺杂的样品在回流前的最大发射波长在520 nm处,而组成为Cd0.99Cu0.01S和Cd0.98Cu0.02S的样品在回流前的最大发射波长分别为595和610 nm,通过改变Cu与Cd摩尔比可调控CdS纳米晶的发射波长范围.     

超声辅助制备表面修饰纳米Ca2B6O11及表征

纳米材料的制备及其应用于润滑油摩擦性能研究,对于改善油品的性能和延长设备的使用寿命具有重要的意义。首次采用超声辅助法合成了球型、粒径分布均匀的纳米硼酸钙润滑油添加剂并对其进行了表征。XRD结合热分析发现样品在室温下为非晶态,750℃结晶,且原料配比对晶态没有影响。SEM和TEM分析证明在超声波辅助下可以得到50 nm的超微粒子,而不用超声波的样品粒径为200~300 nm。在超声和搅拌下将2%的添加剂均匀分散在润滑油中,得到成品油。静置观察评价了润滑油的分散性和稳定性。在重负荷车辆与工业齿轮油中试验检验了润滑油的的润滑性能。结果表明,纳米硼酸钙添加剂具有良好的分散性、稳定性和抗磨减摩性能。     

超声雾化反应法制备CeO2纳米粉体

以硝酸铈和碳酸氢铵为原料,采用超声雾化反应法制备了纳米CeO2粉. 用红外光谱(IR)、 X射线衍射分析(XRD)和透射电子显微镜(TEM)技术,对制得的纳米CeO2纳米粒子的物相结构、形貌特征、成分等进行了表征. 结果表明,双液超声雾化法能制备出颗粒分散性好,粒度分布均匀的纳米CeO2粒子,所得CeO2粒子为萤石型结构,粒径约为3～5 nm左右. 初步探讨了用超声雾化反应法制备纳米粉的机制,认为CeO2纳米粒子的成核和长大受到液滴大小的限制,是一个液相的微区反应过程,正是液滴的微小体积保证了更小纳米粒子的形成.     

羧甲基葡聚糖磁性纳米微球的制备及表征

采用超声预处理技术,在羧甲基葡聚糖-水分散体系中,通过化学共沉淀法制备羧甲基葡聚糖磁性复合微球．采用IR,TEM,AFM,XRD和振动样品磁强计方法对产物进行了表征．实验结果表明：超声预处理方法能明显提高复合微球的分散性．制得的复合微球呈球形,分散均匀,平均粒径为100nm．它们具有超顺磁性,室温下磁性饱和磁化强度为35emu·g^-1．     

Physical and chemical properties of NiFe<Subscript>2</Subscript>O<Subscript>4</Subscript> nanoparticles prepared by combustion and ultrasonic bath methods

The combustion and ultrasonic bath methods have been utilized to generate nickel spinel ferrite nanoparticles. Physical and chemical properties of generated nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and vibrating sample magnetometer (VSM). Between the nanoparticles generated by mentioned methods, there were differences in size, oxygen-metal bonding, and magnetic properties which have been investigated in the work.     

Ultrasonic Synthesis of Gold Nanoparticles and Its Use in Immunochromatographic Assay for Detection of Kanamycin

An ultrasonic method to synthesize gold nanoparticles with uniform size was reported. Effects of ethanol concentration, solution pH, ultrasonic irradiation power, and time on the formation of gold nanoparticles were investigated. The obtained gold nanoparticles were characterized by ultraviolet-visible (UV-vis) absorption spectra and scanning electron microscope (SEM). The method performed in ethanol solution under ultrasonic irradiation is friendly to the environment. Furthermore, a nanogold-labeled probe was used to develop an immunochromatographic method for detection of kanamycin.     

Preparation and characterization of silver colloids with different morphologies under ultrasonic field

In the ultrasonic field, stable silver colloids were produced by the reduction of AgNO₃ with the protection of PVP using KBH₄ or N₂H₄·H₂O as reductant. The main factors affecting the morphology of silver nanoparticles, such as distribution of the ultrasonic field, ultrasonic time, ultrasonic power, and the species of reductant, were studied. The silver colloids were identified by TEM and spectrophotometry. The results indicate that the factors such as distribution of the ultrasonic field, ultrasonic time, ultrasonic power, and the species of reductant have a great impact on the morphology of the silver nanoparticles. The size of the silver nanoparticles decreases with the ultrasonic power and ultrasonic time increasing. Ag nanoparticles prepared in standing wave field preferentially grow in a certain direction, which is propitious for forming hexagonal-and spherical-like silver nanoparticles. Monodispersed spherical silver nanoparticles are easily synthesized in the diffusion field. The stability of silver colloid becomes improved by ultrasonic treatment. For example, precipitate is not found after several weeks for the silver colloid prepared with an ultrasonic treatment time of 180 min. The silver nanoparticles prepared without ultrasonic treatment are large spherical-like and hexagonal. Well-dispersed spherical silver particles with a mean size of about 20 nm have been prepared under ultrasonic treatment. Spherical, spherical-like, and hexagonal silver nanoparticles can be obtained by changing the reductants. __________ Translated from Journal of Tianjin University, 2006, 39(1) (in Chinese)     

Determination of dextrose in peritoneal dialysis solution by localized surface plasmon resonance technique based on silver nanoparticles formation

Determination of dextrose in peritoneal dialysis with a method based on silver nanoparticles (AgNPs) formation was investigated. In a green chemistry method, silver nanoparticles (AgNPs) were synthesized in the natural polymeric matrix of gelatin. The nanoparticles were characterized with UV–Vis spectroscopy and transmission electron microscopy (TEM). Absorbance signal of AgNPs could be applied to determine the various concentrations of dextrose solutions. Drop wise and ultrasonic methods were used and compared with each other. The dynamic range of methods with limit of detection and relative standard deviations were obtained. Results for real sample (peritoneal dialysis) were satisfied.     

聚合物存在下纳米银复合材料的制备与表征

以聚丙烯腈聚乙二醇嵌段共聚物PAN-b-PEG-b-PAN为稳定剂, 在超声辐照下成功地制备了分散性较好、尺寸均匀的纳米银颗粒. 用X射线衍射(XRD)、红外光谱(FTIR)、透射电镜(TEM)、紫外-可见吸收光谱(UV-Vis)和热分析(TGA)等对制备的纳米银复合材料进行了表征. 红外结果表明超声辐照并没有破坏聚合物的链结构. 聚合物的引入, 对纳米银颗粒起到了很好的分散保护作用. 用低浓度的硝酸银溶液, 得到粒径较小的纳米银颗粒; 随着硝酸银浓度增大, 纳米银颗粒粒径也增大. 而聚合物的浓度增大时, 所得银纳米颗粒粒径减小. 对银纳米颗粒的形成机理进行了讨论.     

Mono and bi-metallic electrocatalysts of Pt and Ag for oxygen reduction reaction synthesized by sonication

Nanoparticles of Ag, Pt and Pt–Ag were synthesized using ultrasonic irradiation with no consecutive thermal treatment to catalyze the oxygen reduction reaction. Metal nanoparticles are supported on carbon substrate. The synthesized materials were characterized by XRD, TEM, and cyclic and lineal voltammetry techniques. The kinetic formation of the metallic nanoparticles in solution was followed using UV–vis spectroscopy. The metal particles have crystalline structure and particle size with < 10 nm in size and in the form of spherical agglomerates. Ag/C exhibits lower electrochemical activity and stability for the ORR compared to Pt/C and Pt–Ag/C in acid medium. The mass and specific activity results demonstrate that the synthesized bimetallic sample exhibits 1.5 and 5 times greater electrochemical activities for the ORR compared to the commercial sample.     

超声辐射法制备与表征DDP修饰锡纳米微粒

金属纳米微粒因自身特殊的光、电、磁和热力学等性能而在催化、光电装置、信息存储以及润滑等领域中有着广阔的应用前景[1~5],因而制备具有特定性能的金属纳米微粒一直是纳米技术领域中的一个研究热点[6~8]。目前制备金属纳米微粒常用的方法主要包括物理法(机械粉碎[9]、气相沉     

Sonochemical intercalation of preformed gold nanoparticles into multilayered clays

Multilayered Na (+)-montmorillonite clays intercalated with Au nanoparticles were synthesized by direct ultrasonic impregnation of preformed gold colloid into the clay matrix. The sonicated composite product then consists of Au nanoparticles homogeneously dispersed in the clay. The resulting clay/nano-Au composite was calcined at 800 degrees C and characterized by BET surface area analysis, transmission electron microscopy, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared measurements. Nearly spherical-shaped gold nanoparticles, with a size of 6 +/- 0.5 nm, are located in the pores of clay calcined at 800 degrees C. Their nanocomposites are thermally stable as was shown by thermogravimetric analysis. No aggregation of the gold nanoparticles was observed during calcination. The proposed ultrasonic intercalation approach is an universal one and can be employed for synthesis of catalytically active metal-clay nanocomposites stable at high temperatures with high dispersability of the metal nanoparticles in the clay matrix.     

聚苯乙烯-丙烯酸纳米粒子的制备及共振光散射性质

聚苯乙烯-丙烯酸纳米粒子的制备及共振光散射性质;无皂乳液聚合;超声辐射