高压均质法制备枸橼酸喷托维林纳米颗粒

采用高压均质法制备枸橼酸喷托维林纳米颗粒,分析均质压力、均质次数和储存过程对药物颗粒形貌与粒径的影响,通过喷雾干燥制得微粉。结果表明:最优高压均质条件是均质压力为75 MPa、循环5次,制得的纳米颗粒是粒径为100~200 nm的片状结晶,储存稳定;枸橼酸喷托维林纳米颗粒悬浊液喷雾干燥微粉颗粒呈粒径小于1μm的球形,由保持原微观形貌与结构的纳米片状结晶聚集而成。     

直流碳弧法制备碳包覆铁纳米颗粒机理研究

采用直流碳弧等离子体法成功制备了碳包覆铁纳米颗粒,利用透射电子显微镜和高分辨透射电子显微镜、X射线衍射、X射线能谱仪对样品的形貌、物相结构、化学成分和粒度进行表征分析,并对碳包覆纳米金属颗粒的形成机理进行初步探讨。结果表明:直流碳弧等离子体技术制备的碳包覆纳米金属颗粒具有明显的铁核(bcc-Fe)/碳壳(石墨层片)包覆结构,颗粒大多呈球形和椭球形,粒径分布在20~60nm范围,平均粒径为44nm,铁粒子外碳层的厚度为5~8nm。碳包覆铁纳米铁颗粒是通过颗粒内部固态形式的碳自行扩散至颗粒表面和颗粒外部气态形式的碳沉积到颗粒表面形成的。     

NiO包覆Ni纳米颗粒的制备及其氧化特性研究

通过对直流电弧等离子体制备的Ni纳米颗粒钝化处理得到NiO包覆Ni纳米颗粒。并对试样的组成成分、形貌、晶体结构、粒度和氧化特性采用高分辨透射电子显微镜(HRTEM)、X射线衍射(XRD)、透射电子显微镜(TEM)和选区电子衍射(SAED)、热重和差示扫描量热分析仪(TGA/DSC)等手段进行分析。结果表明:经过表面钝化处理的NiO包覆Ni纳米颗粒具有明显的核-壳结构,内核为纳米Ni,外壳为NiO氧化物。颗粒呈球形,粒度均匀,分散性良好,粒径分布在20~70nm范围内,平均粒径为44nm,壳层氧化膜的厚度为5~8nm。壳核结构防止了纳米Ni颗粒的进一步氧化和团聚。     

基于LabVIEW的纳米颗粒动态散射光模拟

采用实验室虚拟仪器工程平台LabVIEW实现了纳米颗粒动态光散射信号的计算机模拟。用G语言(图形语言)设计了信号模拟的框图程序,给出了5nm, 15 nm两种粒径颗粒的模拟动态散射光信号及自相关函数。对模拟信号的粒度分析表明,这两种模拟信号产生的测量偏差分别为0.4nm和-0.6nm。     

纳米颗粒在人类支气管中沉降率的研究

借助欧拉和拉格朗日方法数值模拟了纳米颗粒在人类支气管中的输运和沉降.在采用有限体积法以及k-w湍流模型求解流场的基础上,通过单向耦合的拉格朗日方法得出了水动力、热泳力和布朗力等综合作用下的纳米颗粒的运动轨迹.研究发现,纳米颗粒的沉降率随粒径的增加而降低;非常小的纳米颗粒(≈1 nm)在支气管的沉积非常高,可以达到50%;粒径为5~10 nm的纳米颗粒的沉积是14%~20%;粒径为10~50 nm的纳米颗粒的沉积曲线变化非常小,只有13%左右.上述结果对于支气管中纳米药物和呼吸道疾病治疗设备的研制有很大价值.     

快速热解法制备炭包覆纳米金属磁性颗粒(英文)

以简单金属前躯体为原料通过快速热解法制备炭包覆纳米金属磁性颗粒,通过透射电镜、X-射线衍射、热重-示差扫描同步热分析及振动样品磁强计等对产物形貌、结构、成分与磁性能进行表征。结果表明:采用该方法制备的炭包覆纳米金属磁性颗粒形状为近球形颗粒,粒径均一,其中炭包覆镍纳米磁性颗粒的粒径集中在10nm～30nm范围,炭包覆铁纳米磁性颗粒粒径则在50nm～60nm范围;所制炭包覆纳米金属磁性颗粒在室温下具有顺磁性,其磁性能随金属颗粒含量的变化而改变。该方法有望发展成一种工艺简单,可进行连续工业化生产炭包覆纳米金属磁性颗粒的方法。     

纳米TiO2诱导复合丝素蛋白膜二级结构转变的研究

用溶胶凝胶法制备不同比例纳米TiO2改性再生蚕丝丝素蛋白复合膜.SEM与动态光散射纳米粒度分析仪测试结果表明,该丝素膜中纳米TiO2均匀分散在丝素中,TiO2粒径在100nm以下,同时纳米TiO2在丝素中粒径大小主要决定于凝胶过程,成膜过程对粒径大小影响不大;该丝素膜的二级结构用FTIR、XRD、Raman进行表征.测试结果表明,纯丝素膜中存在SilkⅠ向SilkⅡ两种结晶结构,随着纳米TiO2的生成,可使复合丝素膜的结晶结构从SilkⅠ向SilkⅡ转化,但当纳米TiO2的加入超过一定量时,又破坏复合丝素膜的结晶结构.     

Al2O3纳米流体相变特性的DSC研究

纳米流体相变时所体现出的特性是其作为蓄冷相变材料使用的重要基础。利用差示扫描量热法分别测量了纳米颗粒粒径为10nm、20nm、50nm、100nm、500nm,质量分数为5%、10%、12%、15%、20%,以及降温速率为2℃/min、3℃/min、5℃/min、7℃/min、9℃/min的Al2O3纳米流体的凝固点、冰点、融化点、比热及相变潜热的影响。测量结果表明:纳米流体的凝固点、冰点值都高于去离子水;随着颗粒粒径、质量分数和降温速率的增加,纳米流体的凝固点、冰点逐渐升高,而比热值逐渐减小。融化温度随着颗粒粒径、质量分数的增加而增加,且随着降温速率的增加而小幅度的降低。去离子水的相变潜热值高于纳米流体的潜热值;随着纳米颗粒粒径的增加,潜热值越大;随着质量分数和降温速率的增加,相变潜热值越小。     

ZnO粒径对MC尼龙/纳米ZnO复合材料力学性能的影响

用三种粒径范围的纳米ZnO合成MC尼龙/ZnO复合材料。考察了纳米ZnO的粒径对复合材料力学性能和在复合材料中的分散状况的影响。研究表明,平均粒径为30nm的ZnO合成的MC尼龙/纳米ZnO复合材料中ZnO粒子达到纳米级分散,粒子分布均匀,ZnO对MC尼龙的力学性能提高幅度最大,增强增韧作用非常明显;平均粒径为200nm的纳米ZnO在复合材料中,虽然粒径较大,但分散较均匀,无明显团聚,ZnO对MC尼龙的力学性能也有一定的提高,但提高幅度不大;平均粒径为60nm的ZnO分散难度大,ZnO在复合材料中既有小颗粒的分散,也有大颗粒的团聚体,使材料的力学性能明显不如前两种复合材料。     

离心沉降场流分离技术用于纳米颗粒尺寸的准确表征

以名义粒径为240nm的聚苯乙烯标准纳米颗粒悬浮液为样品,利用离心沉降场流分离仪以0．1％FL-70的水溶液为流动相分离。测定检测器波长为254nm时,纳米颗粒在离心力场的作用下通过分离通道的保留时间,从而确定纳米颗粒的平均粒径,测定值为247nm。此外,还利用扫描电镜法测定了纳米颗粒标准物质的粒径,测定值为220nm,结果表明,离心沉降场流分离技术较扫描电镜法更接近于聚苯乙烯纳米颗粒标准的名义粒径,具有更高的准确度和精密度。该方法可望成为纳米尺度表征的一种参考方法。     

用原子力显微镜研究葡聚糖包覆纳米氧化铁微粒的形貌特征

采用化学共沉淀法合成了葡聚糖包覆的超顺磁纳米氧化铁微粒,用原子力显微镜对其分布状态、微粒形貌和尺度等进行了表征,并与透射电镜观察结果进行了比较。结果表明：葡聚糖包覆的超顺磁纳米氧化铁微粒大小均匀且有规律的定向分布,无团聚现象;透射电镜显示其核心氧化铁纳米粒子的外形主要为不规则的球形,粒径5～20nm被葡聚糖包覆后的纳米氧化铁微粒呈长方体,尺寸为（200-300）nm×（400-600）nm×（50-70）nm。     

Development of an aggregation-based immunoassay for anti-protein A using gold nanoparticles

A unique, sensitive, and highly specific immunoassay system for antibodies using gold nanoparticles has been developed. The assay is based on the aggregation of gold nanoparticles that are coated with protein antigens in the presence of their corresponding antibodies. The aggregation of the gold nanoparticles results in an absorption change at 620 nm that is monitored using an absorption plate reader. To demonstrate the analytical capabilities of the new technique, monodispersed protein A-coated gold particles, averaging 10 nm in diameter, were used to determine the level of anti-protein A in serum samples. The effects of the pH, the temperature, and the concentration of protein A-coated gold nanoparticles on the sensitivity of the assay were investigated using transmission electron microscopy (TEM) and UV/vis absorption spectroscopy. A dynamic range of 2 orders of magnitude and a limit of detection of 1 microg/mL of anti-protein A were observed. The new technique could be used for fast, high-throughput screening of antibodies in clinical diagnostic applications.     

Light emission of gold nanoparticles induced by the reaction of bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide

Light emission at approximately 415 nm was observed for gold particles with diameters of 2.6-6.0 nm dispersed in a solution containing bis(2,4,6-trichlorophenyl) oxalate and hydrogen peroxide. It was found that the light intensity was independent of the protecting reagents of the gold nanoparticles with similar size, the light intensity with gold nanoparticles of 5.0 and 6.0 nm in diameter was stronger than that with gold nanoparticles of 2.6 and 2.8 nm in diameter, and the light intensity increased linearly with the concentration of the gold nanoparticles using 6.0-nm gold nanoparticles. The gold nanoparticles were identified as emitting species, and the quantum yield was determined to be (2.8 +/- 0.3) x 10(-5) using 6.0-nm gold nanoparticles. The light emission is suggested to involve a sequence of steps: the oxidation reaction of bis(2,4,6-trichlorophenyl) oxalate with hydrogen peroxide yielding an energy-rich intermediate 1,2-dioxetanedione, the energy transfer from this intermediate to gold nanoparticles, and the radiative relaxation of the as-formed exited-state gold nanoparticles. The observed luminescence is expected to find applications in the field of bioanalysis owing to the excellent biocompatibility and relatively high stability of gold nanoparticles.     

Anti-amyloidogenic activity of glutathione-covered gold nanoparticles

This study is an investigation of the effect of biocompatible glutathione-covered gold nanoparticles (AuSG_7) with an average size of 3 nm on the amyloid fibrils of hen egg-white lysozyme. The anti-amyloid activity of AuSG_7 nanoparticles on this protein was monitored with thioflavin T assay, atomic force microscopy and transmission electron microscopy. The study found that AuSG_7 nanoparticles in vitro depolymerize the amyloid aggregates and inhibit lysozyme aggregate formation. The ability to inhibit amyloid formation and promote amyloid disassembly has concentration-dependent characteristics: the concentration of nanoparticles at which inhibition is half maximal (IC₅₀) was found to be 6.19 μg/mL, and the concentration at which depolymerization is half maximal (DC₅₀) was found to be 8.26 μg/mL.     

Synthesis and agglomeration of gold nanoparticles in reverse micelles

Reverse micelles prepared in the system water, sodium bis-(2-ethylhexyl) sulfoccinate (AOT), and isooctane were investigated as a templating system for the production of gold nanoparticles from Au(III) and the reducing agent sulfite. A core-shell Mie model was used to describe the optical properties of gold nanoparticles in the reverse micelles. Dynamic light scattering of gold colloids in aqueous media and in reverse micelle solution indicated agglomeration of micelles containing particles. This was verified theoretically with an analysis of the total interaction energy between pairs of particles as a function of particle size. The analysis indicated that particles larger than about 8?nm in diameter should reversibly flocculate. Transmission electron microscopy measurements of gold nanoparticles produced in our reverse micelles showed diameters of 8-10?nm. Evidence of cluster formation was also observed. Time-correlated UV-vis absorption measurements showed a red shift for the peak wavelength. This was interpreted as the result of multiple scattering and plasmon interaction between particles due to agglomeration of micelles with particles larger than 8?nm.     

As2O3纳米粒的制备和体外治疗肺癌及其抗转移机制实验

采用改良的溶胶-凝胶法制备系列的As2O3纳米粒,用透射电镜、扫描电镜、能谱仪、图像分析系统等进行表征及特性检测．应用MTT法研究As2O3纳米粒体外对细胞的增殖抑制作用;用流式细胞仪测定As2O3纳米粒及亚砷酸诱导细胞的凋亡率;用免疫组织化学半定量法检测As2O3纳米粒及亚砷酸处理细胞后Bcl-2、Bax、CD44v6和P53基因的表达改变．研究结果表明,制备的As2O3纳米粒在电镜下呈圆形或椭圆形,分散性较好,平均直径约为80nm、110nm、130nm、150nm和450nm;体外细胞实验证实As2O3纳米粒抗肺癌A-549细胞的效应强于亚砷酸溶液;免疫组织化学半定量法显示As2O3纳米粒有较强的诱导肺癌细胞凋亡的作用,可能与其改变Bcl-2和Bax基因表达（Bcl-2／Bax比值降低）及促进P53基因的表达、抑制CD44v6基因表达有关．     

非水溶胶凝胶法制备ZnO/Al2O3复合纳米颗粒

以无水ZnCl2和无水AlCl3为前躯体,丙酮为溶剂,油酸为氧供体,采用非水溶胶凝胶法制备ZnO/Al2O3复合纳米颗粒,通过X-ray衍射（XRD）、红外光谱（IR）、透射电镜（TEM）和紫外可见分光光度计对制备的颗粒进行表征,结果表明,颗粒为无定形态的ZnO/Al2O3复合纳米颗粒,平均粒径为61nm,呈球形单分散状态,具有良好的油溶性,能均匀稳定地分散在20#机械油中。     

PDDA／Au NPs复合分子沉积膜的制备、表征和摩擦学行为

采用小分子柠檬酸钠对金纳米粒子进行包覆改性,紫外光谱分析经改性的金纳米粒子表面共振吸收峰为526iun,激光纳米粒度仪分析表明其平均粒径为8．4nm．改性后的金纳米粒子通过分子沉积技术,与聚二烯丙基二甲基胺盐酸盐（PDDA）组装,制得单层和多层PDDA／Au NPs复合纳米粒子分子沉积（MD）膜（简称PDDA／Au NPs复合MD膜）．采用原子力显微镜（AFM）研究了PDDA／Au NPs复合MD膜的表面形貌以及摩擦、磨损行为．研究结果表明：该复合膜能降低基底的摩擦力,其中以3层膜降低摩擦力的效果最显著．在氮化硅探针扫描行程达到30次后,膜表面才开始出现磨损痕迹．随着扫描次数的增多,膜表面在探针剪切力的作用下逐渐由致密变得疏松,形成颗粒堆积,使表面粗糙度增大,摩擦力、磨损深度也随之增加．通过实验还发现这种复合膜存在两种非正常磨损现象,即磨损负增长和膜的脱落现象.     

Surface-enhanced vibrational spectroscopy of adsorbates on microemulsion synthesized gold nanoparticles

Very small (<10 nm) monodisperse gold nanoparticles (AuNPs) coated with a monolayer of decanethiol were prepared and their surface-enhanced infrared absorption (SEIRA) spectra were measured in the transmission mode. The AuNPs were prepared by the borohydride reduction of HAuCl(4) inside reverse micelles that were made by adding water to a hexane solution of sodium bis(2-ethylhexyl)sulfosuccinate (AOT). The gold nanoparticles were then stabilized by the addition of decanethiol. Subsequent addition of p-nitrothiophenol both facilitated the removal of excess AOT and showed that the gold surface was completely covered by the decanethiol. SEIRA spectra of decanethiol on gold particles prepared in AOT microemulsions were about twelve times more intense than corresponding layers on gold produced by electroless deposition and gave a significantly less noisy spectrum compared to the corresponding surface-enhanced Raman spectrum. The surface-enhanced Raman scattering (SERS) spectra of the same samples showed that the most intense spectrum was obtained from gold nanoparticles with a mean diameter of 2.5 nm. This result is in contrast to previous statements that SERS spectra could only be obtained from particles larger than 10 nm.     

聚合物包覆纳米Fe的液相法制备与磁性能分析

采用NaBH4液相化学还原工艺在溶剂中以PVP-VAc嵌段共聚物形成的微反应器中制备表面包覆有嵌段共聚物的金属铁纳米颗粒,通过XRD、TEM、紫外和红外光谱对其结构和形貌进行分析,用振动样品磁强计分析其磁性能,XRD表明所制备的纳米铁粉为体型立方晶;TEM显示样品为球形,且分散良好,颗粒尺寸在12-35nm之间;紫外和红外光谱分析表明,纳米铁颗粒表面包覆了PVP-VAc嵌段共聚物;磁滞回线显示,纳米铁粉的矫顽力为190Oe,饱和磁化强度为18.6emu.g-1。