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目的 研究以乙酸锌和氢氧化钠为原料,利用水热合成法制备纳米氧化锌的最佳工艺条件及抗菌性能。方法 以纳米氧化锌的粒径和形貌为评价指标,讨论合成条件对产物的影响;基于单因素设计响应面实验,以抑菌圈直径为响应值,分析抑菌效果较好的纳米氧化锌的制备条件。结果 在水热温度为111.14 ℃,反应时间为10 h,乙酸锌浓度为0.02 mol/L时制备的纳米氧化锌的抗菌效果最好,大肠杆菌的抑菌圈直径为(17.265±0.011)mm。结论 水热温度、水热时间和前驱体浓度会影响纳米氧化锌的粒径和形貌;水热温度和前驱体浓度是影响纳米氧化锌抑菌性的显著因素,水热时间是非显著因素。 相似文献
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应用Monte Carlo方法在10×10×100三维网络中模拟了纳米颗粒在W/O微乳液中的形成过程.研究了反应物浓度、反应物配比、液滴尺寸、界面膜韧性对颗粒形成的影响及与颗粒尺寸和颗粒分布之间的关系,并与前人的实验和研究结果进行了分析比较.模拟结果表明颗粒的形成过程可明显分为成核和成长两个阶段;增加反应物的浓度可以使纳米颗粒尺寸增大;反应物过量使颗粒尺寸减小;膜的韧性越大,形成的颗粒越大,而且分布越均匀;颗粒尺寸随液滴尺寸的增加而增加. 相似文献
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氧化硅包裹四氧化三铁微球的制备及表征 总被引:1,自引:0,他引:1
在室温下,采用H2O2氧化Fe(OH)2悬浮液的方法制备得到了粒径23nm左右的磁性纳米粒子,经X射线衍射检测制备得到的是Fe3O4磁性纳米粒子,粒子的饱和磁化强度为59.05emu/g。先用硅烷偶联剂KH560修饰Fe3O4,提高粒子在乙醇溶液中的单分散性,在此基础上采用溶胶凝胶法通过TEOS水解制备得到分散性佳、尺寸均匀、粒径为25nm左右核壳结构的氧化硅包覆Fe3O4纳米粒子的磁微球。 相似文献
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Soubantika Palchoudhury Fahmeed Hyder T. Kyle Vanderlick 《Particulate Science and Technology》2014,32(3):224-233
We report a simple phase transfer based synthesis route for two novel anisotropic water soluble iron oxide nanoparticle shapes, namely, nanoplates and nanoflowers. The nanoplates and nanoflowers are initially prepared in an organic solvent via a modified “heat-up” method. Then, the crystalline nanoparticles are rendered hydrophilic via sonication in the presence of dextran and water. These nanoparticles are highly monodisperse and superparamagnetic at room temperature. High resolution transmission electron microscopy indicates that the iron oxides cores are not affected by the phase transfer. Dextran coating is confirmed by dynamic light scattering, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The obtained dextran coverage was 26 wt% for the nanoplates and 37 wt% for the nanoflowers. The nanoplates and nanoflowers were not only water soluble, but also remained stable at different pH (4–7) and in common aqueous buffer solutions. Thorough characterizations of the nonspherical iron oxide nanoparticles indicate that these particles could be useful for potential biomedical applications and magnetic resonance imaging. 相似文献
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利用水热法在Si(111)衬底上生长ZnO晶体及稀土掺杂ZnO晶体,并对比考察了它们的电学、光致发光性质.首先采用水热腐蚀法对Si(111)衬底进行预处理,再用水热法在预处理过的Si(111)衬底上制备ZnO晶体或稀土掺杂ZnO晶体,采用XRD、SEM研究了ZnO样品的相结构、表面形貌,结果表明在Si(111)衬底上ZnO样品是棒状的六方柱体,测试了样品的室温光致发光光谱(PL)和伏安特性曲线(I-V曲线),发现ZnO或稀土掺杂ZnO样品分别在466nm、510nm出现较强的发射峰,2个样品都具有类似二极管的整流特性. 相似文献
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In this study, silver nanoparticles were prepared using silver nitrate as the metal precursor, starch as protecting agent, and sodium borohydride (NaBH4) as a reducing agent by the chemical reduction method. The formation of the silver nanoparticles was monitored using ultraviolet-visible absorption spectroscopy, cyclic voltammetry, and particle size analyzer and characterized by transmission electron microscopy (TEM) and x-ray diffraction (XRD). Synthesis of nanoparticles were carried out by varying different parameters, such as reaction temperature, concentration of reducing agent, concentration of silver ion in feed solution, type and concentration of the stabilizing agent, and stirrer speed expressed in terms of particle size and size distribution. Dispersion destabilization of colloidal nanoparticles was detected by Turbiscan. It was observed that size of the starch stabilized silver nanoparticles were lower than 10 nm. The microbial activity of synthesized silver nanoparticles was examined by modified Kirby-Bauer disk diffusion method. Silver nanoparticles were tested for their antibacterial activity against Gram negative bacteria such as Escherichia coli, Pseudomonas aeruginosa, and Gram positive bacteria such as Staphylococcus aureus and Staphylococcus epidermidis. High bacterial activity was observed at very low concentrations of silver (below 1.39 μg/ml). The antifungal activity of silver nanoparticles has been assayed against Candida albicans. 相似文献
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纳米氧化锌材料的制备方法及结构表征 总被引:3,自引:0,他引:3
文章介绍了纳米ZnO材料的常用制备方法,如应用较多的气-固-液法、气相法、水热法和有着较好应用前景的电化学法,以及各类纳米ZnO材料的结构表征,并展望了纳米ZnO材料的发展前景。 相似文献
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纳米碳包铁磁性颗粒的制备及表征 总被引:2,自引:0,他引:2
采用激光感应复合加热蒸发合成法,以CH4为碳源,制备了大量具有壳核结构的纳米碳包铁颗粒,通过透射电子显微镜(TEM)、X射线衍射分析仪(XRD)、能量弥散X射线分析(EDX)等对颗粒进行了表征,并利用动态磁滞回线测定仪测定了纳米颗粒的磁化强度等磁性能.结果表明,利用该方法制备的碳包铁纳米颗粒的平均粒径为25nm,表面碳层厚度为5nm左右,具有铁磁性能.纳米碳包铁颗粒将作为磁性载体在医学细胞分离、细胞染色、靶向用药、定向治疗、肿瘤热疗等方面具有广阔的应用前景. 相似文献
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The size distribution of gold nanoparticles was estimated based on the scattering intensity data obtained from small angle X-ray scattering (SAXS) and compared with the result of micrographs by transmission electron microscopy. The slope of the Guinier plot was used to estimate the mean size assuming a narrow particle size distribution. When the size distribution is narrow, the mean size can be easily obtained from slope of a Guinier plot of scattering data within 10% error. Additionally, assuming a lognormal size distribution, the size distribution and the mean size can be calculated using the experimental SAXS data in the fitting analysis. The histogram method, which utilizes the coefficient matrix of scattering intensity, was also applied to the estimation of the size distribution, and this method could be useful for a rough estimate of the size distribution. 相似文献
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ABSTRACT The size distribution of gold nanoparticles was estimated based on the scattering intensity data obtained from small angle X-ray scattering (SAXS) and compared with the result of micrographs by transmission electron microscopy. The slope of the Guinier plot was used to estimate the mean size assuming a narrow particle size distribution. When the size distribution is narrow, the mean size can be easily obtained from slope of a Guinier plot of scattering data within 10% error. Additionally, assuming a lognormal size distribution, the size distribution and the mean size can be calculated using the experimental SAXS data in the fitting analysis. The histogram method, which utilizes the coefficient matrix of scattering intensity, was also applied to the estimation of the size distribution, and this method could be useful for a rough estimate of the size distribution. 相似文献
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Amino-dextran-functionalized superparamagnetic iron oxide nanoparticles (SPION) were synthesized by two-steps: Dextran-modified SPION was obtained by “one-step” co-precipitation method. Then, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPS) was added to the resultant dextran-SPION to prepare amino-dextran-functionalized SPION (AEAPS/Dex-SPION). The particles were characterized by vibrating sample magnetometer (VSM), transmission electron micrographs (TEM), atomic force micrographs (AFM), gas chromatography and atomic absorption spectrophotometry. The size of the modified particles varied in a range of 30 to 40 nm and did not change significantly after modification. The binding rate of AEAPS was 91.15%. A monoclonal antibody against S100 (anti-S-100), a gold standard for the diagnosis of melanocytic lesions, was conjugated to the AEAPS/Dex-SPION to prepare immuno-SPION. From the result in melanoma B16 cell, the immuno-SPION was proven to have a bio-targeting activity. Such AEAPS/Dex-SPION might be very useful for bio-magnetically targeted detection in early melanocytic lesions. 相似文献
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以化学共沉淀法制备了Fe3O4纳米粒子,壳聚糖经羧甲基化改性后接枝在Fe3O4颗粒表面,得到了磁性羧甲基化壳聚糖(Fe3O4/CMC)纳米粒子.利用透射电镜(TEM)、X射线衍射(XRD)、傅立叶红外光谱(FT-IR)及磁性测试对产物进行了表征.TEM表明Fe3O4纳米粒子被CMC包覆,粒径约10 nm;XRD分析表明复合纳米粒子中磁性物质为Fe3O4;FT-IR表明壳聚糖发生羧甲基反应以及在Fe3O4表面的接枝反应.Fe3O4/CMC纳米粒子具有超顺磁性,比饱和磁化强度25.73 emu/g,有良好的磁稳定性. 相似文献
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为提高铂催化剂的催化活性,降低催化剂成本,在水/TX-4(壬基酚聚氧乙烯醚)/正丁醇/环己烷微乳液体系中成功制备了粒径2~4nm的单分散铂纳米粒子,并对其进行了TEM和EDS表征。微乳液体系的相图表明,Kw=5∶3,m(S-As)/m(O)=3∶2是制备小尺寸铂纳米粒子的最佳配比。H2PtCl6和NaBH4(过量时)浓度增大时,对产物粒径影响不大,但使粒径的均匀性降低;增溶水量ω增大,粒子粒径增大。CH2PtCl6≤25mmol·L-1,CNaBH4≥100mmol·L-1,ω≤2是制备小尺寸、单分散铂纳米粒子的关键,粒子尺寸可通过改变ω值调节。 相似文献
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采用溶胶-凝胶法制备了ZnO量子点, 并采用有机高分子试剂PEG(聚乙二醇, Mw=2000)对其表面进行修饰。借助X射线衍射分析、傅立叶红外光谱、光致发光谱和透射显微镜等测试方法, 研究了PEG表面修饰对ZnO量子点结构和光学性能的影响规律。研究表明, 混合加入的PEG聚合物能够成功地包覆在ZnO量子点表面, 但没有改变量子点的晶体结构, 经PEG表面修饰后的ZnO量子点尺寸变小, 稳定性增强, 分散更均匀。同时经PEG修饰的ZnO量子点在400~500 nm波长区域缺陷态发射峰明显减弱, 表明采用PEG来改善ZnO量子点表面缺陷结构具有良好效果。 相似文献