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101.
Effects of fullerenes and single-wall carbon nanotubes on murine and human macrophages 总被引:2,自引:0,他引:2
The discovery in 1985 of C-fullerenes, a novel carbon allotrope with a polygonal structure made up solely by 60 carbon atoms, and in 1991 of C-nanotubes, thin carbon filaments (1-3 μm in length and 0.001 μm in diameter) with extraordinary mechanical properties, opened a wide field of activity in carbon research. While toxicity and biocompatibility of C-fullerenes have been widely investigated, literature data concerning the biological properties and biotoxicity of C-nanotubes are poor and contradictory. Here we test the ability of highly purified C-Single-Walled-Nanotubes (SWNTs) and C-fullerenes to elicit an inflammatory response by murine and human macrophage cells in vitro. In order to determine the potential of these C-derivatives as biological inducers of inflammatory reactions we evaluate the ability of C-single-walled nanotubes and C-fullerenes to induce the release of NO by murine macrophages cells, to stimulate the phagocytic activity of human macrophage cells and to be cytotoxic against these cells. We show that SWNTs-C-nanotubes, when highly purified, as well as C-fullerenes, do not stimulate the release of NO by murine macrophage cells in culture, their uptake by human macrophage cells is very low, and they possess a very low toxicity against human macrophage cells. 相似文献
102.
Ghurmallah H. Al‐Ghamdi E. David Sudol Victoria L. Dimonie Mohamed S. El‐Aasser 《应用聚合物科学杂志》2006,101(5):3479-3486
Miniemulsion copolymerization of styrene/n‐butyl acrylate was investigated as a means of encapsulating hydrophilic titanium dioxide (TiO2) in a film‐forming polymer. Dispersion studies of the TiO2 were first carried out to determine the choice of stabilizer, its concentration, and the dispersion process conditions for obtaining stable TiO2 particles with minimum particle size. Through screening studies of various functional stabilizers and shelf‐life stability studies at both room and polymerization temperatures, Solsperse 32,000 was selected to give relatively small and stable TiO2 particles at 1 wt % stabilizer and with 20–25 min sonification. The subsequent encapsulation of the dispersed TiO2 particles in styrene/n‐butyl acrylate copolymer (St/BA) via miniemulsion polymerization was carried out and compared with a control study using styrene monomer alone. The lattices resulting from the miniemulsion encapsulation polymerizations were characterized in terms of the encapsulation efficiencies (via density gradient column separations; DGC) and particle size (via dynamic light scattering). Encapsulation efficiencies revealed that complete encapsulation of all of the TiO2 by all of the polymer was not achieved. The maximum encapsulation efficiencies were 79.1% TiO2 inside 61.7% polystyrene and 63.6% TiO2 inside 38.5% St/BA copolymer. As the density of the particles collected from the DGC increased from one layer to another, both the average particle size and the number of the TiO2 particles contained in each latex particle increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3479–3486, 2006 相似文献
103.
超分散稳定纳米ZnS的非水原位构筑及摩擦学性能 总被引:1,自引:0,他引:1
设计并合成了油溶性环烷酸锌和异氰酸酯类超分散稳定剂,采用原位构筑方法获得了非水纳米ZnS分散系,用冷冻蚀刻电镜对其进行了表征,用离心实验对其分散稳定性进行了考察.对纳米粒子的形成过程、分散稳定机理进行了阐述.用环块和四球摩擦试验机对纳米ZnS分散系的摩擦学性能进行了研究.结果表明:ZnS为40 nm的粒状颗粒,大小均匀,在介质中呈单粒子分散;纳米分散系经72 h普通离心和56 h非连续超离心均未发生沉降,表现出理想的分散稳定性;试验显示超分散稳定纳米ZnS的存在,能明显改善油样的抗磨减摩性能和承载能力.在试验范围内,添加的纳米ZnS的量越大,其抗磨减摩性能也越好,但当n-ZnS的质量分数大于0.25%时,其承载能力趋于稳定. 相似文献
104.
采用液相法以硅基上原位合成的金纳米粒子作为催化剂和模板,在不同的反应条件下,用十八烷基硅烷(Octadecylsilane)作为前驱体合成了纳米线状化合物.研究了不同反应条件对该线状化合物形貌的影响,能量散射光谱实验结果表明该线状化合物为聚氧硅烷,扫描电镜结果显示当反应温度控制在110℃和反应时间90min的条件下,可得到均匀的纳米线状化合物.最后提出了聚氧硅烷化合物可能的形成机理,同时也为制备硅基上的硅氧纳米线状化合物提供了一种方便而简单的方法. 相似文献
105.
利用超声化学方法制备的类球形三氧化钼(MoO3)纳米颗粒为前驱物,采用在氧气氛下的硫化还原反应制备纳米二硫化钼(MoS2)粉体。纳米粉体颗粒的形貌、几何特征和尺寸等通过场发射扫描电子显微镜(FE-SEM)和透射电子显微镜(TEM)进行表征,用x-ray射线衍射(XRD)和能谱分析(EDX)分析物质的结构及成分。将制备出的类球形纳米级MoS2作为添加剂,添加到基础油中。通过仪器测试其在不同载荷下的摩擦系数,与基础油的摩擦系数进行对比,研究纳米MoN对复合润滑油润滑性能的影响。结果表明:MoS2纳米颗粒能够显著提高润滑油的润滑性能。 相似文献
106.
制备了柠檬酸钠保护的金和银纳米粒子,并用自组装法制备了金和银纳米粒子修饰的玻碳电极,在近中性的磷酸缓冲溶液中,比较研究对苯二酚在金和银纳米粒子修饰玻碳电极上的电化学响应情况。结果表明金和银纳米粒子均对对苯二酚的电氧化过程具有优越的电催化效果;与银纳米粒子修饰电极相比,金纳米粒子修饰电极表现出了良好的稳定性;对苯二酚在金纳米粒子修饰玻碳电极上的电化学反应是受扩散控制的。 相似文献
107.
采用微波加热法在单晶硅基底上制备纳米镍粒子。考察了镍源、还原剂、表面活性剂、加热方式等实验条件对单晶硅基底上制备纳米镍粒子的影响。对硅基底上纳米镍粒子的成分、结构及表面形态进行了表征。结果表明:以水合肼为还原剂、氯化镍为镍源,微波加热3 min在硅基底上可以制备出直径为30 nm的均匀单一分布的纳米镍粒子。 相似文献
108.
109.
Josianne Lefebvre Federico Galli Claudia L. Bianchi Gregory S. Patience Daria C. Boffito 《加拿大化工杂志》2019,97(10):2588-2593
X‐ray photoelectron spectroscopy (XPS) is a quantitative surface analysis technique used to identify the elemental composition, empirical formula, chemical state, and electronic state of an element. The kinetic energy of the electrons escaping from the material surface irradiated by an x‐ray beam produces a spectrum. XPS identifies chemical species and quantifies their content and the interactions between surface species. It is minimally destructive and is sensitive to a depth between 1–10nm. The elemental sensitivity is in the order of 0.1 atomic %. It requires ultra high vacuum ( Pa) in the analysis chamber and measurement time varies from minutes to hours per sample depending on the analyte. XPS dates back 50 years ago. New spectrometers, detectors, and variable size photon beams, reduce analysis time and increase spatial resolution. An XPS bibliometric map of the 10 000 articles indexed by Web of Science[1] identifies five research clusters: (i) nanoparticles, thin films, and surfaces; (ii) catalysis, oxidation, reduction, stability, and oxides; (iii) nanocomposites, graphene, graphite, and electro‐chemistry; (iv) photocatalysis, water, visible light, and ; and (v) adsorption, aqueous solutions, and waste water. 相似文献
110.
Caroline Cannizzo 《Polymer》2005,46(4):1269-1276
Translucent boronic acid-carrying nanolatexes are prepared by copolymerisation of vinylbenzyl chloride in microemulsion followed by post functionalisation with 3-aminophenylboronic acid. The diol binding capacity and selectivity of the phenylboronic acid remain unchanged after anchoring to polymer nanoparticles (16 nm diameter, 0.22 mmol/g). The binding of a catechol dye, Alizarin Red S (ARS), to the boronic acid-carrying nanoparticles affords a colored, stable, nanolatex which is used for the selective visual detection of fructose in a competitive assay. The binding of fructose at pH 8.2 is readily evidenced by a color change and monitored by UV/Vis spectroscopy. The nanosensor can be regenerated in acidic medium. The entrapment of the nanolatex in a dialysis cell provides a re-usable support for binding and optical detection. 相似文献