共查询到20条相似文献,搜索用时 890 毫秒
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SDS-PVP水溶液中超细镍粉的制备 总被引:4,自引:0,他引:4
在十二烷基硫酸钠(SDS)-聚乙烯吡咯烷酮(PVP)混合水溶液中, 采用水合肼还原氯化镍制备超细镍粉. SEM结果表明, 该超细镍粉为球形, 表面呈现针状叠合的特殊形貌. XRD结果表明,该超细镍粉由平均粒径约为10 nm的面心立方结构(fcc)的原生纳米镍晶粒组成, 且主要沿(111)晶面生长. TEM清晰观察到原生纳米镍晶粒在PVP的空间桥联作用下自组装成超细镍粉的中间过程. SDS-PVP的组成对超细镍粉的粒径和表面形貌有显著影响, 在一定浓度范围内, 随着SDS或PVP浓度增大, 原生纳米镍晶粒和超细镍粉的平均粒径均呈减小趋势, 表明通过改变SDS-PVP组成可以调控超细镍粉的粒径和形貌. 相似文献
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以Co(NO3)2·6H2O、Na2WO4·2H2O为主要原料,去离子水为溶剂,利用水热法在不同条件下制备了一系列的纳米CoWO4,用XRD、TEM和比表面分析仪对产品的物相、形貌和比表面积进行了表征。较系统地探讨了水热条件(反应混合物pH值、反应时间、反应温度等)对产物物相和形貌的影响,并研究了不同形貌产品对甲醛、乙醇、氨气、苯和丙酮等的敏感性能。结果表明:水热条件对产品的物相和形貌有影响,在不同水热条件下,可成功制备CoWO4纳米颗粒、纳米立方体及纳米棒;以纳米颗粒、纳米立方体及纳米棒样品制成的气敏元件对被试气体有不同程度的响应,其中以纳米颗粒为基的元件在210℃对1 000μL·L-1NH3灵敏度为3.3。 相似文献
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不同形貌氧化锌的微波水热法制备及其光催化性能 总被引:1,自引:1,他引:0
采用微波水热法在乙二醇的辅助下,制备出一系列不同形貌的氧化锌(Zn O)纳米/微米颗粒。扫描电子显微镜测试结果表明,乙二醇的加入量对样品的形貌有着非常显著的影响,通过控制乙二醇的加入量,可以得到不规则片状、六方棱柱孪晶、梭子形和球形等形貌的Zn O纳米/微米颗粒。从微波反应器检测压力结果可以看出,乙二醇的加入量对反应体系的压力影响非常显著,这起到了调控纳米晶生长速度的效果进而得到不同形貌的样品。在此基础上,系统测试了样品在氙灯照射下光催化降解罗丹明B的能力,结果表明,乙二醇加入量大于12 m L时的球状样品光催化效率要远高于其他样品,在50 min内能完成对罗丹明B的降解。 相似文献
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Arthur Zakinyan Yuri Dikansky Marita Bedzhanyan 《Journal of Dispersion Science and Technology》2014,35(1):111-119
The work deals with the experimental study of the emulsion whose dispersion medium is a magnetic fluid while the disperse phase is formed by a glycerin-water mixture. It is demonstrated that under effect of a magnetic field chain aggregates form from the disperse phase drops. Such emulsion microstructure change affects its macroscopic properties. The emulsion dielectric permeability and specific electrical conductivity have been measured. It is demonstrated that under the effect of relatively weak external magnetic fields (~1 kA/m) the emulsion electrical parameters may change several fold. The work theoretically analyzes the discovered regularities of the emulsion electrical properties. 相似文献
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Kathrin E. Peyer Soichiro Tottori Famin Qiu Prof. Dr. Li Zhang Prof. Dr. Bradley J. Nelson 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(1):28-38
Helical microrobots have the potential to be used in a variety of application areas, such as in medical procedures, cell biology, or lab‐on‐a‐chip. They are powered and steered wirelessly using low‐strength rotating magnetic fields. The helical shape of the device allows propulsion through numerous types of materials and fluids, from tissue to different types of bodily fluids. Helical propulsion is suitable for pipe flow conditions or for 3D swimming in open fluidic environments. 相似文献
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Magnetic nano- and microparticles in biotechnology 总被引:1,自引:0,他引:1
Both synthetic and biologically produced magnetic nano- and microparticles exhibit several types of responses to external
magnetic field which have been already employed in various areas of biosciences, biotechnology, medicine, environmental technology,
etc. This short review shows selected important biotechnological applications of magnetic particles, and the biological processes
leading to biogenic magnetic particles formation.
Presented at the 1st Nanomaterials and Nanotechnology Meeting, Nano Ostrava, Ostrava, Czech Republic, 1–4 September 2008. 相似文献
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Mu Niu Meihong Du Zhenyu Gao Chunhui Yang Xianyong Lu Ruirui Qiao Mingyuan Gao 《Macromolecular rapid communications》2010,31(20):1805-1810
Monodispersed polystyrene beads incorporated with Fe3O4 nanoparticles are prepared via dispersion polymerization. The resultant magnetic beads present well‐defined composite structures, excellent colloidal stability, and strong magnetic response. The formation mechanism for the monodispersed composite beads, incorporated with preformed Fe3O4 nanocrystals, was investigated. The potential applications of the monodispersed magnetic beads in bacteria capturing were demonstrated. After being coated with anti‐Salmonella CSA‐1 antibody, the magnetic beads show capturing efficiencies of >99.4% in isolating Salmonella sp.
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Gd5Si1.75Ge1.75Sn0.5的结构、磁相变与磁熵变 总被引:4,自引:0,他引:4
采用粉末XRD和振动样品磁强计研究了Gd5Si1.75Ge1.75Sn0.5合金的结构、磁相变和低场变化下的磁熵变。磁性测量结果表明,Gd5Si1.75Ge1.75Sn0.5合金的磁化强度在居里温度附近发生突变,具有一级相变的典型特征,室温具有Gd5Si2Ge2型单斜结构;合金低场磁热效应非常明显,1.8T磁场变化下,在其居里温度272K附近的最大磁熵变为16.7J.kg-1.K-1。用成本低廉的Sn取代Gd5Si2Ge2中部分Si和Ge后,Gd5Si1.75Ge1.75Sn0.5在低磁场变化下的磁熵变比金属Gd大得多并略高于Gd5Si2Ge2。 相似文献
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双层表面活性剂分散制备水基磁流体 总被引:20,自引:0,他引:20
Fe3O4 magnetic particles were synthesize by chemical co-precipitation. Sodium oleate and poly(ethylene glycol)-4000 were used as bilayer surfactants to envelope the ultra-fine Fe3O4 particles. Then stabilized water base magnetic fluid was obtained. Experiments indicated that surfactants and pH value of the solution had great effect on the stability and size of the magnetic fluid when Fe3O4 particles were synthesized and enveloped. It was the first time to employ this method to prepare magnetic fluid. Using laser diffraction particle size analyzer we found that the average diameter of magnetic fluid was lessen than 84 nanometer. Its magnetization was measured on magnetic balance and the result amounted to 3.84×103A·m-1. Further more, XRD and IR analysis measurements were employed to substantiate the existence of Fe3O4 and surfactant structure. The magnetic fluid can be used as tar-geted-part of nanometer targeted drug delivery system. 相似文献
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Magnetic microspheres were prepared from starch. The microspheres could be crosslinked with various agents, and drugs could
be entrapped adsorbed, or covalently coupled to the microspheres. 相似文献