The preparation of iron (III) oxide nanoparticles using W/O microemulsion

Iron (III) oxide, Fe₂O₃, nanoparticles were prepared using W/O microemulsion as the reactor. W/O microemulsion was formed using n-heptane as oil phase, water and AOT as the surfactant under the specific composition. Iron (III) Chloride was used as a starting material and Ammonium hydroxide was a precipitating agent. Fe₂O₃, nanoparticles were then produced in situ the water core. Size of particles could be adjusted by the water content of the mixtures. The higher the water content, the bigger the particle size. The average size of the nanoparticles obtained was smaller than 100 nm. Moreover, Fe₂O₃ produced by this method was hematite with hexagonal in structure.     

纳米Pt粒子的微乳液法制备研究

在十六烷基三甲基溴化铵／正辛醇／水（CTAB／C8H17OH／H2O）微乳液中，选择合适的微乳液配比，水合肼为还原剂，常温下制得了粒径为6－8nm的Pt粒子，研究了微乳液的形成条件和水含量对Pt粒子粒径大小的影响，在不同温度下，以He为保护气体，热处理Pt粒了后表明：100摄氏度时，XRD峰中有表面活性剂CTAB存在，200摄氏度时未见杂质成分；温度升高到300摄氏度时，Pt粒子XRD峰变尖变窄，这意味着Pt粒子开始出现晶粒长大，为避免Pt粒子长大，控制一定的热处理温度是必要的。     

微乳液法制备纳米NiO颗粒

以Triton X-100/环己烷/正己醇/水为反相微乳体系,氯化镍和氨水为原料,利用微乳液法成功地制备出了纳米NiO颗粒.并以TG-DTA、XRD,FTIR和TEM对所制备的NiO纳米颗粒进行了表征.结果表明,所制备的氧化镍颗粒为立方结构,粒径约为14nm的球形,颗粒分散均匀,无明显团聚现象.     

Synthesis and conductivity of cerium oxide nanoparticles

Cerium oxide (CeO₂) nanoparticles have been synthesized through composite-hydroxide-mediated approach. The X-ray powder diffraction (XRD) measurement proved that the pure cubic CeO₂ could be obtained at a low temperature region (170-220 °C). The particle size, micrograph morphology and microstructure were investigated by transmission electron microscope (TEM) and environmental scanning electron microscope (ESEM). The conductivity of as-synthesized CeO₂ was measured by a standard four-probe method. The conductivity of CeO₂ increases slightly with the increase of temperature. And the conductivity increases rapidly to 0.02418 s cm^− 1 at 830 °C. The product is a potential material for intermediate temperature solid oxide fuel cells (ITSOFC).     

Fast synthesis of cerium oxide nanoparticles and nanorods

The microwave-hydrothermal method has been investigated for the fast synthesis of rare earth cerium oxide (CeO2) nanoparticles and nanorods. This approach combines the advantages of both hydrothermal and microwave heating techniques. It is facile, rapid, energy-saving, and environmentally-benign and leads to high-yields. The average sizes of the obtained CeO2 nanoparticles could be adjusted from approximatrly 1.6 nm to approximately 20 nm. Moreover, by changing cerium source and adjusting the amount of the added ammonia water, CeO2 nanorods could be synthesized under microwave-assisted conditions for the first time. No calcination process or surfactant is required in our experiments for both CeO2 nanoparticles and nanorods. The ultraviolet and visible (UV-vis) spectra show the obvious size-dependence of the position of the absorbance peak. The Brunaur Emmett Teller (BET) nitrogen adsorption indicates that these nanoparticles and nanorods have high specific surface areas, which are needed for potential applications in many fields. Compared with conventional hydrothermal method, microwave-assisted hydrothermal method shows its advantages of rapidity, convenience and perhaps cost-effectiveness and could be extended to the synthesis of other nanoparticles and nanorods.     

一种制备ZnO纳米颗粒的新方法

提出了一种制备ZnO纳米颗粒的新方法。在金属钠的液氨溶液中还原硝酸锌,所形成的金属Zn自然氧化而制得ZnO颗粒。为了研究表面修饰对产物形貌、粒径和性能的影响,制备了十二烷基磺酸钠（SDS）修饰的ZnO纳米颗粒。采用X射线粉末衍射仪（XRD）、透射电子显微镜（TEM）、傅立叶变换红外光谱仪（FT-IR）、热重及差热分析仪（TG-DTA）等手段对产物进行了表征。结果表明采用该方法可制得具有六方纤锌矿结构的ZnO颗粒,未修饰ZnO颗粒团聚较为严重;修饰的ZnO纳米颗粒呈棒状,分散较好。红外和热分析表明SDS修饰在了ZnO纳米颗粒表面。测试了所制备ZnO颗粒的紫外可见吸收（UV-Vis）和光致发光（PL）谱,均出现了ZnO的特征谱带。提出的方法也适用于制备其它金属或氧化物纳米材料。     

Synthesis of CuS nanocrystal in cationic gemini surfactant W/O microemulsion

In the water-in-oil (W/O) microemulsion stabilized by the cationic gemini surfactant alkanediyl-α, ω (dimethydodecyl-ammonium bromide) (12–3-12, 2Br⁻¹), CuS nanorod, tube-like, and star sheet-like structures are successfully prepared. The effect of the concentration ratio of S²⁻ to Cu²⁺, molar ratio (ω₀) of water to surfactant in solution, incubation time, and absolute reactant concentration on the morphology and size of CuS nanocrystal have been investigated. The properties of the products and their morphologies are characterized by X-ray powder diffraction (XRD), UV–vis absorption spectrum and transmission electron microscopy (TEM). The growth mechanics of the nanocrystal with different morphology is also supposed.     

W/O型微乳液碳化法制备超细Al(OH)3与Al2O3粉体的研究

PEG+正丁醇/正庚烷/水溶液(NaAlO2)体系W/O微乳液中通入CO2,焙烧后制备出了纯度>99.9%、粒度<80nm的Al(OH)3与Al2O3纳米粉体,实验结果表明,乳化温度、表面活性剂与助表面活性剂之比及水相的浓度是决定粉体粒度的主要影响因素.     

Novel mass spectrometric method for phosphorylation quantification using cerium oxide nanoparticles and tandem mass tags

The stoichiometry of protein phosphorylation significantly impacts protein function. The development of quantitative techniques in mass spectrometry has generated the ability to systematically monitor the regulation levels of various proteins. This study reports an integrated methodology using cerium oxide nanoparticles and isobaric tandem mass tag (TMT) labeling to assess absolute stoichiometries of protein phosphorylation. This protocol was designed to directly measure the dephosphorylation levels for a known phosphorylation site, therefore allowing for quantification of phosphosites. Both the accuracy and precision of the method were verified using standard peptides and protein tryptic digests. This novel method was then applied to quantify phosphorylations on eukaryotic initiation factor 3H (eIF3H), a protein integral to overall eukaryotic protein translation initiation. To date, this is the first report of assessment of protein phosphorylation quantification on eIF3.     

TEM observation of gold nanoparticles deposited on cerium oxide

The structure of Au nanoparticles supported on CeO₂ using the deposition precipitation method was observed using a transmission electron microscope (TEM). The shape of Au nanoparticles and the fine structure of contact interface between the Au nanoparticles and CeO₂ supports were carefully examined. It was found that there was a preferential orientation relationship between Au nanoparticles and the CeO₂ support. It was also observed that small and thin Au nanoparticles disappeared during TEM observation, shrinking layer by layer down to a mono-atomic layer.     

W/O/W复乳体系制备聚合物微胶囊的影响因素分析

总结了近年来W/O/W复乳体系制备微胶囊和提高W/O/W型复乳液稳定性的研究进展,重点分析了W/O/W复乳体系制备聚合物微胶囊的影响因素,主要有W/O初乳的稳定性,壁材,外水相,复乳的乳化条件和囊壁固化条件。对微胶囊形貌的改善、包覆率的提高及粒径分布的控制将起到积极作用。     

单分散Fe3O4纳米粒子的合成、表征及其自组装

采用高温有机前驱体分解法,以Fe(acac)3为前驱体制备出单分散性较好的Fe3O4纳米粒子,粒径为(6.4±0.90)nm.利用TEM、XRD、HPPS、FTIR等手段对粒子的形貌及性质进行了研究,证实得到的是Fe3O4单晶,粒子表层的铁原子通过共价键和油酸分子中-COO的两个氧原子结合在一起.通过对自组装过程的初步研究表明随磁性纳米粒子浓度的增加,粒子排布逐渐由零星的无规排列变为规整的单层和多层有序结构.     

Synthesis of worm-like Ag2S nanocrystals in W/O reverse microemulsion

High-aspect-ratio of worm-like Ag₂S nanocrystal with length up to several micrometers and a diameter of 25-50 nm has been successfully prepared by a Triton X-100/cyclohexane/hexanol/water W/O reverse microemulsion in the presence of TAA (Thioacetamide) as a sulfur source and EDTA (ethylene diamine tetraacetic acid) as a chelating ligand. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and UV-vis diffuse reflectance absorption spectra. The results indicate that the morphology and size of Ag₂S nanocrystal can be readily controlled by modulating the mole ratio of Ag⁺ to EDTA, the molar ratio of water to surfactant (ω₀), and the aging time.     

固相反应法制备纳米铈锆复合氧化物

以碳酸铈、碳酸锆、草酸为原料,机械力促进固相反应法制备了纳米级铈锆复合氧化物(CexZr1-XO2)。用TGDSC分析前驱体的热分解温度,通过XRD、TEM、BET等测试手段对产物进行了表征。结果表明:所得产物为单一的立方晶系固溶体,平均粒径<40nm,比表面积达98m2/g。采用中低温固相反应法制备纳米级铈锆复合氧化物无需溶剂,无废液且节能。     

利用SPG膜制备O/W型乳液实验研究

利用孔径为0.6μm的SPG(Shirasu Porous Glass)多孔微滤膜,以异辛烷为分散相、pH=7的磷酸盐缓冲水溶液为连续相、以SDS(十二烷基硫酸钠)和PVA(聚乙烯醇)分别为水相乳化剂和稳定剂,制备了O/W型乳液,研究了操作条件对乳液性能包括液滴大小及分布的影响关系.当跨膜压差在0.12~0.16 MPa时,连续相流速分布在0.20~0.40 m/s时,乳化剂浓度在其临界胶束浓度(CMC)之上时,乳液的单分散性较好.由于乳液具有良好的稳定性和单分散性,可用于多相界面酶催化反应.     

Ultrasonic-assisted preparation of monodisperse iron oxide nanoparticles

Monodisperse iron oxide nanoparticles with 5–20 nm can be synthesized by an inexpensive and simple ultrasonic-assisted method at low temperature. This is based on the decomposition of iron pentacarbonyl in cis–trans decalin. The high energy emitted by ultrasonic irradiation at a short time can promote the crystallization process simultaneously. At low temperature, these crystalline nucleuses can grow to monodisperse nanoparticles. Effects of ultrasonic treatment, the concentration of surfactant and the refluxing time on the size and size distribution of iron oxide nanoparticles were investigated. The morphology and crystal structure of iron oxide nanoparticles obtained at different conditions were characterized by high-resolution transmission electron microscope, X-ray diffraction and selected area electron diffraction.     

Hydrothermal preparation of fractal dendrites: Cerium carbonate hydroxide and cerium oxide

The surfactant-assisted hydrothermal route was used to prepare fractal dendrite cerium carbonate hydroxide (CeOHCO₃) microstructures. After annealing at 600 °C for 4 h, the products were transformed to CeO₂. The crystal structures of the two compounds were determined by X-ray diffraction (XRD). The morphologies and microstructures were characterized by field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). Room temperature photoluminescence (PL) showed that a strong ultraviolet emission at 336 nm was observed for CeOHCO₃, and that centered at 415 nm for CeO₂ microstructures. Both of these emission peaks are different from those reported for CeOHCO₃ and CeO₂ with other shapes. In addition, the possible growth mechanism of dendrite CeOHCO₃ microstructures and the role of surfactant polyvinyl pyrrolidone (PVP) were also investigated in this paper.     

Synthesis of cerium oxide nanoparticles by microwave technique using propylene glycol as a stabilizing agent

Cerium oxide nanoparticles have been synthesized by microwave method using cerium nitrate, propylene glycol and ammonia as a precursors. The material was characterized by XRD, SEM, TEM and UV–visible techniques. XRD analysis revealed all the relevant Bragg’s reflections for face centered cubic crystal structure of cerium oxide. The average particle size was obtained 9 nm from the extrapolation of the Williamson–Hall plot. The value of particle size determined from XRD was in good agreement with the SEM and TEM results. The direct optical band gap was found to be 3.12 eV.