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采用表面修饰的方法 ,以双十八烷基二硫代磷酸盐 (PyDDP)为表面修饰剂 ,制备了双十八烷氧基二硫代磷酸 (DDP)表面修饰的MnS纳米微粒。采用TEM ,DSC ,XRD和FTIR对表面修饰MnS纳米微粒进行结构分析。结果表明 :表面修饰MnS纳米微粒是由DDP表面修饰层和MnS纳米核心所构成 ,微粒尺寸在 5~ 10nm之间 ,无机MnS纳米晶核具有 γ MnS的晶型结构。DDP表面修饰MnS纳米微粒在氯仿、苯和甲苯等有机溶剂中都具有良好的分散性。 相似文献
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PS/TiO2复合纳米微球的制备和结构表征 总被引:7,自引:0,他引:7
无机纳米微粒具有特殊的物理化学性能 ,近年来在摩擦学领域中受到越来越多的重视 .由于无机纳米微粒难以分散于润滑基础油中 ,故其作为润滑材料主要用作聚合物填料和润滑脂添加剂 .为了改善其在基础油中的分散性 ,需要对无机纳米微粒进行表面改性 ,制备成有机无机复合纳米微粒 ,从而使它们能够用作润滑油添加剂 .目前有机小分子表面修饰无机纳米微粒的摩擦学性能已有报导 [1- 3],但是聚合物修饰无机纳米微粒的研究较少 ,并且大多是采用高分子(如 PVK,PVA等)直接包埋的方法 ,用这种方法制得的微粒 ,粒径差别较大,性能不太稳定 . 本… 相似文献
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以具有生物相容性的三嵌段共聚物聚氧乙烯-聚氧丙烯-聚氧乙烯为表面活性剂,利用多醇合成法制备了Fe3O4纳米微粒;采用X射线粉末衍射仪、傅立叶变换红外光谱仪及透射电子显微镜分析了Fe3O4纳米微粒的晶体结构、化学结构及显微结构,采用振动样品磁强计测定了其磁性能.结果表明,所制得的Fe3O4磁性纳米微粒结晶度高,在室温下显示近似超顺磁性.采用Langevin方程对Fe3O4纳米微粒的磁滞回线进行拟合,结果显示其为磁性单畴.此外,Fe3O4磁性纳米微粒在无机和有机溶剂中均具有很好的分散性,显示出广阔的应用前景. 相似文献
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亲油性ZnS纳米微粒的合成 总被引:20,自引:0,他引:20
纳米微粒具有小尺寸效应、表面效应、量子效应和宏观量子隧道效应等一系列普通材料所不具备的特性 ,因而引起科技工作者的广泛重视 ,成为材料科学研究的热点 .制备纳米微粒的方法很多 [1~ 7] ,但由于纳米微粒的小尺寸效应及表面效应 ,通常制备的无机纳米微粒极易团聚 ,而且无机纳米微粒的非油溶性使其在摩擦学领域的应用受到很大限制 .本文采用表面修饰 [8~ 11] 方法 ,通过共沉淀的竞争反应 ,制备了表面为有机修饰剂双十六烷基二硫代磷酸 (DDP)修饰的无机 Zn S纳米微粒 ,并用红外光谱、 X射线光电子能谱和透射电子显微镜等分析手段对表… 相似文献
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E. Bianchino S. Piotto F. Mavelli M. L. Curri M. Striccoli 《Macromolecular Symposia》2009,286(1):156-163
Dissipative Particle Dynamics has been used to investigate the different morphology of polymer nanocomposites. Such a study was addressed to the definition of a suitable tool for understanding the distribution of oleic acid (OA) capped nanoparticles embedded into poly-methylmethacrylate (PMMA) matrix for the formation of nanocomposite materials. In particular, simulations of PMMA/OA mixtures at different composition have exhibited the self-assembly of amphiphiles to form separated nanosized domains with different morphologies going from spheres, to tubules up to the formation of continuous planar sheets as the OA composition increases. On the other hand, simulations carried out on nanocomposite systems have shown that NPs do not perturb the observed phase behaviour of PMMA/OA mixtures. In fact, at low OA compositions nanoparticles are confined in the spherical lipid domains to form NP clusters, while at high OA composition NPs appear homogeneously distributed in the continuous lipid domain. 相似文献
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Zhang J Wang Y Zheng J Huang F Chen D Lan Y Ren G Lin Z Wang C 《The journal of physical chemistry. B》2007,111(6):1449-1454
In this work, the growth kinetics of thiol-capped PbS nanoparticles was studied. Two-stage growth process was observed, which was controlled first by oriented attachment (OA) mechanism and then by the hybrid Ostwald ripening (OR) and OA mechanism. Different from the NaOH-ZnS system, where OA will occur between any two multilevel nanoparticles, an OA kinetic model only considering the attachment related to original particles was fitted well with the experimental results. Analysis reveals that this model may be a universal one to describe the OA crystal growth process of nanocrystals capped with easily destroyed ligands, such as thiol-ZnS in the previous report. The OA crystal growth characteristics determined by the surface agent were discussed and compared. We propose that with stronger surface capping, the OR growth of nanocrystals is hindered, which facilitates the size controlling via OA kinetics during nanosynthesis. 相似文献
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Octyl octanoate (O-OL) underwent hydrolysis in sodium octanoate (NaOA) reversed micelles in 85:15 = isooctane:octanol (OL) (v/v), containing w = [H2O]/[NaOA] = 40. The products of the hydrolysis, octanoic acid (OA) and octanol (OL), lead to the formation of additional (albeit smaller) reversed micelles; hence the process is considered to be self-reproducing. Self-reproduction was found to be catalyzed by lithium hydroxide, solubilized in the water pools, as well as by hydrogen sulfide, added to the solution of the reversed micelles. Addition of hydrogen sulfide to cadmium perchlorate containing self-reproducing reversed micelles resulted in the formation of cadmium sulfide (CdS) nanoparticles. Diameters of the CdS containing nanoparticles could be altered from 5.4 to 1.8 nm by changing the [Cd2+]/[H2S] ratios from 0.25 to 10. The CdS nanoparticles formed were capped by mercaptopropionic acid, isolated as solids, and could be repeatedly redispersed in water without changing their sizes. Additional CdS nanoparticles were generated in the supernatants removed from the precipitated capped CdS nanoparticles. 相似文献
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TiO_2纳米粒子的表面修饰研究 总被引:1,自引:0,他引:1
利用表面修饰法合成了油酸 (OA)修饰的TiO2 纳米粒子 ,采用红外光谱 (IR)、透射电子显微镜 (TEM)和X射线光电子能谱 (XPS)对表面修饰的TiO2 纳米粒子进行了结构表征 ,并研究了油酸浓度对TiO2 表面覆盖量及在油中分散性能的影响 .研究结果表明通过油酸表面修饰 ,成功合成了具有油分散性能的纳米TiO2 ,并且获得了油酸修饰量与TiO2 的最佳配比 . 相似文献
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M. Sudha S. Senthilkumar R. Hariharan A. Suganthi M. Rajarajan 《Journal of Sol-Gel Science and Technology》2012,61(1):14-22
Nanoparticles of uncapped and PVA (poly vinyl alcohol) capped zinc oxide were synthesized by precipitation method. The synthesized
ZnO nanoparticles were characterized by fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron
microscopy, transmission electron microscopy and thermogravimetric-differential thermal analysis. The photocatalytic activity
of bare and modified ZnO nanoparticles was studied by monitoring the degradation of Rhodamine B. The results show that PVA
capped ZnO nanoparticles has reduced photocatalytic activity than the bare ZnO nanoparticles. The reduction in the chemical
oxygen demand and total organic carbon results also revealed the reduced photocatalytic activity of PVA capped ZnO. The UV-shielding
property was evaluated by measuring the transmittance which shows that both bare and PVA capped ZnO nanoparticles possess
good UV-shielding ability. 相似文献
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TiO_2纳米粒子的表面修饰研究 总被引:22,自引:0,他引:22
利用表面修饰法合成了油酸(OA)修饰的TiO_2纳米粒子,采用红外光谱(IR )、透射电子显微镜(TEM)和X射线光电子能谱(XPS)对表面修饰的TiO_2纳米粒 子进行了结构表征,并研究了油酸浓度对TiO_2表面覆盖量及在油中分散性能的影 响。研究结果表明通过油酸表面修饰,成功合成了具有油分散性能的纳米TiO_2, 并且获得了油酸修饰量与TiO_2的最佳配比。 相似文献
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Pure tin dioxide (SnO2) nanoparticles were synthesized via thermolysis of tin phthalate and tin oxalate in the presence of oleic acid (OA) as solvent. Oleic acid (OA) was employed as an organic solvent, which can be applied to control particle growth and to stabilize the particles. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. The orthorhombic phase SnO2 nanoparticles with average size about 12 nm were synthesized through thermolysis of tin phthalate in the presence of oleic acid. 相似文献
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Garcia B Salome M Lemelle L Bridot JL Gillet P Perriat P Roux S Tillement O 《Chemical communications (Cambridge, England)》2005,(3):369-371
Dihydrolipoic acid (DHLA) capped gold nanoparticles (Au@DHLA) are characterized in solid and liquid states by sulfur K-edge XANES spectroscopy; it clearly shows that DHLA is anchored to gold thanks to both sulfur ends. 相似文献
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Hambrock J Becker R Birkner A Weiss J Fischer RA 《Chemical communications (Cambridge, England)》2002,(1):68-69
Good quality, highly monodispersed capped copper metal nanoparticles have been synthesised in a non-hydrolytic approach using thermal decomposition of the Cu(II) precursor [Cu(OCH(Me)CH2NMe2)2] in a hot coordinating solvent without further reducing agents; the copper nanoparticles have been characterised by optical spectroscopy (UV/VIS), electron microscopy (TEM), electron diffraction (SAED), and dynamic light scattering (DLS). 相似文献
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Li X Xu W Zhang J Jia H Yang B Zhao B Li B Ozaki Y 《Langmuir : the ACS journal of surfaces and colloids》2004,20(4):1298-1304
In this paper, we propose two new approaches for preparing active substrates for surface-enhanced Raman scattering (SERS). In the first approach (method 1), one transfers AgI nanoparticles capped by negatively charged mercaptoacetic acid from a AgI colloid solution onto a quartz slide and then deoxidizes AgI to Ag nanoparticles on the substrate. The second approach (method 2) deoxidizes AgI to Ag nanoparticles in a colloid solution and then transfers the Ag nanoparticles capped by negatively charged mercaptoacetic acid onto a quartz slide. By transfer of the AgI/Ag nanoparticles from the colloid solutions to the solid substrates, the problem of instability of the colloid solutions can largely be overcome. The films thus prepared by both approaches retain the merits of metal colloid solutions while they discharge their shortcomings. Accordingly, the obtained Ag particle films are very suitable as SERS active substrates. SERS active substrates with different coverages can be formed in a layer-by-layer electrostatic assembly by exposing positively charged surfaces to the colloid solutions containing oppositely charged AgI/Ag nanoparticles. The SERS active substrates fabricated by the two novel methods have been characterized by means of atomic force microscopy (AFM) and ultraviolet-visible (UV-vis) spectroscopy. The results of AFM and UV-vis spectroscopy show that the Ag nanoparticles grow with the increase in the number of coverage and that most of them remain isolated even at high coverages. Consequently, the surface optical properties are dominated by the absorption due to the isolated Ag nanoparticles. The relationship between SERS intensity and surface morphology of the new active substrates has been investigated for Rhodamine 6G (R6G) adsorbed on them. It has been found that the SERS enhancement depends on the size and aggregation of the Ag particles on the substrates. Especially, we can obtain a stronger SERS signal from the substrate prepared by method 1, implying that for the metal nanoparticles capped with stabilizer molecules such as mercaptoacetic acid, the in situ deoxidization in the film is of great use in preparing SERS active substrates. Furthermore, we have found that the addition of Cl- into the AgI colloid solution changes the surface morphology of the SERS active substrates and favors stronger SERS enhancement. 相似文献