亲油性硫化锰纳米微粒的化学制备和结构

采用表面修饰的方法,在醇水体系中制备了双十八烷基二硫代磷酸（DDP）表面修饰的硫化锰（MnS）纳米微粒,用XPS、FTIR、TGA、TEM和HREM等技术对用表面修饰法得到的MnS纳米微粒的结构、化学稳定性和热稳定性进行研究,结果表明：表面修饰得到的MnS纳米微粒有较好的化学稳定性和热稳定性,并且微粒的分散件好、不团聚,制备出的MnS纳米晶核具有γ－MnS的晶型结构。     

II-VI族半导体荧光纳米微粒及复合荧光微球的制备及应用

本文简单介绍了半导体荧光纳米微粒（又称量子点）的基本概念和荧光性质，评述了II－VI族半导体荧光纳米微粒（NCs）的制备和性质研究进展，尤其对基于荧光纳米微粒的复合荧光微球的制备、性质及改进方法进行了详细的讨论，指出目前存在问题和发展方向。     

氧化锌纳米微晶的顺磁共振特性

半导体纳米微粒是制备新一代电子器件的理想材料［1，2］．电子自旋共振谱（ESR）是研究纳米微晶表面电子自旋构象和表面结构的一种有效方法．体相ZnO是一种抗磁性物质，通常观察不到顺磁共振信号（ESR）．有关ZnO纳米微晶电子顺磁共振特性研究还未见文献报导．本文ZnO纳米微晶是用微乳法制备的：这样就制成了纳米尺度的具有表面包覆的ZnO微粒有机溶胶．这里表面活性剂起着“空间位阻”作用，一方面防止成胶过程中粒子间的聚合，使胶粒均匀细小；另一方面，包覆能减少微粒表面缺陷，使粒子性质变得十分稳定．将上述制得的ZnO纳米微粒…     

一种新的制备纳米微粒的方法-快速均匀沉淀法

纳米微粒是指颗粒尺寸为纳米量级（１～１００ｕｍ）的超细微粒,当粒子尺寸进入纳米量级时,其本身具有量子尺寸效应小尺寸效应、表面效应和宏观量子隧道效应,因而在催化、非线性光学、磁性材料、医药及新材料等方面有广阔的应用前景［１］．九十年代以来,纳米微粒和纳米材料的研究已引起世界各国的高度重视,其制备方法概括起来分为三大类：固相法、液相法和气相法。其中液相法由于制备形式的多样性,操作简便,粒度可控等特点而备受人们重视。近年来,液相法制备纳米颗粒的新方法不断涌现［２,３］,推动着纳米材料科学的不断发展。本…     

纳米微粒的微乳液制备法

Ｗ／Ｏ微乳液制备纳米微粒是一新兴的研究领域。本文系统地介绍了乳浮液制备法的基本原理、微乳液“水池”中纳米微粒的鉴定方法、目前该领域的研究进展，并提出了适用于制备纳米微粒的微乳液体系的选择标准及该领域研究工作的展望。     

有序介孔碳CMK-3负载金纳米微粒复合材料的制备和表征

分别采用等体积浸渍-甲醛还原、等体积浸渍-氢气还原及溶胶负载法在介孔碳CMK-3上负载金纳米微粒;利用透射电镜和粉末X射线衍射仪对比分析了采用3种方法得到的复合材料的微结构和相组成;并测定了采用溶胶负载法得到的不同金含量的复合材料的热稳定性.结果表明,所制备的金纳米微粒的尺寸因制备方法不同而呈现明显差异;负载于复合材料中的金纳米微粒具有很好的热稳定性.     

含羧/酯基有机分子对氧化铝微粒形态调控作用研究

研究了液相法制备纳米微粒过程中，某些含羧／酯基有机分子（乙酸， 乙酰乙酸乙酯，聚酰胺羧酸盐等）分别在水相和有机相中对氧化铝纳米微粒形态的调控作用，通过选择该类有机物的种类和用量，制备了不同粒径范围的球形和不同长径比的纤维状Al2O3纳米粒子，并结合有关理论讨论了官能氧在不同合成介质中对颗粒形态调控的可能机理。     

La2（C2O4）3纳米微粒的摩擦学行为研究

纳米摩擦学是９０年代摩擦学研究最活跃的领域之一［１］。稀土元素由于具有４ｆ电子特性,使其元素及其化合物具有许多特殊的性能［２～８］。本研究采用吸附共沉淀表面修饰法制备了烷基磷酸盐修饰的Ｌａ２（Ｃ２Ｏ４）３纳米微粒,并将其分散于润滑基础油中考察其摩擦学行为。利用有机脂肪链的减摩、纳米微粒的抗磨以及稀土元素的特殊作用,提高润滑油的摩擦学性能,拓宽稀土化合物在润滑材料领域的应用。１　实验部分１１　表面修饰Ｌａ２（Ｃ２Ｏ４）３纳米微粒的制备在醇水混合溶剂中,加入一定量的烷基磷酸吡啶盐（自制）和草酸盐…     

液相分散法制备硬脂酸修饰铋纳米微粒

金属纳米微粒由于具有不同于普通材料的光、电、磁、热力学和化学反应等性能,在催化、信息存储、光电、微电子以及润滑等领域中有着广阔的应用前景。金属纳米微粒这些特殊的物理化学性能主要取决于制备工艺和具体的反应条件,因此研究具有特定性能的金属纳米微粒一直是纳米技术领域中的一个研究热点犤1,2犦,目前制备金属纳米微粒最常用的方法是液相法,它是通过在含有表面修饰剂的溶剂中还原相应的金属盐犤3,4犦或有机金属化合物热分解犤5,6犦来制备表面修饰的金属纳米微粒。虽然这种方法能够制备出多种具有特定性能的金属纳米微粒,但是这种方…     

水热微乳液法合成BaLiF3：Er^3＋纳米微粒及表征

采用水/CTAB/正丁醇/正辛烷体系微乳液法及水热技术制备了BaLiF3∶Er^3＋纳米微粒。利用X射线衍射（XRD）、环境扫描电镜（ESEM）和红外荧光光谱等手段对所制备产物进行了表征。X射线衍射数据表明,所制备微粒与JCPDS标准卡片18-715吻合很好,利用谢乐公式计算所制备产物平均粒径在98.45 nm左右,与环境扫描电镜观察结果基本相同。BaLiF3∶Er^3＋纳米微粒的红外发射图谱由4个峰构成,最强峰位于1540 nm处,属于Er^3＋的f→f跃迁。     

Electrophoretic deposition of nickel, iron and aluminum nanoparticles on carbon fibers

The electrophoretic deposition (EPD) of nickel (Ni), iron (Fe) and aluminum (Al) nanoparticles fabricated by an active hydrogen plasma evaporation method on the surface of carbon fibers was investigated, which will allow the obtained composites to be applied as practical catalysts or electrodes. SEM observations show that the Ni nanoparticles can build up a thick EPD coating with some cracks on the surface of carbon fibers, and the analyses of X-ray diffraction (XRD) and BET specific surface area indicate that fine particles from the as-received Ni powders were finally deposited after the EPD process without crystal growth. The surface oxidation of Fe and Al nanoparticles takes serious effect on the EPD process and the morphology of the as-prepared coatings.     

Small angle X-ray scattering analysis of the effect of cold compaction of Al/MoO3 thermite composites

Nanothermites composed of aluminum and molybdenum trioxide (MoO(3)) have a high energy density and are attractive energetic materials. To enhance the surface contact between the spherical Al nanoparticles and the sheet-like MoO(3) particles, the mixture can be cold-pressed into a pelleted composite. However, it was found that the burn rate of the pellets decreased as the density of the pellets increased, contrary to expectation. Ultra-small angle X-ray scattering (USAXS) data and scanning electron microscopy (SEM) were used to elucidate the internal structure of the Al nanoparticles, and nanoparticle aggregate in the composite. Results from both SEM imaging and USAXS analysis indicate that as the density of the pellet increased, a fraction of the Al nanoparticles are compressed into sintered aggregates. The sintered Al nanoparticles lost contrast after forming the larger aggregates and no longer scattered X-rays as individual particles. The sintered aggregates hinder the burn rate, since the Al nanoparticles that make them up can no longer diffuse freely as individual particles during combustion. Results suggest a qualitative relationship for the probability that nanoparticles will sinter, based on the particle sizes and the initial structure of their respective agglomerates, as characterized by the mass fractal dimension.     

纳米Al2O3颗粒对纯Fe液诱导凝固过程的分子动力学模拟

采用分子动力学(MD)方法模拟了不同半径大小的纳米Al2O3颗粒夹杂在三个温度下(1750、1730和1710K)对纯Fe液的诱导凝固过程,并分析了作为诱导核心的纳米Al2O3颗粒的结构演变及其对Fe原子体系的凝固过程的影响.发现在诱导过程中,纳米Al2O3颗粒的内部保持较好的晶型结构,仅表面原子有结构变形;诱导凝固的Fe原子主要为面心立方(fcc)和密排六方(hcp)原子;纳米Al2O3颗粒的尺寸越大,发生诱导凝固的温度越高;诱导凝固得到的Fe晶体的晶格取向受纳米Al2O3颗粒在Fe液中的漂移程度影响.     

Titania-silver and alumina-silver composite nanoparticles: novel, versatile synthesis, reaction mechanism and potential antimicrobial application

Titania-silver (TiO(2)-Ag) and alumina-silver (Al(2)O(3)-Ag) composite nanoparticles were synthesised by a simple, reproducible, wet chemical method under ambient conditions. The surface of the oxides was modified with oleic acid, which acted as an intermediate between the oxide surface and the silver nanoparticles. The resulting composite nanoparticles were thoroughly characterised by XRD, TEM, XPS, FTIR and TGA to elucidate the mode of assembly of Ag nanoparticles on the oxide surfaces. Epoxy nanocomposites were formulated with TiO(2)-Ag and Al(2)O(3)-Ag to examine potential applications for the composite nanoparticles. Preliminary results from disc diffusion assays against Escherichia coli DH5α and Staphylococcus epidermidis NCIMB 12721 suggest that these TiO(2)-Ag and Al(2)O(3)-Ag composite nanoparticles have potential as antimicrobial materials.     

Tailoring the carbon nanostructures grown on the surface of Ni-Al bimetallic nanoparticles in the gas phase

A gas-phase, one-step method for producing various aerosol carbon nanostructures is described. The carbon nanostructures can be selectively tailored with either straight, coiled, or sea urchin-like structures by controlling the size of Ni-Al bimetallic nanoparticles and the reaction temperature. The carbon nanostructures were grown using both conventional spray pyrolysis and thermal chemical vapor deposition. Bimetallic nanoparticles with catalytic Ni (guest) and non-catalytic Al (host) matrix were reacted with acetylene and hydrogen gases. At the processing temperature range of 650-800 °C, high concentration straight carbon nanotubes (S-CNTs) with a small amount of coiled carbon nanotubes (C-CNTs) can be grown on the surface of seeded bimetallic nanoparticle size <100 nm, resulting from consumption of the melting Al matrix sites; sea urchin-like carbon nanotubes (SU-CNTs) of small diameter (～10±4 nm) can be grown on the bimetallic nanoparticle size >100 nm, resulting from the significant size reduction of the available Ni sites due to thermal expansion of molten Al matrix sites without consumption of Al matrix. However, at the processing temperature range of 500-650 °C, C-CNTs can be grown on the bimetallic nanoparticle size <100 nm due to the presence of Al matrix in the bimetallic nanoparticles; SU-CNTs of large diameter (～60±13 nm) can also be grown on the bimetallic nanoparticle size >100 nm due to the isolation of Ni sites in the Al matrix.     

Au nanoparticles prepared by physical method on Si and sapphire substrates for biosensor applications

Gold nanoparticles heavily functionalized with oligonucleotides have been used in a variety of DNA detection methods. The optical properties of three-dimensional aggregates of Au nanoparticles in solution or deposited onto suitable surfaces have been analyzed to detect hybridization processes of specific DNA sequences as possible alternatives to fluorescent labeling methods. This paper reports on the preparation of gold nanoparticles directly deposited onto the surface of silicon (Si) and sapphire (Al2O3) substrates by a physical methodology, consisting in the thermal evaporation of a thin Au film and its successive annealing. The method guarantees the preparation of monodispersed single-crystal Au nanoparticles with a strong surface plasmon resonance (SPR) peak centered at about 540 nm. We show that the changes of SPR excitation before and after DNA functionalization and subsequent hybridization of Au nanoparticles immobilized onto Si and Al2O3 substrates can be exploited to fabricate specific biosensors devices in solid phase.     

In situ preparation of Al-containing PVDF ultrafiltration membrane via sol-gel process

Recently, inorganic nanoparticles blended within polymeric membranes have shown improved antifouling performance in wastewater treatment. However, agglomeration of nanoparticles remains as one of the major obstacles for generating a uniform surface. In this study, a new method for in situ preparation of Al-containing PVDF ultrafiltration membranes to improve the dispersion of nanoparticles is reported. The strategy of this method is to combine sol-gel process with traditional immersion precipitation process. Al sol was synthesized by the addition of anionic exchange resin in N,N-dimethylformamide (DMF) solvent containing aluminum chloride. Homogeneous Al-containing PVDF casting solution was then obtained by dissolving PVDF polymer in the Al sol. The membrane formation mechanism was investigated by precipitation kinetics and morphology. Results indicate that the addition of Al species can accelerate phase inversion of casting solution. Scanning electron microscopic images show that a typical transition from sponge-like structure to finger-like structure occurred with increasing Al species content. The existence and dispersion states of Al species in the resultant membrane matrix were further examined by transmission electron microscope and X-ray photoelectron spectrometer. The results indicate the Al species nanoparticles were well dispersed throughout PVDF matrix. Dynamic BSA fouling resistance experiments demonstrate the Al-containing PVDF membranes possess improved separation performances over the pure PVDF membranes.     

Structural investigation of aluminium doped ZnO nanoparticles by solid-state NMR spectroscopy

The electrical conductivity of aluminium doped zinc oxide (AZO, ZnO:Al) materials depends on doping induced defects and grain structure. This study aims at relating macroscopic electrical conductivity of AZO nanoparticles with their atomic structure, which is non-trivial because the derived materials are heavily disordered and heterogeneous in nature. For this purpose we synthesized AZO nanoparticles with different doping levels and narrow size distribution by a microwave assisted polyol method followed by drying and a reductive treatment with forming gas. From these particles electrically conductive, optically transparent films were obtained by spin-coating. Characterization involved energy-dispersive X-ray analysis, wet chemical analysis, X-ray diffraction, electron microscopy and dynamic light scattering, which provided a basis for a detailed structural solid-state NMR study. A multinuclear ((27)Al, (13)C, (1)H) spectroscopic investigation required a number of 1D MAS NMR and 2D MAS NMR techniques (T(1)-measurements, (27)Al-MQMAS, (27)Al-(1)H 2D-PRESTO-III heteronuclear correlation spectroscopy), which were corroborated by quantum chemical calculations with an embedded cluster method (EEIM) at the DFT level. From the combined data we conclude that only a small part of the provided Al is incorporated into the ZnO structure by substitution of Zn. The related (27)Al NMR signal undergoes a Knight shift when the material is subjected to a reductive treatment with forming gas. At higher (formal) doping levels Al forms insulating (Al, H and C containing) side-phases, which cover the surface of the ZnO:Al particles and increase the sheet resistivity of spin-coated material. Moreover, calculated (27)Al quadrupole coupling constants serve as a spectroscopic fingerprint by which previously suggested point-defects can be identified and in their great majority be ruled out.     

Impact of Al nanoparticles upon the microstructure and wear properties of Ni-Cr-Al nanocomposite coatings

Ni–7Cr and Ni–7Cr–2Al (wt.%) nanocomposite coatings were fabricated by co-electrodeposition of Ni with Cr (40 nm) or and Al (75 nm) nanoparticles from a nickel sulfate bath, their microstructure, friction and wear performance were comparably evaluated in order to elucidate the effect of Al nanoparticles on the properties of nanocomposite coatings. The results indicated that the co-deposition of minor Al nanoparticles significantly increases the microhardness and wear resistance because Al nanoparticles with surface amorphous oxides layers exert the dispersion-strengthening effect like Al₂O₃ nanoparticles.     

Cation distribution in co-doped ZnAl2O4 nanoparticles studied by X-ray photoelectron spectroscopy and 27Al solid-state NMR spectroscopy

Co(x)Zn(1-x)Al(2)O(4) (x = 0.01-0.6) nanoparticles were synthesized by the citrate sol-gel method and were characterized by X-ray powder diffraction and transmission electron microscopy to identify the crystalline phase and determine the particle size. X-ray photoelectron spectroscopy and (27)Al solid-state NMR spectroscopy were used to study the distribution of the cations in the tetrahedral and octahedral sites in Co(x)Zn(1-x)Al(2)O(4) nanoparticles as a function of particle size and composition. The results show that all of the as-synthesized samples exhibit spinel-type single phase; the crystallite size of the samples is about 20-50 nm and increases with increasing annealing temperature and decreases with Co-enrichment. Zn(2+) ions are located in large proportions in the tetrahedral sites and in small proportions in the octahedral sites in Co(x)Zn(1-x)Al(2)O(4) nanoparticles. The fraction of octahedral Zn(2+) increases with increasing Co concentration and decreases with increasing particle size. Besides the tetrahedral and octahedral coordinations, the presence of the second octahedrally coordinated Al(3+) ions is observed in the nanoparticles. The change of the inversion parameter (2 times the fraction of Al(3+) ions in tetrahedral sites) with Co concentration and particle size is consistent with that of the Zn fraction in octahedral sites. Analysis of the absorption properties indicates that Co(2+) ions are located in the tetrahedral sites as well as in the octahedral sites in the nanoparticles. The inversion degree of Co(2+) decreases with increasing particle size.