一种在固体基底上制备高度取向氧化锌纳米棒的新方法

采用廉价、低温的方法，在修饰过ZnO纳米粒子膜的ITO基底上成功制备出具有 高长径比、高度取向的ZnO纳米棒阵列，用扫描电子显微镜(SEM)，X射线衍射(XRD) ，高分辨透射电子显微镜(HRTEM)以及拉曼光谱对制备出的ZnO纳米棒的结构和形貌 进行了表征，测试结果表明，ZnO纳米棒是单晶，属于六方晶系，与基底直，上仍 沿(001)晶面择优生长的特征，并且ZnO纳米棒基本上无氧空位的存在，统计结果显 示，水热反应2h后90%以上的ZnO纳米棒直径为120～190nm，长度为4μm     

Micelle-assisted synthesis of polyaniline/magnetite nanorods by in situ self-assembly process

Polyaniline/magnetite nanocomposites consisting of polyaniline (PANI) nanorods surrounded by magnetite nanoparticles were prepared via an in situ self-assembly process in the presence of PANI nanorods. The synthesis is based on the well-known chemical oxidative polymerization of aniline in an acidic environment, with ammonium persulfate (APS) as the oxidant. An organic acid (dodecylbenzenesulfonic acid, DBSA) was used to replace the conventional strong acidic (1 M HCl) environment. Here, dodecylbenzenesulfonic acid is used not only as dopant, but also as surfactant in our reaction system. So, DBSA can excellently control the morphology and size of PANI nanorods and magnetite particles. Magnetite particles were formed simultaneously during sedimentation, and the formed nanorods were also decorated by the particles. The resulting PANI/magnetite composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). It is found that PANI/magnetite nanorod composites have uniform size, superparamagnetism and a small mass fraction of magnetite, thermal stabilization even at a higher temperature.     

模板合成H_4PMo_(11)VO_(40)/聚苯胺纳米线列阵及其聚合机理探讨

在氧化铝模板中制备了HPA/PANI纳米线列阵,SEM、TEM表明列阵中纳米线直径约为80 nm;XRD与FT-IR证明形成了有效掺杂;单根纳米线的导电率为16.2 S.cm-1;材料的TG-DTA表明PANI纳米线材料有三步失重过程,失去吸附水过程,多酸失去结晶水和PANI结构持续分解过程,多酸结构分解过程;在氧化聚合过程中H4PMo11VO40即为质子酸又为氧化剂和掺杂剂;聚合反应采用自由基机理进行,掺杂反应发生在形成醌二亚胺式自由基正离子和双苯胺式自由基正离子和醌二亚胺式自由基正离子偶联聚合成链结构时.     

Influence of different substrates on ZnO nanorod arrays properties

Zinc Oxide (ZnO) nanorod arrays were grown on different substrates by hydrothermal method. The crystallinity of ZnO nanorod was regularly investigated by X-ray diffraction (XRD). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine morphology of the ZnO nanorods. The results indicate that the nanorods grow along [002] orientation. SEM and TEM images and XRD patterns show that the growth of ZnO nanorods on graphene/Quartz substrate is better than the other substrates due to the number and size of the nanorods which are highly affected through the properties of ZnO seed layers and it has lower defects than the other substrates. PL spectra ZnO would have a higher concentration of oxygen vacancy.     

Synthesis of one-dimensional silver oxide nanoparticle arrays and silver nanorods templated by Langmuir monolayers

One-dimensional (1D) silver oxide nanoparticle arrays were synthesized by illuminating the composite Langmuir-Blodgett monolayers of porphyrin derivatives/Ag(+) and n-hexadecyl dihydrogen phosphate (n-HDP)/Ag(+) deposited on carbon-coated copper grids with daylight and then exposing them to air. Transmission electron microscopy (TEM) observation shows that the nanoparticle size is around 3 nm, with the separation of about 2-3 nm. High-resolution TEM (HRTEM) investigation indicates that the particles are made up of Ag(2)O. Ag nanorods with the width of 15-35 nm and the length of several hundreds of nanometers were synthesized by irradiating the composite Langmuir monolayers of porphyrin derivatives/Ag(+) and n-HDP/Ag(+) by UV-light directly at the air/water interface at room temperature. HRTEM image and selected-area electron diffraction (SAED) pattern indicate that the nanorods are single crystals with the (110) face of the face-centered cubic (fcc) silver parallel to the air/water interface. The formation of the 1D arrays and the nanorods should be attributed to the templating effect of the linear supramolecules formed by porphyrin derivative or n-HDP molecules in Langmuir monolayers through non-covalent interactions.     

Structural and vibrational characterization of polyaniline nanofibers prepared from interfacial polymerization

This work deals with the structural and vibrational characterization of PANI nanofibers prepared through interfacial polymerization using different concentrations of HCl aqueous solution. The results were compared to those obtained by PANI prepared through the conventional route. X-ray diffraction and small-angle X-ray scattering techniques showed that high concentrations of HCl solutions used in the preparation of the PANI nanofibers reduce their crystallinity. The increase of regions with granular morphology was also observed in the scanning electron microscopy images. The changes in the resonance Raman spectra from 200 to 500 cm (-1), FTIR spectra, and the EPR data of the PANI nanofibers reveal an increase in the torsion angles of C ring-N-C ring segments owing the formation of bipolarons in the PANI backbone higher than the PANI samples prepared by conventional route.     

Highly luminescent zinc(II)-bis(8-hydroxyquinoline) complex nanorods: sonochemical synthesis, characterizations, and protein sensing

Highly luminescent zinc(II)-bis(8-hydroxyquinoline) (Znq(2)) complex nanorods have been synthesized via a sonochemical route from the microemulsion containing zinc acetate and 8-hydroxyquinoline. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that the products were rod-like morphology with a diameter of about 200-450 nm and a length of about 1-3 microm. A possible mechanism for the formation of Znq(2) nanorods is proposed that the ultrasound wave might urge the collision and fusion of initial Znq(2) nuclei to form nanorods. The photoluminescence (PL) and resonance light scattering (RLS) of the products were also investigated. The Znq(2) nanorods were found to be sensitive to several proteins, such as human serum albumin (HSA), bovine serum albumin (BSA), bovine hemoglobin (Hb), and egg albumin (EA), displaying an increase in intensities of both PL and RLS. The protein-concentration dependence of the PL and RLS intensities can be well described as a Langmuir-type binding isotherm. This is the first report on the enhancement of PL and RLS intensities of Znq(2) nanorods by proteins. On the basis of enhanced PL and RLS intensities, the protein could be detected at the nanogram per milliliter level. The experimental results clearly showed that the Znq(2) nanorods were good protein probes for easy and highly sensitive detection.     

模板法制备高度有序的聚苯胺纳米纤维阵列

近年来,利用化学或物理方法制备多种材料的纳米有序阵列复合结构已成为学术界的研究热点．用具有纳米孔洞的模板(多孔阳极氧化铝、多孔硅以及聚碳酸脂膜)制备的金属、半导体、碳纳米管等材料的纳米有序阵列复合结构已在润滑、微电极、单电子器件、传感器、垂直磁记录、场致电     

Coherent Anti‐Stokes Emission from Gold Nanorods and its Potential for Imaging Applications

We used coherent anti‐Stokes scattering (CAS) to characterize individual gold nanorods (GNRs) and GNR aggregates. By creating samples with different densities of GNRs on silicon wafer substrates, we were able to determine surface coverage by scanning electron microscopy (SEM) and then correlate the coverage to the CAS intensities of the samples. The observed CAS signal intensity was quadratically dependent on the number of particles. We also examined the CAS signal as a function of the excitation polarization and found that the strongest signals in regularly oriented GNRs were observed when the beam polarization was aligned with the longitudinal axis of the GNRs. Irregularly oriented GNRs exhibited a different scattering pattern to that observed for regularly oriented GNRs. The polarization‐dependent scattering from oriented GNRs showed cos⁶ (θ) behavior. By imaging nanoscale‐sized GNR patterns using CAS and evaluating the results with SEM, we show that CAS can be used for efficient, label‐free imaging of nanoscale metallic particles.     

Fabrication and self-assembly of hydrophobic gold nanorods

Hydrophobic gold nanorods were fabricated from hydrophilic gold nanorods coated with hexadecyltrimethylammonium bromide by treating with mercaptopropyltrimethoxysilane (MPS) and subsequently octadecyltrimethoxysilane (ODS). The fabrication of the hydrophobic shell went through the process of (1) binding MPS onto the nanorods, (2) hydrolysis of methoxysilanes, and (3) immobilization of ODS by dehydration condensation. The 2- or 3-D ordered structures of hydrophobic nanorods were self-assembled by the evaporation of solvent on a substrate. The aspects of 2-D assemblies were dependent on the concentration of the nanorods, as was seen in transmission electron microscopic images. At a low concentration, the nanorods assembled parallel to the substrate, whereas they stood on the substrate at a high concentration. On the other hand, in a solid of the gold nanorods, the formation of the 3-D assembly was confirmed by small-angle X-ray scattering. The assembly consisted of hexagonal arrays of the gold nanorods and their lamellar accumulation.     

The role of cross-linking structures to the formation of one-dimensional nano-organized polyaniline and their Raman fingerprint

In the present work, the resonance Raman, UV-vis-NIR and scanning electron microscopic (SEM) data of nanorods (about approximately 300 nm in diameter) and nanofibers (about approximately 93 nm in diameter) of PANI are presented and compared. The PANI samples were synthesized in aqueous media with dodecybenzenesulfonic acid (DBSA) and beta-naphtalenesulfonic acid (beta-NSA) as dopants, respectively. The presence of bands at 578, 1400 and 1, 632 cm(-1) in the Raman spectra of PANI-NSA and PANI-DBSA shows that the formation of cross-linking structures is a general feature of the PANI chains prepared in micellar media. It is proposed that these structures are responsible for the one-dimensional PANI morphology formation. In addition, the Raman band at 609 cm(-1) of PANI fibers is correlated with the extended PANI chain conformation.     

手性聚苯胺纳米纤维的电化学制备

采用恒电位电聚合法制备了樟脑磺酸(CSA)掺杂的旋光异构性聚苯胺(PANI)纳米纤维. 用扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 紫外-可见吸收光谱(UV-Vis)和圆二色光谱(CD)对PANI纳米纤维的形貌和光学性质进行表征, 结合电聚合溶液胶束平均粒径和ζ电位的测定, 研究了具有旋光异构性PANI纳米纤维的形成机理和具有增强旋光异构性的原因. 所制备的PANI纳米纤维具有无双螺旋结构, 其形貌不随着苯胺浓度的改变而变化. 不同手性樟脑磺酸掺杂制备的PANI纳米纤维具有镜像对称的旋光异构性, 且具有较高的椭圆偏振率. 这种手性PANI纳米纤维的颜色和旋光性均可通过化学掺杂/去掺杂或电化学掺杂改变氧化还原态而呈现可逆变化.     

Facile controlled synthesis and growth mechanisms of flower-like and tubular MnO2 nanostructures by microwave-assisted hydrothermal method

Birnessite flower-like and α-type tubular MnO(2) nanostructures were selectively synthesized through simple decomposition of KMnO(4) under hydrochloric acid condition by controlling reaction temperature using a microwave-assisted hydrothermal method. The as-prepared samples were characterized in detail by various techniques including X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, Fourier transform-infrared spectroscopy, and Raman scattering spectroscopy. While the growth of flower-like birnessite-MnO(2) might follow a widely accepted Ostwald ripening process, we proposed a formation mechanism of the nanotubular α-MnO(2) based on our evidence, which was assembly of nanorods through an "oriented attachment" process.     

NaOH溶液中CdS纳米棒的水热合成

在NaOH溶液中水热合成了CdS纳米棒, 并探讨了NaOH溶液浓度和反应时间对CdS纳米棒形貌及晶体结构的影响及其可能的生长机理和母液循环可行性. 用粉末X射线衍射(XRD)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)、 高分辨透射电子显微镜(HRTEM)和选区电子衍射(SAED)对CdS纳米棒进行了表征, 并考察了其在可见光照射下光催化降解亚甲基蓝的活性. 结果表明, NaOH溶液是形成棒状形貌的关键因素. 在最优实验条件下, 可获得六方纤锌矿结构CdS纳米棒, 直径约200 nm, 长度可达4 μm. 该纳米棒具有良好的可见光光催化活性.     

Synthesis,characterization and antibacterial properties of a novel nanocomposite based on polyaniline/polyvinyl alcohol/Ag

In this study, a novel nanocomposite based on polyaniline/polyvinyl alcohol/Ag (PANI/PVA/Ag) has been successfully synthesized. The chemical reduction method was used to produce Ag nanoparticle colloidal solution from Ag⁺ ions. The polymerization of aniline occurred in situ for the preparation of polyaniline (PANI) in the presence of ammonium persulfate. With exposure to Ag nanoparticles on the PANI/PVA composite, a new nanocomposite was obtained. The morphology and particle size of the novel nanocomposite was studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) analyses. According to XRD analysis, the size of nanoparticles was found to be in the range of 10–17 nm. SEM images showed the favored shape of nanoparticles as triangle which is a benign shape for antibacterial analysis. The antibacterial activity of the obtained nanocomposite was also evaluated against Gram positive bacteria Staphylococcus aureus (Staph. aureus) and Gram negative Escherichia coli (E. coli) using the paper disk diffusion method. The antibacterial study showed that the PANI/PVA composite did not have a very good antibacterial activity but PANI/PVA/Ag nanocomposites were found to be effective against two bacteria.     

Large‐Area Plasmonic Substrate of Silver‐Coated Iron Oxide Nanorod Arrays for Plasmon‐Enhanced Spectroscopy

One‐dimensional iron oxide materials fabricated on conducting glass substrates and their unique properties make these nanostructures promising candidates for a wide range of applications. Herein, vertically oriented α‐Fe₂O₃ nanorod arrays synthesized under hydrothermal conditions over a large area are described, as an active platform for surface‐enhanced resonance Raman scattering (SERRS) and surface‐enhanced fluorescence (SEF). From scanning electron microscopy images the formation of a homogeneous distribution of vertically oriented rods in a large area is confirmed. For activating the localized surface plasmon resonances, which are responsible for SERRS and SEF, a 6 nm layer of Ag is deposited onto the α‐Fe₂O₃ nanorod arrays by physical vapor deposition to form Ag islands.     

单分散磷酸镧纳米棒的可控制备

采用一步水热法在无模板情况下合成了单一形貌和尺寸均匀的磷酸镧纳米棒,产物分散性好.这种合成方法操作简单、能耗低、合成条件可控,并且重复性很好、可大面积合成.用X射线粉末衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)对磷酸镧的形貌、结构以及相组成进行了分析.结果表明:所合成磷酸镧为单斜相独居石结构;纳米棒直径为15 nm,长度约为几百纳米,具有相当高的纵横比,有望在性能方面得到优化;磷酸镧纳米棒为单晶.对影响磷酸镧纳米棒形成的反应条件如水热温度和水热时间进行了研究,并详细研究了其生长过程.提出了磷酸镧纳米棒的可能生长机制是基于纳米颗粒的定向粘附作用.     

Synthesis and luminescence properties of Eu(III)-doped silica nanorods based on the sol–gel process

Uniform Eu³⁺-doped SiO₂ nanorods were synthesized through a simple sol–gel method using cetyltrimethylammonium bromide (CTAB) as surfactant template and tetraethylorthosilicate as silicon source. X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectrum, scanning electron microscope (SEM), transmission electron microscopy, and photoluminescence spectra were employed to characterize the products in detail. The nanorods have good uniformity and their diameters and lengths are in the range of 200–300 and 500–700 nm through the SEM images, respectively. The formation of the nanorods was studied by taking SEM images after different aging time. The experimental results indicate that CTAB plays a crucial role in the formation of the silica nanorods. The luminescence of Eu³⁺-doped SiO₂ nanorods is dominated by red-emission around 612 nm due to intra-atomic 4f → 4f (⁵D₀ → ⁷F₂₎ transition of Eu³⁺ ions. Furthermore, the effect of doping concentrations of Eu³⁺ ions on the luminescence was investigated.     

WS2纳米棒的合成及其摩擦学性能

以十六烷基三甲基溴化铵(CTAB)作为表面活性剂,利用水热合成法在180℃条件下成功制备出WS2纳米棒。用XRD、SEM、TEM和HRTEM对WS2纳米棒的结构进行表征和分析,并提出了可能的生长机理。将WS2作为润滑油添加剂加到基础油中,用CETR UMT-2摩擦磨损仪测试其摩擦学性能。结果表明:WS2纳米棒作为润滑油添加剂表现出良好的摩擦性能。     

Facile fabrication of rutile monolayer films consisting of well crystalline nanorods by following an IL-assisted hydrothermal route

In this study, rutile films consisting of rectangular nanorods were facilely deposited on glass substrates from strongly acid solution of TiCl₄. The highly ordered array of nanorods was realized in presence of ionic liquid (IL) of [Bmim]Br by following a hydrothermal process. In this process, Degussa P25 nanoparticles served as seeds that were pre-deposited on the substrates to facilitate the array of rutile nanorods. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrum were used to characterize the obtained nanorod films. The measurements showed that the nanorods were rectangular with width of 100-200 nm and length of more than 1 μm, and grew up typically along c-axis to form the arrays against the substrate. The presence of IL was found vital for the formation of rutile nanorods, and the suitable molar ratio of [Bmim]Br to TiCl₄ ranged from 500:1 to 1500:1. The excessive [Bmim]Br may hinder the precipitation of rutile particles.