共查询到19条相似文献,搜索用时 938 毫秒
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闫昭 《原子与分子物理学报》2016,33(6):1011-1016
本文通过半胱氨酸分子诱导金纳米棒自组装形成一维线性链状结构,利用停留装置观察了不同手性的半胱氨酸分子(L/D-半胱氨酸)诱导金纳米棒自组装的动力学过程.通过调控CTAB浓度,首次发现在组装速率很快的情况下,L-半胱氨酸分子诱导金纳米棒自组装的组装速率慢于D-半胱氨酸分子.而在组装速率较慢的情况下,这种情况不存在.通过分析揭示了为什么在慢速动力学和快速动力学会出现这种差异.并对在快速动力学下不同手性分子在诱导纳米颗粒组装上不同动力学行为作出讨论.这一工作可能为进一步解释生命的单一手性现象提供线索. 相似文献
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闫昭 《原子与分子物理学报》2017,34(6)
摘要:本文通过半胱氨酸分子诱导金纳米棒自组装形成一维线性链状结构,利用停留装置观察了不同手性的半胱氨酸分子(L/D-半胱氨酸)诱导金纳米棒自组装的动力学过程。通过调控CTAB浓度,首次发现在组装速率很快的情况下,L-半胱氨酸分子诱导金纳米棒自组装的组装速率慢于D-半胱氨酸分子。而在组装速率较慢的情况下,这种情况不存在。通过分析揭示了为什么在慢速动力学和快速动力学会出现这种差异。并对在快速动力学下不同手性分子在诱导纳米颗粒组装上不同动力学行为作出讨论。这一工作可能为进一步解释生命的单一手性现象提供线索。 相似文献
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采用元胞动力学和布朗动力学联用方法研究了振荡场作用下两嵌段共聚物/均聚物/纳米棒混合体系的自组装相行为.通过计算模拟,探讨了振荡场的振幅和频率对混合体系相形貌形成和演化的影响.研究发现振荡场对体系有序结构的形成和转变有重要作用,随着外加振荡场频率的增大,混合体系形貌从平行于场方向的条纹结构过渡到斜层状结构再转变为垂直于场方向的条纹结构.进一步分析了振荡场作用下体系畴尺寸的演化及纳米棒取向角的变化情况.研究结果为制备和调控聚合物纳米复合材料有序结构提供了新的方法和参考. 相似文献
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等离激元金属纳米结构中的Fano共振,由于其在超灵敏传感、超材料、光开关和非线性光学器件等方面的潜在应用而引起了广泛的关注。但在单颗粒尺度下单个金属纳米二聚体结构的Fano共振的实验研究仍然很少。本研究基于单颗粒光谱技术从实验上探讨了二聚体结构产生的Fano共振现象。利用种子生长法制备了等离激元共振峰分别在1 060 nm和700 nm的一长一短金纳米棒,通过L-半胱氨酸分子的静电吸附自组装构建首尾相连的金纳米棒二聚体结构,在暗场显微系统中表征了金纳米棒二聚体耦合前后的散射光谱。结果表明,短金纳米棒的明偶极模式与长金纳米棒的暗四极模式间的相消干涉在660 nm处产生了明显的Fano共振谷,同时基于有限差分时域(FDTD)方法的理论模拟散射光谱与实验结果能够较好地符合。这种自组装金纳米棒二聚体在等离激元传感和探测等方面具有广阔的应用前景。 相似文献
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提出了一种基于金纳米棒自组装的促进和抑制检测汞离子的方法.在合适的实验条件下,当金纳米棒胶体溶液中加入还原性谷胱甘肽(GSH)时,金纳米棒因Au-S键的形成,通过氢键和静电相互作用发生头对头(End to End)的自组装.当以上体系中加入汞离子时,这种头对头的自组装会被打破,金纳米棒重新呈分散状态.这种方法的最低检测限为1nmol/L,检测范围为1nmol/L-100μmol/L.该汞离子检测方法特异性强、灵敏度高且检测的浓度范围比较大,有望广泛用于水环境中汞离子的检测. 相似文献
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报道了一种单分散“核-卫星”纳米金簇状结构的构造方法,不但可以有效调节卫星粒子的数目,还能实现核与卫星粒子间距离的准确控制. 利用DNA分子高度可控的程序化自组装性能,通过合理控制组装过程中核与卫星粒子表面的DNA修饰密度以及不同金纳米粒子的化学计量比,实现了单分散核-卫星结构的高产率组装,结合使用凝胶电泳这一高效的纳米分离技术实现了目标产物的分离. 该方法保证了卫星粒子表面极低的DNA覆盖率,使其与蛋白分子中的巯基基团具有较强的化学亲和作用,使得金纳米粒子在蛋白功能化石墨烯表面的二维层次化自组装得以实现. 相似文献
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纳米结构的力学性能是纳米超微型器件设计的基础,分子动力学是研究纳米结构力学行为的有效方法.本文采用镶嵌原子方法模拟金属铜纳米棒的弯曲力学行为.计算结果表明由于尺寸效应和表面效应的影响,在纳观尺度下纳米结构表现出与宏观尺度下完全不同的力学特征.金属纳米棒弯曲力学过程分为初始变形迟滞阶段、线弹性变形阶段和塑性变形阶段.塑性变形阶段表现出“刚化”、“台阶”和较强的延性等特征.
关键词:
纳米结构
纳米棒
弯曲性能
分子动力学 相似文献
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We investigated the plasmonic resonance enhanced two-photon photopolymerization (PETPP) using the isolated chemical synthesized
gold nanorods for fabrication of polymer/metal nanocomposites. The isolated gold nanorods with the plasmonic resonance band
around 750 nm covered by photoresist were irradiated by a femtosecond laser with the wavelength of 780 nm. The PETPP trigged
by the plasmonic resonance enhancement of gold nanorods was localized only in the distance smaller than 30 nm from the surface
of gold nanorods, which matched the distance of plasmonic resonant enhanced field of the gold nanorod. The shapes of obtained
polymer/gold nanocomposites were changed from the “dumbbell” to the “ellipsoid” with the increase of laser irradiating intensity
used for PETPP. This study would provide a potential method for fabricating the plasmonic nanomaterials and nanostructures
of polymer/metal nanocomposites, which could be expected to be applied in the emerging fields such as nanophotonics, nanobiosensor,
nanolithography. 相似文献
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Noble metallic nanostructures exhibit special optical properties resulting from excitation of surface plasmons. Among the various metallic nanostructures, nanorods have attracted particular attention because of their unique and intriguing shape-dependent plasmonic properties. Nanorods can support transverse and longitudinal plasmon modes, the latter ones depending strongly on the aspect ratio of the nanorod. These modes can be routinely tuned from the visible to the near-infrared spectral regions. Although nanorods have been investigated extensively, there are few studies devoted to nanostructures deviating from the nanorod shape. This review provides an overview of recent progress in the development of two kinds of novel quasi-one-dimensional silver nanostructures, nanorice and nanocarrot, including their syntheses, crystalline characterizations, plasmonic property analyses, and performance in plasmonic sensing applications. 相似文献
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《中国物理 B》2019,(1)
Multiple Fano resonances of plasmonic nanostructures have attracted much attention due to their potential applications in multicomponent biosensing. In this paper, we propose a series of hybridized nanostructures consisting of a single nanoring and multiple nanorods to generate multiple Fano resonances. One to three Fano resonances are achieved through tuning the number of nanorods. The interaction coupling process between different components of the nanostructures is recognized as the mechanism of multiple Fano resonances. We also theoretically investigate the applications of the produced multiple Fano resonances in refractive index sensing. The specific properties of multiple Fano resonances will make our proposed nanostructures beneficial to high-sensitivity biosensors. 相似文献
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We demonstrate coded self-assembly in nanostructures using the code seeded at the component level through computer simulations.
Defects or cavities occur in all natural assembly processes including crystallization and our simulations capture this essential
aspect under surface minimization constraints for self-assembly. Our bottom-up approach to nanostructures would provide a
new dimension towards nanofabrication and better understanding of defects and crystallization process.
相似文献
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Two‐Dimensionally Ordered Plasmonic and Magnetic Nanostructures on Transferable Electron‐Transparent Substrates
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Abhinav Malasi Jingxuan Ge Connor Carr Hernando Garcia Gerd Duscher Ramki Kalyanaraman 《Particle & Particle Systems Characterization》2015,32(10):970-978
Discovery of new plasmonic behaviors from nanostructured materials can be greatly accelerated by the ability to prepare and characterize their near‐field behaviors with high resolution in a rapid manner. Here, an efficient and cost‐effective way is reported to make 2D periodic nanostructures on electron‐transparent substrates for rapid characterization by transmission electron microscopy. By combining nanosphere lithography with a substrate float‐off technique, large areas of electron‐transparent periodic nanostructures can be achieved. For this study, the synthesis of plasmonic nanostructures of Ag, magnetic nanostructures of Co, and bimetallic nanostructures of Ag–Co are investigated. Characterization of the materials by a combination of transmission electron microscopy, far‐field optical spectroscopy, and magnetization measurements reveals that this new approach can yield useful nanostructures on transparent, flexible, and transferable substrates with desirable plasmonic and/or magnetic properties. 相似文献
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Gold nanorods with the longitudinal plasmonic resonance peak position up to 1200?nm are prepared using an improved seedless synthetic technique. In this method, dopamine is employed as the weak reducer, whereas cetyltrimethylammonium bromide and sodium oleate are used as the binary surfactant mixture. Gold nanorods produced at various amounts of silver nitrate and hydrochloric acid were characterized by visible-near-infrared spectroscopy and scanning electron microscopy. Results show that the sizes, length-to-width aspect ratios, and the corresponding longitudinal surface plasmon resonance peaks of the synthesized gold nanorods can be tuned by altering the silver nitrate and hydrochloric acid amounts. The present method provides a new procedure for fabrication of gold nanorods with a broad range of plasmonic resonance peaks, which has a great potential for applications such as photothermal therapy and sensing. 相似文献
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Plasmonic Octahedral Gold Nanoparticles of Maximized Near Electromagnetic Fields for Enhancing Catalytic Hole Transfer in Solar Water Splitting
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Cheon Woo Moon Seon Yong Lee Woonbae Sohn Dinsefa Mensur Andoshe Do Hong Kim Kootak Hong Ho Won Jang 《Particle & Particle Systems Characterization》2017,34(1)
Due to their localized surface plasmon resonances in visible spectrum, noble metal nanostructures have been considered for improving the photoactivity of wide bandgap semiconductors. Improved photoactivity is attributed to localized surface plasmon relaxations such as direct electron injection and resonant energy transfer. However, the details on the plasmonic solar water splitting through near electromagnetic field enhancement have not been fully understood. Here, the authors report that shape‐controlled gold nanoparticles on wide bandgap semiconductors improve the water‐splitting photoactivity of the semiconductors with over‐bandgap photon energies compared to sub‐bandgap photon energies. It is revealed that hot hole injection into the oxygen evolution reaction potential is the rate‐limiting step in plasmonic solar water splitting. The proposed concept of photooxidation catalysts derived from an ensemble of gold nanoparticles having sharp vertices is applicable to various photocatalytic semiconductors and provides a theoretical framework to explore new efficient plasmonic photoelectrodes. 相似文献
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ZnO and ZnMgO nanostructures were synthesized on Si (1 0 0) substrates with the assistance of a gold catalyst, using a thermal evaporation method with a ZnO/ZnMgO compound as the source material. The substrates were placed in different temperature zones. ZnO nanostructures with different morphologies and different compounds were obtained at different substrate temperatures. Nanostructures with nanorods and nanosheets morphologies formed in the low and high temperature zones, respectively. The nanorods grown in the low temperature zone had two phases, hexagonal and cubic. Energy dispersive X-ray (EDX) results showed that the nanorods with a cubic shape contained more Mg in comparison to the nanowires with a hexagonal shape. We found that the substrate temperature and the gold catalyst were two key factors for the doping of Mg and the formation of nanostructures with different morphologies. Room temperature photoluminescence spectroscopy showed a blue-shift for the nanostructures with the nanorods morphology. This shift could be attributed to Mg effects that were detected in the nanorods. 相似文献
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Michael Barth Stefan Schietinger Tim Schröder Thomas Aichele Oliver Benson 《Journal of luminescence》2010,130(9):1628-12578
Nitrogen-vacancy (NV) defect centers in diamond have recently emerged as promising candidates for a number of applications in the fields of quantum optics and quantum information, such as single photon generation and spin qubit operations. The performance of these defect centers can strongly be enhanced through coupling to plasmonic and photonic nanostructures, such as metal particles and optical microcavities. Here, we demonstrate the controlled assembly of such hybrid structures via manipulation with scanning near-field probes. In particular, we investigate the plasmonic enhancement of the single photon emission through coupling to gold nanospheres as well as the coupling of diamond nanocrystals to the optical modes of microsphere resonators and photonic crystal cavities. These systems represent prototypes of fundamental nanophotonic/plasmonic elements and provide control on the generation and coherent transfer of photons on the level of a single quantum emitter. 相似文献