Formation and characterization of asymmetrical nanoparticle-superstructures

不对称纳米颗粒超结构的形成和表征

• 批准号: 313068956
• 负责人: Professor Dr. Joachim Koetz
• 金额: --
• 依托单位: Leibniz-Institut für Polymerforschung Dresden (IPF)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/313068956?language=en
• 关键词: Formation; characterization; asymmetrical; nanoparticle; superstructures

The aim of the project is to synthesize and characterize asymmetric nanoparticle superstructures on basis of triangular/hexagonal gold nano-platelets. Anionic vesicles are transformed into a tube-like network structure by adding PalPhBisCarb, i.e. Poly(N,N-diallyl-N,N-dimethylammonium-alt-3,5-bis-carboxyphenylmaleamincarboxylate). The resulting network structure is used as a template phase for the formation of gold-nanoplatelets. The specific tube-like network of the template phase enables the growth of asymmetric flat hexagonal/triangular platelets. Due to the presence of the polyampholyte, i.e. PalPhBisCarb, the gold nanoplatelets show a negatively charged surface. Therefore, the adsorption of oppositely charged cationic nanoparticles in a size range of 2-20 nm (Ag, Au, CdS, Fe3O4) becomes possible. These spherical particles have been formed in a separate nucleation process and their stability is achieved by covering their surface with a polycation, i.e. poly(ethylenimine). Due to predominantly electrostatic interactions between negatively charged gold nano-platelets and positively charged spherical nanoparticles, but also by a conjugation via DNA strands or mercapto groups supramolecular architectures can be created in a next step. The advantage of this strategy is to create tuneable special optical and magnetic properties of the highly ordered architectures in dependence on the adsorbed spherical nanoparticles. Therefore, highly ordered anisotropic structures on the nanometerscale with antibacterial, magnetic or opto-electronical properties becomes available. Because the size range for spherical particles in the order of 2-20 nm is tuneable in dependence on the template used, e.g. polyelectrolyte-modified microemulsions, a variation of the properties of the assemblies is not only possible by the kind of the adsorbed nanoparticle but also by their particle size. Asymmetric Flow - Field Flow Fractionation (AF-FFF), dynamic and electrophoretic light scattering measurements in combination with UV-vis spectroscopy are applied for characterizing size and charge of the particles. For a morphological characterization of the triangular and supramolecular architectures High Resolution Transmission Electron Microscopy (HRTEM) will be applied. Because of the state-of-the-art equipment in the research group Koetz (EELS, EDX elemental analysis, tomography) of HRTEM, the adsorption of single nanoparticles at the surface of the matrix is directly provable. Finally, it has to be stated here that the project is exceeding the state of present knowledge because a unique monodisperse distribution in asymmetric assemblies could not be realized until now. Therefore, the project opens a door to further activities in the field of multifunctional nano-assemblies with extraordinary properties.

该项目的目的是在三角形/六边形金纳米片的基础上合成和表征不对称纳米颗粒超结构。通过加入PalPhBisCarb，即聚（N，N-二烯丙基-N，N-二甲基铵-alt-3，5-双-羧基苯基马来酸胺羧酸酯），阴离子囊泡被转化成管状网络结构。所得的网络结构用作形成金纳米片的模板相。模板相的特定管状网络使得能够生长不对称的平坦六边形/三角形片晶。由于存在两性聚电解质，即PalPhBisCarb，金纳米片显示带负电荷的表面。因此，在2-20 nm的尺寸范围内的带相反电荷的阳离子纳米颗粒（Ag、Au、CdS、Fe 3 O 4）的吸附成为可能。这些球形颗粒已经在单独的成核过程中形成，并且它们的稳定性通过用聚阳离子（即聚（乙烯亚胺））覆盖它们的表面来实现。由于带负电荷的金纳米片和带正电荷的球形纳米颗粒之间的主要静电相互作用，而且通过经由DNA链或巯基的缀合，可以在下一步中产生超分子结构。这种策略的优点是根据吸附的球形纳米颗粒来创建高度有序结构的可调谐的特殊光学和磁性。因此，在纳米尺度上具有抗菌、磁性或光电性能的高度有序的各向异性结构成为可能。由于球形颗粒的尺寸范围在2-20 nm的量级，可根据所用的模板（例如聚电解质改性的微乳液）进行调节，因此组装体的性质的变化不仅可能取决于吸附的纳米颗粒的种类，而且还可能取决于它们的粒度。不对称流场流分级（AF-FFF），动态和电泳光散射测量与紫外-可见光谱相结合，用于表征颗粒的大小和电荷。对于三角形和超分子结构的形态表征，将应用高分辨率透射电子显微镜（HRTEM）。由于高分辨透射电镜的Koetz研究小组（EELS、EDX元素分析、断层扫描）拥有最先进的设备，可以直接证明单个纳米颗粒在基质表面的吸附。最后，这里必须指出的是，该项目超出了目前的知识状态，因为直到现在才能实现不对称组件中的独特单分散分布。因此，该项目为具有非凡性能的多功能纳米组装领域的进一步活动打开了大门。