...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical chemistry chemical physics: PCCP >Morphology and optical responses of SERS active π-conjugated poly(N-ethyl-2-ethynylpyridinium iodide)/Ag nanocomposite systems
【24h】

Morphology and optical responses of SERS active π-conjugated poly(N-ethyl-2-ethynylpyridinium iodide)/Ag nanocomposite systems

机译：SERS活性π共轭聚（N-乙基-2-乙炔基吡啶碘化物）/ Ag纳米复合材料的形貌和光学响应

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The influence of the poly(N-ethyl-2-ethynylpyridinium iodide) (PEEP-I) concentration on the morphology and optical properties of nanocomposite systems prepared by mixing the polymer solution with a hydrosol of ca. 9 nm Ag nanoparticles (NPs) was investigated by a combination of surface plasmon extinction (SPE) measurements, transmission electron microscope (TEM) imaging and surface-enhanced Raman spectroscopy (SERS). The PEEP-I concentration was found to have a strong impact on the assembly of Ag NPs and, consequently, on the optical responses of the composite systems. At low polymer concentrations in the composite (corresponding to ca. 50-1800 monomer units/NP), the formation of fractal aggregates was observed. In particular, the average fractal dimension D = 1.9 ± 0.1 was determined for aggregates in the system with 5 x 10~(-6) M polymer concentration. By contrast, in systems with polymer concentrations higher than about 1 x 10~(-5) M, relatively small aggregates of Ag NPs with large interparticle distances were formed. The differences in the morphology of the composite systems with various polymer concentrations manifested themselves clearly in their SPE spectra. Furthermore, upon optical excitation with appropriate wavelengths (488.0 and 514.5 nm), the fractal aggregates acted as carriers of "hot spots", i.e. strong, localized, nanoscale optical fields, from which intense and well resolved SERS spectra of the polymer were obtained.
机译：聚（N-乙基-2-乙炔基吡啶鎓碘化物）（PEEP-1）浓度对通过将聚合物溶液与约1的水溶胶混合而制备的纳米复合系统的形貌和光学性质的影响。通过表面等离激元消光（SPE）测量，透射电子显微镜（TEM）成像和表面增强拉曼光谱（SERS）的组合研究了9 nm Ag纳米颗粒（NPs）。发现PEEP-1浓度对Ag NP的组装有强烈影响，因此对复合体系的光学响应有很大影响。在复合物中低的聚合物浓度下（相当于约50-1800单体单元/ NP），观察到分形聚集体的形成。特别是，对于聚合物浓度为5 x 10〜（-6）M的系统中的聚集体，确定了平均分形维数D = 1.9±0.1。相比之下，在聚合物浓度高于约1 x 10〜（-5）M的系统中，形成了颗粒间距离较大的相对较小的Ag NP聚集体。具有不同聚合物浓度的复合体系的形态差异在其SPE光谱中清晰可见。此外，在适当波长（488.0和514.5nm）的光激发下，分形聚集体充当“热点”的载体，即强的，局部的，纳米级的光场，从中获得强的和良好分辨的聚合物SERS光谱。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号