...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Combustion and Flame >Evidence of fluorescent carbon nanoparticles produced in premixed flames by time-resolved fluorescence polarization anisotropy
【24h】

Evidence of fluorescent carbon nanoparticles produced in premixed flames by time-resolved fluorescence polarization anisotropy

机译：时间分辨的荧光偏振各向异性在预混火焰中产生的荧光碳纳米颗粒的证据

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

In this work we report on the analysis of combustion-generated nano-organic carbon (NOC) particles by means of time-resolved fluorescence polarization anisotropy (TRFPA). NOC samples were collected in water from non-sooting regions of ethylene/air laminar flames. The size of collected particles was determined with subnanometer accuracy by exploiting femtosecond laser pulses as an excitation source. Moreover, the TRFPA measurements were realized by selecting narrow-wavelength bands within the fluorescence spectrum. With this procedure, the ensemble-averaged size of particles emitting in the selected fluorescence band was determined, to provide additional information on composition and spectroscopic properties of the investigated particles. In particular, the NOC samples consisted of two groups of particles, preferentially emitting in two distinct wavelength bands: smaller particles, with diameter d = 1-1.5 nm, mostly fluorescing in the UV (λ ～ 300-470 nm), and larger particles, d ＞ 2 nm, fluorescing in the visible (λ ～ 490-580 nm). The results of this work strongly support the attribution of UV/visible fluorescence generally detected in flames to nanoparticles. They also evidence that nanoparticles undergo a chemical transformation during the growth process, which produces a red shift in the fluorescence spectrum.
机译：在这项工作中，我们报告了通过时间分辨荧光偏振各向异性（TRFPA）分析燃烧产生的纳米有机碳（NOC）颗粒的方法。 NOC样品是从乙烯/空气层流火焰的非吸气区域采集的。通过利用飞秒激光脉冲作为激发源，以亚纳米级的精度确定收集到的颗粒的大小。此外，TRFPA测量是通过在荧光光谱内选择窄波段实现的。通过此程序，可以确定在所选荧光带中发射的粒子的总体平均大小，以提供有关所研究粒子的组成和光谱性质的其他信息。尤其是，NOC样品由两组颗粒组成，它们优先在两个不同的波长带发射：直径d = 1-1.5 nm的较小颗粒，大部分在紫外线（λ〜300-470 nm）中发荧光，而较大的颗粒，d＞ 2nm，在可见光（λ〜490-580nm）中发荧光。这项工作的结果有力地支持了通常在火焰中检测到的紫外线/可见荧光归因于纳米粒子。他们还证明，纳米粒子在生长过程中会发生化学转化，这会导致荧光光谱发生红移。

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