Characterization of Nano‐Particles Using Laser‐Induced Incandescence
Characterization of Nano‐Particles Using Laser‐Induced Incandescence
复制标题
使用激光诱导白炽光表征纳米颗粒
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
S. Dankers
中科院分区：
文献类型：
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作者：
A. Leipertz;S. Dankers
介绍了激光诱导白炽（LII）作为表征纳米颗粒的有价值的工具。这种光学测量技术基于通过短激光脉冲加热颗粒以及随后检测热辐射。它已成功应用于不同应用领域的烟尘研究，本文以概述的形式进行描述，重点介绍LTT埃尔兰根在过去10年中所做的工作。 在实验室火焰中，烟灰的初级颗粒尺寸、体积浓度和相对聚集体尺寸已经与初级颗粒的数密度相结合来确定。此外，在实验室条件下以及在生产反应器中原位和在线测量了炭黑的初级粒度。用分散在测量室中的不同类型的市售炭黑粉末进行测量，在LII结果和指定的产品性能之间产生了良好的相关性。在炉黑反应器中通过LII测定的颗粒直径与CTAB吸收数非常相关，CTAB吸收数是比表面积的量度。事实证明，LII方法不受所研究的炭黑的聚集体结构的变化的影响。LII信号还包含关于初级颗粒尺寸分布的信息，其可以通过在至少两个不同的时间间隔处评估信号衰减时间来重建。此外，已经确定了柴油发动机内部的碳烟质量浓度，并且在各种发动机条件下在这种发动机的排气中进行在线测量，同时提供关于初级颗粒尺寸、碳烟体积和数量浓度的信息。LII结果显示出与传统测量技术的良好相关性，例如，过滤器烟度测量。除了烟尘测量，主要是其他纳米颗粒如TiO 2或金属颗粒的测试是令人鼓舞的关于这种不同类型的纳米颗粒的表征技术的适用性。
Laser‐induced incandescence (LII) is introduced as a valuable tool for the characterization of nanoparticles. This optical measurement technique is based on the heating of the particles by a short laser pulse and the subsequent detection of the thermal radiation. It has been applied successfully for the investigation of soot in different fields of application, which is described here in the form of an overview with a focus on work done at the LTT‐Erlangen during the last 10 years. In laboratory flames the soot primary particle size, volume concentration, and relative aggregate size have been determined in combination with the number density of primary particles. Furthermore, the primary particle sizes of carbon blacks have been measured in situ and online under laboratory conditions and also in production reactors. Measurements with different types of commercially available carbon black powders, which were dispersed in a measurement chamber yielded a good correlation between LII results and the specified product properties. Particle diameters determined by LII in a furnace black reactor correlate very well with the CTAB‐absorption number, which is a measure for the specific surface area. It turned out that the LII method is not affected by variations of the aggregate structure of the investigated carbon blacks. The LII signal also contains information on the primary particle size distribution, which can be reconstructed by the evaluation of the signal decay time at, at least, two different time intervals. Additionally, soot mass concentrations have been determined inside diesel engines and online measurements were performed in the exhaust gas of such engines for various engine conditions simultaneously providing information about primary particle size, soot volume, and number concentration. The LII results exhibit good correlation with traditional measurement techniques, e.g., filter smoke number measurements. In addition to the soot measurements, primarily tests with other nanoparticles like TiO2 or metal particles are encouraging regarding the applicability of the technique for the characterization of such different types of nanoparticles.