多成分微粒光學彈性散射與非彈性散射特性之研究

The Study of Elastic and Inelastic Scattering Properties of Multicomponent Particle

張元義(Yuan-Yi Chang)

指導教授 ： 林文印

國立臺北科技大學/工程學院/工程科技研究所/博士(2014年)

https://doi.org/10.6841/NTUT.2014.00612

摘要

本研究為探討單一多成分微粒之光學彈性散射與非彈性散射特性，建構一便利且合適的實驗系統與方法，並且藉由比對實驗與米氏散射理論模式模擬之結果，探究單一微粒光學特性，同時也討論微粒尺寸、折射率、以及化學成分之組成對於彈性散射與非彈性散射之影響。
本研究分為三大部分，第一部分為利用米氏理論模擬並比較硫酸銨、硝酸銨、以及硫酸銨與硝酸銨混合物之光學特性。第二部分為建立單一微粒懸浮系統，並結合多角度散光強度量測系統及拉曼光譜儀，量測、比較不同粒徑大小之聚甲基丙烯酸甲酯 (PMMA)、碳 (carbon)微粒之光學特性。第三部分為探討單一多成分微粒之光學特性，根據本研究的第二部分之基礎，藉由氣膠懸浮器結合多角度散光強度量測系統及拉曼光譜儀，來測量微粒在不同角度之彈性散射特性與多成分微粒之非彈性散射特性，同時也討論多成分微粒之光學折射率與粒徑大小對光學特性之影響。
研究結果顯示，本實驗系統量測之結果可趨近米氏理論之數值模擬的趨勢。實驗結果也發現，當使用氣動粒徑來取代等體積直徑時，可能會導致模式模擬與實際量測結果出現顯著差異。此外，使用加權的方法來計算多成分微粒之光學折射率，可能會因為多成分微粒之混合情形，造成模式與實驗結果比對之差異性。

關鍵字

米氏散射 ； 多成分微粒 ； 彈性散射 ； 非彈性散射 ； 氣膠懸浮系統

並列摘要

In this study, it introduced a convenient experimental method and the comparison with Mie scattering model that could obtain the scattering function of single multicomponent particle as well as capture the elastic and inelastic scattering characteristics related to particle size, refractive index, and chemical composition.
In the first part of this study, Mie scattering model were used to simulate and compare the optical property of ammonia sulfate, ammonia nitrate, and ammonia sulfate/ammonia nitrate particle. In the second part, the Particle Levitation System, multi-angle scattering intensity measurement system, and Ramen spectroscopy were used to measure and compare the optical property of Polymethyl methacrylate (PMMA) and carbon particle with different size. In the third part, the multicomponent particle was detected. Moreover, the multicomponent particle, particle levitation system, multi-angle scattering intensity measurement system, and Ramen spectroscopy were also used to measure and compare the elastic scattering and inelastic scattering properties as well as discuss the influences of refraction index and particle size of multicomponent particle.
The experimental results indicated that the measurements of single particle scattering were in approximate trend with numerical simulations. The results also implicated that the simulation might result in significant error in the overall scattering because of using aerodynamic diameter to replace equivalent volume diameter. Besides, it might be presented some problems while the refractive index was usually estimated as the volume-weighted average method for particles of mixed chemical composition.

並列關鍵字

Mie scattering ； Multicomponent particle ； Elastic scattering ； Inelastic scattering ； Particle Levitation system

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