Dependence of Laser-Induced Incandescence on Physical Properties of Black Carbon Aerosols: Measurements and Theoretical Interpretation
Dependence of Laser-Induced Incandescence on Physical Properties of Black Carbon Aerosols: Measurements and Theoretical Interpretation
复制标题
DOI：
10.1080/02786826.2010.484450
复制
发表时间：
2010-01-01
影响因子：
5.2
通讯作者：
Kondo, Yutaka
中科院分区：
文献类型：
--
作者：
Moteki, Nobuhiro;Kondo, Yutaka
我们使用单颗粒烟灰光度计 (SP2)，通过腔内连续波激光器的激光诱导白炽光测量低至 0.5 fg 的单个黑碳 (BC) 颗粒的质量。研究了九种不同类型BC样品的白炽度，为选择合适的BC材料进行SP2校准提供物理基础。我们根据小尺寸参数 x 极限下白炽光的光谱依赖性估计了这些 BC 样品的蒸发温度，其中发射率的光谱依赖性是先验已知的。样品之间的汽化温度差异小于2.2%。对于 x 1 颗粒尺寸范围，SP2 测量的白炽信号的峰值幅度与颗粒质量成线性比例。这种线性比例的斜率与 | 呈正相关。 (m2-1)/(m2+2)|，其中m是BC颗粒的复折射率。对于 x 1 的颗粒，白炽信号峰值幅度随着颗粒质量的增加而增加的速率与颗粒形状的致密性呈负相关，这与解释颗粒形状的发射率的理论预测一致。富勒烯烟灰和东京采样的环境烟灰之间的白炽-BC 质量关系相似，因此表明富勒烯烟灰是环境烟灰 SP2 测量的合适校准标准。
We used a single-particle soot photometer (SP2) to measure the mass of individual black carbon (BC) particles down to 0.5 fg by means of laser-induced incandescence with an intra-cavity, continuous-wave laser. The incandescence of nine different types of BC samples was investigated to provide a physical basis for choosing appropriate BC materials for SP2 calibration. We estimated the vaporization temperatures of these BC samples from the spectral dependence of incandescence at the limit of the small size parameter x, for which spectral dependence of emissivity is known a priori. The vaporization temperatures differed by less than 2.2% among the samples. For the x 1 regime of particle size, the peak amplitude of the incandescence signal measured by the SP2 was linearly proportional to the particle mass. The slopes of such linear proportionality were positively correlated with | (m2-1)/(m2+2)|, where the m is the complex refractive index of the BC particle. For particles in which x 1, the rate of increase in the peak amplitude of the incandescence signal with increasing particle mass was negatively correlated with the compactness of particle shape, consistent with the theoretical prediction of emissivity, which accounts for particle shape. The incandescence-BC mass relationships were similar between fullerene soot and ambient soot sampled in Tokyo, thus suggesting that fullerene soot is a suitable calibration standard for SP2 measurements of ambient soot.