Detection of combustion formed nanoparticles
Detection of combustion formed nanoparticles
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DOI：
10.1016/s0045-6535(02)00718-x
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发表时间：
2003-06-01
期刊：
影响因子：
8.8
通讯作者：
D'Alessio, A
中科院分区：
文献类型：
--
作者：
Sgro, LA;Basile, G;D'Alessio, A
紫外可见消光和散射和两个额外的原位采样技术：原子力显微镜（AFM）和微分迁移率分析（DMA）被用来跟踪火焰中形成的颗粒的演变。选择这些颗粒尺寸测量技术是因为它们对检测初始颗粒的灵敏度，初始颗粒的直径d < 5 nm，太小而不能用典型的颗粒测量仪器观察到。通过原子力显微镜和DMA确定的颗粒尺寸与通过原位光学测量确定的尺寸进行了很好的比较，这表明对紫外可见光信号的解释相当好，并强烈显示了d = 2-4 nm颗粒的存在。紫外-可见消光测量也用于确定实际燃烧系统排气中d = 2-4 nm颗粒的浓度。一个数值模型，能够重现实验观察到的低凝聚率的纳米粒子相对于烟灰颗粒，是用来研究在燃烧室和排气系统的2-4 nm的颗粒生存的排气或生长到更大的尺寸的操作条件。燃烧产生的纳米颗粒被怀疑会影响人类和环境健康，因为它们对水的亲和力、小尺寸、低凝结速率和大的表面积/重量比。从燃烧收集的水溶胶中的烟尘颗粒分离纳米颗粒的能力可能有助于未来通过各种技术和毒理学测定进行分析。(C)2003爱思唯尔科技有限公司版权所有。
UV-visible extinction and scattering and two extra situ sampling techniques: atomic force microscopy (AFM) and differential mobility analysis (DMA) are used to follow the evolution of the particles formed in flames. These particle sizing techniques were chosen because of their sensitivity to detect inception particles, which have diameters, d < 5 mn, too small to be observed with typical particle measurement instrumentation. The size of the particles determined by AFM and DMA compares well with the size determined by in situ optical measurements, indicating that the interpretation of the UV-visible optical signal is quite good, and strongly showing the presence of d = 2-4 nm particles. UV-visible extinction measurements are also used to determine the concentration of d = 2-4 nm particles at the exhausts of practical combustion systems. A numerical model, able to reproduce the experimentally observed low coagulation rate of nanoparticles with respect to soot particles, is used to investigate the operating conditions in the combustion chamber and exhaust system for which 2-4 nm particles survive the exhaust or grow to larger sizes. Combustion generated nanoparticles are suspected to affect human and environmental health because of their affinity for water, small size, low rate of coagulation, and large surface area/weight ratio. The ability to isolate nanoparticles from soot particles in hydrosols collected from combustion may be useful for future analysis by a variety of techniques and toxicological assays. (C) 2003 Elsevier Science Ltd. All rights reserved.