Efficiency of Various Devices and Theories to Collect Nanoparticles Directly onto

描述（由申请人提供）：透射电子显微镜（TEM）是一种非常有用的技术，用于评估纳米颗粒形态，元素分析，颗粒计数和大小。这项技术最近已成为表征空气中纳米颗粒暴露的必要工具。本研究的具体目的是比较使用TEM扩散采样器（TDS）、静电沉淀采样器（EPS）和热电泳采样器（TPS）直接将机载工程纳米颗粒（ENPs）沉积到网格上进行材料表征的可用方法。研究目标包括：尺寸分布、沉积均匀性和易用性的比较。将产生测试纳米颗粒气溶胶，样品将与使用每种方法的三个设备并排收集，以及纳米扫描SMPS （TSI型号3910,10-420 nm）和光学粒子计数器（OPC） （TSI型号3330,300 nm- 10¿m）记录颗粒浓度。实验将在普渡大学的Birck纳米技术洁净室实验室进行。本研究将验证以下假设：(1)基本气溶胶理论可用于预测粒子在TEM网格上的聚集；(2)TPS比TDS和EPS更有效地将小于200 nm的颗粒直接收集到TEM网格上，EPS比TPS和TDS更有效地收集200 nm - 10¿m的颗粒，而两种技术都不能有效地收集大于1¿m的颗粒；(3)三种机制收集的纳米颗粒随机分布在网格表面上。这项研究的结果将为充分利用采样器收集纳米粒子提供信息丰富的技术结果。此外，该结果将为进一步修改现有采样器或开发新设计的采样器提供输入，该采样器可以为未来的研究提供更好的性能。

DESCRIPTION (provided by applicant): Transmission electron microscope (TEM) is a very useful technique for evaluating nanoparticle morphology, for elemental analysis, and for particle counting and sizing. This technique has recently become a required tool to characterize exposure to airborne nanoparticles. The specific aim of this proposed research is to compare the available methods using TEM diffusive sampler (TDS), electrostatic precipitation sampler (EPS) and thermophoretic sampler (TPS) for directly depositing airborne engineered nanoparticles (ENPs) onto grids for material characterization. Research objectives include: comparison of size distributions, deposition uniformity and the ease of use. Test nanoparticle aerosols will be generated and samples will be collected side-by-side with three devices using each method, along with the NanoScan SMPS (TSI Model 3910, 10-420 nm) and Optical Particle Counter (OPC) (TSI Model 3330, 300 nm- 10 ¿m) to record the particle concentration. Experiments will be performed in the Birck Nanotechnology cleanroom laboratory at Purdue University. This research will test the following hypotheses: (1) Basic aerosol theory can be used to predict particle collection onto TEM grids; (2)TPS is more efficient than TDS and EPS for collecting particles less than 200 nm directly onto a TEM grid, EPS is more efficient than TPS and TDS for collecting particles from 200 nm - 10 ¿m, and none of the techniques are efficient at collecting particles larger than 1 ¿m; and (3) Nanoparticles collected by all three mechanisms are randomly distributed across a grid surface. The results from this research will provide informative technical results to develop the adequate use of samplers for collecting nanoparticles. In addition, the results will provide the input for further modifications to existin samplers or the development of a newly-designed sampler which can provide better performance for future research.