Novel electric thermophoretic sampling device with highly repeatable characteristics

Area of Science:

• Engineering
• Chemistry
• Physics

Background:

• Nanoparticle aggregates in flames and aerosols are crucial for understanding combustion and atmospheric processes.
• Accurate in-situ sampling is essential for characterizing these particles.
• Existing methods may lack precision or applicability across diverse environments.

Purpose of the Study:

• To introduce a novel thermophoretic sampling device for nanoparticle aggregates.
• To detail the design, operation, and performance of the sampling probe.
• To evaluate the device's impact on flame characteristics and its effectiveness in sampling soot.

Main Methods:

• Utilized a tubular electric linear motor for precise probe motion control.
• Employed oscilloscope measurements and high-speed recordings to assess spatial and temporal performance.
• Investigated flame disturbances and sampled soot aggregates using ethene and ethyne fuels.

Main Results:

• Achieved high precision motion with minimal vibrations (3 ms residence time, 4.1 m/s max velocity).
• Demonstrated low positional deviations (axial: 0.14 mm, horizontal: 0.02 mm, vertical: 0.36 mm).
• Observed minor flame disturbances (max 20% change in soot radiance) and obtained satisfying morphological soot properties.

Conclusions:

• The novel thermophoretic sampling device offers high precision and minimal invasiveness for nanoparticle aggregate analysis.
• The device is suitable for diverse applications including flames, particle-laden gases, and aerosols.
• Results demonstrate the device's capability for accurate in-situ characterization of soot properties.