Unique Microphysical Structures of Ultrafine Particles Emitted from Turbofan Jet Engines.

Area of Science:

• Environmental Science
• Aviation Science
• Materials Science

Background:

• Aircraft exhaust emissions are a global concern for human health and climate.
• Volatile particles, not soot, dominate turbofan engine exhaust, but their formation is unclear.

Purpose of the Study:

• To investigate the emission and formation mechanisms of volatile particles from turbofan engines.
• To characterize the microphysical structures of these particles at the engine exit and downstream.

Main Methods:

• Analysis of aircraft exhaust particles at the engine exit and in downstream plumes.
• Characterization of particle microphysical structures using advanced techniques.

Main Results:

• Soot particles constituted less than 1% of downstream exhaust particles.
• The dominant particles were volatile, amorphous, and onion-like, with unique graphene-like structures.
• These particles, 10-20 nm in diameter, likely formed via nucleation and partial pyrolysis, with minimal coagulation.

Conclusions:

• The microphysical structure of these novel volatile particles was identified.
• Their unique structures may influence their physicochemical properties and interactions with the respiratory tract.
• Further research is needed to understand the full health and climate impacts of these emissions.