Thermophoretic Sensors for Combustion Formed Nanoparticles

The emission of carbon nanoparticles from both stationary and automotive combustion systems has long been of concern for their negative effects on the human health, on the environment and for the climate change. In addition, the formation and the emission of carbonaceous aerosols is a clear marker of a not efficient combustion process [1]. Combustion formed carbon nanoparticles are typically divided into two major classes: a nucleation mode whose sizes are of the order of 2-3 nm and a primary soot mode whose sizes span from few nanometers up to tens of nanometers [2]. In this work, thermocouple particle densitometry (TPD) technique [3] has been carried out to detect nanoparticles produced in a slightly sooting laminar premixed flame and to characterize both particle emissivity and total particulate volume fraction. In addition, thermophoretic sampling has been adopted for the collection and electrical characterization of combustion nanoparticles with different graphitization degree, demonstrating that such an approach can be useful for the development of conductometric combustion aerosol sensors.