Institute of Solid State Physics


SS20WS20SS21WS21SS22WS22SS23      Guidelines for Master Students

A Novel Measurement Device for Semi-Volatile Particles
Patrick Christoph Swaschnig
12:00 - 12:25 Wednesday 28 July 2021 online

Video: https://drive.google.com/file/d/1N5G3rehq3PPYROkyboIFGReQVzSJeLFq/view?usp=sharing

Most air pollutants in the atmosphere are known to have a serious impact on the health of living beings and the environment. While many of these pollutants have legal regulations regarding emissions limits, the emission of semi-volatile particles is still unregulated. This talk gives a short introduction to semi-volatile particles and shows a novel measuring principle for their detection. The idea is to heat an aerosol up to 380C and remove all solid particles by a filter. After filtration, the remaining gas is cooled down near room temperature, the aerosol is again filtered and all semi-volatile compounds are collected on the second filter. A virtual prototype was developed, which consists of a heated tube, on the principle of a flow heater and a cooled tube, on the principle of a porous tube diluter. This prototype was used to simulate flow-rates, velocities, temperature- and pressure-distribution in the aerosol. From these results the required geometry, dimensions and dilution rates were calculated. Based on these simulations, the measurement device was constructed in two different realisations, either using gravimetric or optical analysis to detect semi-volatile particles. To perform first proof-of-concept measurements with gravimetric analysis, a porous aluminum tube and two quartz fiber filters were used to build an experimental set-up. Two different aerosol sources namely a soot- and a tetracontane-generator were used for these measurements. It could be shown that the herewith presented principle is capable of detecting semi-volatile particles and paves the way for mobile devices and test bench integrations, with optical rather than gravimetric measuring units. In order to optimize the device for optical analysis, the second filter and the porous tube were integrated in one part that consists of 3D-printed porous ceramics (SiO2), which was also in the scope of this work.