In-situ aerosol nanoparticle characterization by small angle X-ray scattering at ultra-low volume fraction.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30850597.
- Also identified by DOI 10.1038/s41467-019-09066-4 and PMC identifier 6408461.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
State-of-the-art aerosol nanoparticle techniques all have one feature in common: for analysis they remove the nanoparticles from their original environment. Therefore, physical and chemical properties of the particles might be changed or cannot be measured correctly. To overcome these shortcomings, we apply synchrotron based small angle X-ray scattering (SAXS) as an in-situ measurement technique. Contrasting other aerosol studies using SAXS, we focus on particle concentrations which allow direct comparison to common aerosol nanoparticle analyzers. To this end, we analyze aerosol nanoparticles at ambient pressure and concentrations of slightly above ~10<sup>6</sup> cm<sup>-3</sup>. A differential mobility particle sizer (DMPS) is operated in parallel. We find that SAXS enables measurement of the primary particles and the aggregates, whereas the DMPS detects only aggregates. We conclude that in-situ nanoparticle characterization with ultra-low volume fractions of ~10<sup>-10</sup> is feasible with SAXS. Our technique opens up a doorway to the in-situ analysis of aerosol nanoparticles under atmospheric conditions.