Penetration of monodisperse, singly-charged nanoparticels through polydisperse fibrous filters

Autor(en)

Albert L. Podgorski, Anne Maißer, Wladyslaw Szymanski, Anna Jackiewicz, Leon Gradon

Abstrakt

The article presents experimental results and theoretical analysis of aerosol nanoparticle penetration through fibrous filters with a broad fiber diameter distribution. Four fibrous filters were produced using the melt-blown technique. The analysis of the filters' SEM images indicated that they had log-normal fiber diameter distribution. Five kinds of proteins and two types of silica particles were generated by electrospraying and were then classified using a Parallel Differential Mobility Analyzer to obtain well-defined, monodisperse, singly charged challenge aerosols with diameters ranging from 6.3 to 27.2 nm. Particle penetration through the filters was determined using a water-based CPC. Experimental results were compared first with predictions derived from the classical theory of aerosol filtration. It is demonstrated that it is inappropriate to apply it to the arithmetic mean fiber diameter, as this results in turn in a huge underestimation of nanoparticle penetration. A better, but still unsatisfactory agreement is observed when that theory was used together with the pressure drop equivalent fiber diameter or when the Kirsch model of nonuniform fibrous media was applied. We show that the classical theory applied to any fixed fiber diameter predicts a stronger dependence of nanoparticle penetration on the Peclet number as compared to experimental data. All these observations were successfully explained by using our original partially segregated flow model that accounts for the filter fiber diameter distribution. It was found that the parameter of aerosol segregation intensity inside inhomogeneous filters increases with the increase in particle size, when the convective transport becomes more pronounced in comparison to the diffusive one.

Organisation(en)

Aerosolphysik und Umweltphysik

Externe Organisation(en)

Warsaw University of Technology

Journal

Aerosol Science and Technology

Band

45

Seiten

215-233

Anzahl der Seiten

19

ISSN

0278-6826

DOI

https://doi.org/10.1080/02786826.2010.531300

Publikationsdatum

2011

Peer-reviewed

Ja

ÖFOS 2012

103008 Experimentalphysik, 210006 Nanotechnologie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/d3d1723c-166a-4df0-959f-8008c1dacacd