Non-equivalence of different evaluation algorithms to derive mean particle size from dynamic light scattering data

Various evaluation algorithms are implemented by different manufacturers of dynamic light scattering (DLS) instruments. Users often implicitly assume that the results from the various algorithms are equivalent. This hypothesis was tested using polystyrene latex nanomaterials and two moderately polydisperse silica nanomaterials. Materials were tested in-house using different DLS evaluation algorithms. In addition, the results of an interlaboratory comparison were checked for any indication of the influence of the algorithm. The average particle diameter differed significantly only in few cases between algorithms. Precision, both within-laboratory as well as between-laboratory, was strongly influenced by the algorithm, especially for the more polydisperse silica materials. Results obtained by the cumulants method usually showed the best repeatability and lowest between-laboratory standard deviation. Finally, the results of conversion of the intensity-weighted mean to the volume-weighted mean value were investigated using the data from the intercomparison. The results confirm the theoretical expectations that conversion increases the variation significantly.

FRANKS Katrin;  KESTENS Vikram;  BRAUN Adelina;  ROEBBEN Gert;  LINSINGER Thomas; 

2019-09-26

SPRINGER

JRC106171

1388-0764 (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC106171,   

10.1007/s11051-019-4630-2 (online),