CHEN Shengli，ZHU Xiuqin

College of Chemical Engineering and Environment，China University of Petroleum （Beijing），Beijing 102249， China；

Beijing Nanowize Standard Materials Co. ， Ltd. ， Beijing 102200， China

Abstract

Objective As there is currently no dedicated particle size standard material for dynamic light scattering （DLS） measurement in China， manufacturers and users of particle size analyzers in China primarily rely on standard materials produced by Thermo Fisher Scientific. The study aims to develop particle size standard materials for dynamic light scattering particle size analyzers.

Methods In this study， dynamic light scattering particle size standard materials with nominal particle sizes of 40 nm and 80 nm were synthesized using microemulsion polymerization. A total of 12 institutes used 14 dynamic light scattering particle size analyzers from different manufacturers to determine the particle size values of the developed standard materials.

Results and Discussion The study results showed that the two synthesized polystyrene microspheres exhibited good sphericity and uniform particle size， with stable and homogeneous sample quality. The harmonic mean particle sizes based on scattering light intensity were 40. 0±0. 5 nm and 80±2 nm， respectively. The measurement uncertainties of the assigned values were comparable to those of similar particle size standard materials from the European Community Bureau of Reference and Thermo Fisher Scientific. Among the dynamic light scattering particle size analyzers produced by different manufacturers， the harmonic mean particle sizes based on scattering light intensity showed the best consistency， the mean particle sizes based on scattering light intensity were relatively consistent， the volume-based mean particle sizes showed less consistency， and the number-based mean particle sizes had the poorest consistency. The repeatability of different mean particle sizes measured by the same instrument followed the same order.

Conclusion Two types of dynamic light scattering polystyrene microsphere particle size standard materials， with sizes of 40 nm and 80 nm， were developed. These standard materials exhibit good sphericity， uniform particle size， and stable sample quality.The harmonic mean particle sizes based on scattering light intensity for these two standard materials were determined to be 40. 0±0. 5 nm and 80±2 nm， respectively， with results traceable to the dynamic light scattering method （ISO 22412：2017）. Among the dynamic light scattering particle size analyzers produced by different manufacturers， the harmonic mean particle sizes based on scattering light intensity showed the best consistency， the mean particle sizes based on scattering light intensity were relatively consistent， the volume-based mean particle sizes showed less consistency， and the number-based mean particle sizes had the poorest consistency.

Keywords：polydispersity； standard materials； polystyrene emulsion； dynamic light scattering

DOI：10.13732/j.issn.1008-5548.2024.05.012