2017 Volume 34 Pages 168-182
Size characterization of nanoparticles has gained wide concerns in the past decades, but it remains a challenge for measurement in suspensions up to now. The extremely small scales of particle size result in great difficulty for traditional static light scattering method and optical imaging. In addition to the electron microscopy techniques, the dynamic light scattering (DLS) method is another widely used technique for laboratory analysis of samples. Moreover, the ultrasonic attenuation spectroscopy (UAS) technique is also being developed rapidly to provide an alternative method for nanoparticle sizing. This paper focuses on the latest development in the above two technologies for nanoparticle size characterization. As for the former, advances about the image-based DLS technology in recent years are reviewed, including three different kinds of data processing methods and corresponding measuring experiments using standard polystyrene particles. Methodology principles, models and experimental setup were also reviewed for the latter UAS technology. Samples of the same nanoscale silver particles were tested by the above two methods, as well as by transmission electron microscopy. A sample of Antimony Tin Oxide (ATO) nanoparticles has also been adopted for measurements and comparisons. Relatively consistent results can be found by comparing the particle sizes or distributions with various methods. The dramatically reduced measurement time in image-based DLS indicates the potential for real-time and in-situ nanoparticle sizing. UAS also provides a suitable way for nanoparticle size characterization at high concentrations.
