Colloidal dispersions of nanomaterials are often polydisperse, particularly early on in their early development, due to factors relating to synthetic control, dispersion efficiency and instability during storage. As their targeted applications often depend on their dimensional parameters, monitoring changes in the size and aspect ratio distribution between multiple samples or the same sample over time is paramount. The most commonly employed methods in the literature, such as dynamic light scattering, only estimate the first or second moment of narrow distributions. In this work, we introduce a rapid analysis employing single particle tracking (SPT) demonstrate its ability to probe solution particle distributions of common preparations of single-walled carbon nanotubes (SWCNTs) and graphene oxide (GOx) at different stages of centrifugation. Our results demonstrate that SPT is able to measure distribution changes throughout the course of material preparation, and consequently, dispersion quality and the effectiveness of current protocols. Methodological comparison with analytical centrifugation (AUC) reveals that SPT is a facile analytical method with minimal biases and expertise required, making it more attractive for routine characterization. As both SPT and AUC independently provide aspect ratio information for disk and rod like particles, their combination can allow for the determination of particle dimensions in the case of a highly monodisperse preparation. For example, a sample of SDS conjugated SWCNT was found to have to hydrodynamic radius and length of 2.8 nm and 308 nm respectively.

Single-particle tracking for the routine characterization of polydisperse nanoparticle solutions

256th National Meeting (2018)

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