The diffusive dynamics of 100 nm to 400 nm diameter polystyrene nanoparticles dispersed in water were studied using brightfield and fluorescence based differential dynamic microscopy (DDM) and compared to those obtained from dynamic light scattering. The relaxation times measured with brightfield and fluorescence DDM over a broad range of concentration of nanoparticles (10 -6 ≤ φ ≤ 10-3) and scattering vectors (0.5 μm-1 < q < 10 μm-1) are in excellent agreement with each other and extrapolate quantitatively to those obtained from DLS measurements. The diffusion coefficients extracted from the q-dependent relaxation times using all three methods are independent of the nanoparticle concentration. © 2012 The Royal Society of Chemistry.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-C1-018-02
Acknowledgements: We thank Prof. J. Rimer for the use of the DLS instrumentation. This publication is based on the work supported in part by award no. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.