Determination of the size distribution of non-spherical nanoparticles by electric birefringence-based methods

Abstract

The in situ determination of the size distribution of dispersed non-spherical nanoparticles is an essential characterization tool for the investigation and use of colloidal suspensions. In this work, we test a size characterization method based on the measurement of the transient behaviour of the birefringence induced in the dispersions by pulsed electric fields. The specific shape of such relaxations depends on the distribution of the rotational diffusion coefficient of the suspended particles. We analyse the measured transient birefringence with three approaches: the stretched-exponential, Watson-Jennings, and multi-exponential methods. These are applied to six different types of rod-like and planar particles: PTFE rods, goethite needles, single- and double-walled carbon nanotubes, sodium montmorillonite particles and gibbsite platelets. The results are compared to electron microscopy and dynamic light scattering measurements. The methods here considered provide good or excellent results in all cases, proving that the analysis of the transient birefringence is a powerful tool to obtain complete size distributions of non-spherical particles in suspension.

Functionalized, Vertically Super-Aligned Multiwalled Carbon Nanotubes for Potential Biomedical Applications

“…Dynamic light scattering spectroscopy provides information on the size distribution of nanomaterials [15]. This technique is most suitable for the determination of diameter of spherical particles, but it is still applicable for measuring hydrodynamic diameters of nanotubes [16]. Zeta potential is based on electrophoretic mobility for charge determination on the particles.…”

Towards Standards for Light Scattering Studies of Proteins Stability and Nanoparticle-Protein Interactions

“…Thus, we apply also the CORENN algorithm, capable to analyse polydisperse samples; an example of size distributions at 0.005 mg/ml is shown Figure 1b. For the nanorods two main peaks are distinguished: the peak at large radius, RH,T, can be assigned to DT, and the one at short radius, RH,R, to DR [11]. We note that for common non-spherical particles, rotational motion occurs in a very fast time scale, such that they are not detected by DLS.…”

“…We note that for common non-spherical particles, rotational motion occurs in a very fast time scale, such that they are not detected by DLS. Au NRs, however, present birefringence [11], which renders their DR visible as a peak at small RH. The y-axis of Figure 1b is chosen as the intensity (arbitrary units) of the distribution multiplied by the RH, otherwise the intensity of the rotational peak significantly dominates over the translational one.…”

Plasma‐assisted synthesis and deposition of molybdenum oxide nanoparticles on polyethylene terephthalate for photocatalytic degradation of rhodamine B

“…It can be assumed that the hydrodynamic diameter of particles can be comparable with the maximum Feret diameter for nonspherical nanoparticles. [52] The ζ potential of nanoparticles is an important parameter affecting the stability of nanoparticles to a great extent. For the obtained nanoparticles, the value of ζ potential is about −30 mV.…”