Nanoparticle synthesis and characterization

One of the NanoSphere concepts is to build up a library of nanoparticles with relevant physic-chemical structure variations to provide a foundation for generating structure-activity relation type knowledge.

The design and synthesis of well-defined nanoparticles go hand in hand with appropriate characterization methodologies, wherefore NanoSphere aim to develop and/or critically evaluate methods (e.g. DLS, FFF, SEM, TEM, ES-SMPS and NTA) and protocols for nanomaterial characterization and analysis. Compared to conventional molecular compounds, more descriptors are needed to fully characterize a nanomaterial, which is illustrate below.

The figure illustrates relevant physico-chemical descriptors for fate and toxicity studies (from Hassellöv & Kaegi, 2009)

Synthesis of size-controlled colloidal TiO2 nanoparticles

Within NanoSphere, synthesis, characterization and determination of surface properties of nanosized TiO2 particles has been peformed.

Here we see PhD student Jenny Perez Holmberg synthesizing titanium dioxide nanoparticles of well defined size and crystallinity. By controlling the reaction conditions (e.g. reaction temperature and dialysis conditions) different particle sizes are obtained. The synthesis products are characterized with a range of techniques. Structural properties were determined by XRD and TEM, whereas size distributions were obtained by the electrospray scanning mobility particle sizer (ES-SMPS) and dynamic light scattering (DLS). These particles are used in several toxicity and environmental fate studies as case study particles.

Particle size distribution of TiO2 colloidal nanoparticles of various sizes as determined by the electrospray scanning mobility particle sizer method (adapted from Abbas et al 2011).

Z. Abbas., Holmberg, J. P., Hellström, A. K., Hagström, M., Bergenholtz, J., Hassellöv, M., Ahlberg, E. Synthesis, characterization and particle size distribution of TiO2 colloidal nanoparticles, Colloids and Surfaces A: Physicochem and Enginer. Aspects. 2011, (In Press) doi:10.1016/j.colsurfa.2011.03.064.

Unusual aggregation behavior of nanoparticles smaller than 20 nm in diameter

Dynamic light scattering measurements on particles of different sizes revealed that the diffusion coefficient of approxiametely 8 nm particles decreases as the volume fraction decreases. This is unusual behavior which is peculiar for nanoparticles of size less than 20 nm.

Holmberg, J. P., Abbas, Z., Ahlberg, E, Hassellöv, M., Bergenholtz, J., Non-linear concentration dependence of the collective diffusion coefficient of TiO2 nanoparticle, 2011, J. Phys. Chem. C (In press).

Particle tracking as a method to characaterize nanoparticles

Nanoparticle Tracking Analysis (NTA) is a quite novel method to characterize nanoparticles based on their movements in liquid (example film). Within NanoSphere, NTA has been critically evaluated and protocols have been optimized for different applications (e.g. environmental measurements, fate and effect studies)


Julian Gallego, Jani Tuoriniemi, Tobias Pallander and Martin Hassellöv. Measurements of nanoparticle number concentrations and size distributions in contrasting aquatic environments using nanoparticle tracking analysis. Environmental Chemistry, 2010, Vol 7, p. 67-81

Julian A. Gallego-Urrea, Jani Tuoriniemi, Martin Hassellöv. Applications of particle-tracking analysis to the determination of size distributions and concentrations of nanoparticles in environmental, biological and food samples. Trends in Analytical Chemistry, 2011 30 (3), p. 473-483

Contact person

Zareen Abbas

Page Manager: Robert Karlsson|Last update: 11/17/2014

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