The School of Chemical Engineering at the University of Birmingham is using
nanoparticle characterisation systems to study viruses and catalyst nanoparticles.
Comparison of techniques (sample of a hematite dispersion): a) NanoSight data showing three main peaks; b) DLS data for same sample, single peak; c) TEM image showing singlets, doublets, triplets and other aggregations; d) comparison of TEM results, NanoSight results and off lattice model. Figure courtesy of Nanotechnology 20 (2009) 275701(4pp)
Working in the group of Professor Kevin Kendall, Marie-Curie Research Fellow,
Dr Shangfeng Du, says "it's a very good tool for us to characterise the molecular
adhesion and fracture, and interaction between particles in the research areas
of catalysts and the biosciences."
Dr Du’s research concentrates on the catalyst nanoparticles for fuel
cells. An important emphasis of this effort is on the synthesis of nanoparticle
catalysts of Pt, Ni and base metals, especially to produce new degrees of aggregation
in their structure, characterising the nanoparticles to define the new structures,
compositions and processes.
For catalyst characterisation, knowing the particle size based on number is
very important as it is directly linked to the catalytic performance. By knowing
the size distribution of the particles in suspension, information on the molecular
adhesion such as the singlet, doublet, triplet and larger aggregations can be
obtained. This is very useful in the understanding of the processing of dispersions.
Before finding out about NanoSight, the group mainly used electron microscopy
(TEM and SEM) and dynamic light scattering (DLS) to measure particle size and
aggregation. The main benefit of NanoSight’s nanoparticle tracking analysis
(NTA) is that it tracks particles individually making it possible to analyse
small aggregations like doublets or triplets which were not seen by DLS. Moreover,
it can be used to analyse the sample using a very low concentration which is
very difficult by DLS or electron microscopy techniques.
The success at Birmingham has led Dr Du to anticipate more achievements in
this area. This work has already been expanded into the measurement of molecular
interactions between nanoparticles and could have significant application use
in a number of fields. One such area is on-line calibration of virus number
concentrations which may be studied simultaneously with the interactions of
viruses with polymer surfaces.