Assessments of NTA

Nanoscale materials, in the form of nanoparticulates, play an important and growing role across a range of different applications and industries who seek to exploit the significantly enhanced properties exhibited by such materials when divided to ultrafine dimensions (e.g. greatly increased surface area, number concentration, etc.). The overall properties and stability of many manufactured products often depends upon the ability to repeatedly produce particle populations with fine tolerances, without the presence of contaminants or aggregates. The concentration of particles within a suspension is another factor that may have an effect upon the desired outcome of a product. It is clear then that there is a real need to characterize a variety of different properties when analyzing nanoparticles in order to fully understand the relationship between the formulation and the overall bulk characteristics of the materials (Fedotov, 2011). Similarly, Paterson et al. (2011) have overviewed the requirement for quantified nanoparticle concentrations in environmental media in order to appropriately assess the risks to biological species due to potential nanoparticle exposure. In response to the recent European Commission definition of the term 'nanomaterial' in which a material is deemed to be such if it contains over 50% by number of particles with at least one dimension below 100nm, Linsinger et al. (2012) have reviewed the requirements on measurements for the implementation of the definition. Finally, Brown et al. (2013) have also recently highlighted current particle size metrology challenges faced by the chemical industry due to the move towards classifying industrial materials by their number content of sub–100-nm particles which could have broad implications for the development of sustainable nanotechnologies. They discuss advancing nanoobject concentration measurement metrology as a path ahead to a best practice framework.