Image Credits: GiroScience/shutterstock.com
In many industries and applications, nanomaterials in the form of nanoparticulates play a key role due to their unique properties exhibited when divided into ultra-fine dimensions (e.g. greatly increased surface area, number concentration, etc.).
In a large number of manufactured products, their stability and overall characteristics mostly rely on their ability to constantly create particle populations with very fine tolerances, without the presence of any aggregates or contaminants. Yet another factor that could impact the outcome of end products is the particle concentration within a suspension. This shows that when nanoparticles are being studied, it is important to define a wide range of properties to gain a better insight into the link between the overall bulk properties and formulation of the materials (Fedotov, 2011).
In a similar manner, the need for measured nanoparticle concentrations in environmental media was reviewed by Paterson et al. in 2011 to properly assess the hazards posed to biological species due to exposure to nanoparticles. The European Commission defined that a material is considered to be a nanomaterial if it includes more than 50% of particles with at least a single dimension of less than 100 nm. In response to this new definition, Linsinger et al. (2012) assessed the measurement needs for implementing this definition.
Brown et al. (2013) emphasized the existing difficulties encountered in the chemical industry with regard to particle size metrology. These challenges are the result of redefining industrial materials by their number content of sub–100 nm particles that hold immense potential for developing nanotechnologies, which are sustainable by nature. Developing metrology for nanoobject concentration measurement was deemed to be a defining factor for a best practice framework.
Nanoparticle tracking analysis (NTA)
Nanoparticle tracking analysis (NTA) is a new method that is based on well-defined principles of sizing by determining the rate of Brownian motion of particles to provide nanoparticle Dt. From this nanoparticle Dt, it is possible to predict a spherical hydrodynamic diameter. The NTA technique uses the optical configuration, which makes it possible to concurrently track and study nanoparticles on an individual basis. Remarkably, the data that is obtained is not an intensity weighted mean as in a DLS technique, but rather a high resolution analysis of particle size distribution. This makes it possible to differentiate different types of materials via their varied refractive indices, and also to recover the concentration of particles.
This information has been sourced, reviewed and adapted from materials provided by Malvern Panalytical.
For more information on this source, please visit Malvern Panalytical.