By Dr Ananya Mandal, MD
To understand the potential of nanoparticles, a deeper knowledge of their synthesis and applications is needed. Characterization is done by using a variety of different techniques, mainly drawn from materials science.
Traditional characterization of a particle
Traditional approach to characterizing a particle (not necessarily nanoparticles) includes:
- Molecular structure or composition
- Melting point
- Boiling point
- Vapor pressure
- Water proportion and octanol
- Soil proportion and water part.
Nanoparticle characterization parmeters include:
- Surface area and porosity
- Particle size distribution
- Hydrated surface analysis
- Zeta potential
- Adsorption potential
- Shape and size of interactive surface
Understanding nanoparticle characterization parameters
There are several techniques used to understand these characterization parameters in nanoparticles. They include:
- electron microscopy including TEM and SEM
- atomic force microscopy (AFM)
- dynamic light scattering (DLS)
- x-ray photoelectron spectroscopy (XPS)
- powder X-ray diffraction (XRD)
- Fourier transform infrared spectroscopy (FTIR)
- matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF)
- ultraviolet-visible spectroscopy
- dual polarisation interferometry
- nuclear magnetic resonance (NMR)
- Nanoparticle tracking analysis (NTA) for tracking of the Brownian motion
Characterization technologies for manufactured Nanoparticles
Developments of measurement and calibration technologies are in practice for particle size, distribution and concentration of manufactured nanoparticles from 1nm to 100nm using practical methods.
Technologies statistically analyse the shape and size of manufactured nanoparticles such as carbon nanotubes, fullerenes and titinium oxides in tissue samples from electron microscope images. In addition, some methods are used to ﬁlter capture efﬁciency of manufactured nanoparticles in air and some calibration technologies have been developed to eliminate errors due to the shape and material of manufactured Nanoparticles.
Preparation and publication of a manual is important to standardize all of the technologies for characterization of Nanoparticles.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)