SAXS for the determination of the size distribution of nanoparticles: Application in catalysis
- The open source software packages SASfit1 and McSAS2 are widely used to determine the size distribution of nanoparticles. SASfit is based on classical curve fitting. The type of size distribution needs to be provided as constraint for analysis. Very often the lognormal size distribution is useful as shown for the characterization of single- and multimodal magnetic iron oxide particles. The use of SASfit is part of efforts to standardize analyzing methods for magnetic nanoparticles within the EU project NanoMag (www.nanomag-project.eu). In contrast to SASfit, it is not necessary to provide the type of size distribution when using the program McSAS. Both programs provide tools that allow the user to estimate uncertainties of the derived size distributions. Such is helpful in the development of nanoscale reference materials for environmental, health and safety measurements. As an example, a detailed study on using SAXS in the characterization of ultra-small-silver nanoparticles isThe open source software packages SASfit1 and McSAS2 are widely used to determine the size distribution of nanoparticles. SASfit is based on classical curve fitting. The type of size distribution needs to be provided as constraint for analysis. Very often the lognormal size distribution is useful as shown for the characterization of single- and multimodal magnetic iron oxide particles. The use of SASfit is part of efforts to standardize analyzing methods for magnetic nanoparticles within the EU project NanoMag (www.nanomag-project.eu). In contrast to SASfit, it is not necessary to provide the type of size distribution when using the program McSAS. Both programs provide tools that allow the user to estimate uncertainties of the derived size distributions. Such is helpful in the development of nanoscale reference materials for environmental, health and safety measurements. As an example, a detailed study on using SAXS in the characterization of ultra-small-silver nanoparticles is presented. These particles are useful in the catalytic reduction of 4-nitrophenol and display an adjustable activity (see Figure).
Figure. Core-shell silver nanoparticles catalyze the reduction of 4-nitrophenol and display an increasing catalytic activity when stabilized with different ligands in the line bovine serum albumin (BSA), glutathione (GSH) and polyacrylic acid (PAA).5…