Year-end Sale % OFF 
Abstract
This paper presents the first worldwide inter-laboratory comparison of small-angle X-ray scattering (SAXS) for nanoparticle sizing. The measurands in this comparison are the mean particle radius, the width of the size distribution and the particle concentration. The investigated sample consists of dispersed silver nanoparticles, surrounded by a stabilizing polymeric shell of poly(acrylic acid). The silver cores dominate the X-ray scattering pattern, leading to the determination of their radius size distribution using (i) the generalized indirect Fourier transformation method, (ii) classical model fitting using SASfit and (iii) a Monte Carlo fitting approach using McSAS. The application of these three methods to the collected data sets from the various laboratories produces consistent mean number- and volume-weighted core radii of Rn = 2.76 (6) nm and Rv = 3.20 (4) nm, respectively. The corresponding widths of the lognormal radius distribution of the particles were σn = 0.65 (1) nm and σv = 0.71 (1) nm. The particle concentration determined using this method was 3.0 (4) g l-1 or 4.2 (7) × 10-6 mol l-1. These results are affected slightly by the choice of data evaluation procedure, but not by the instruments: the participating laboratories at synchrotron SAXS beamlines, commercial and in-house-designed instruments were all able to provide highly consistent data. This demonstrates that SAXS is a suitable method for revealing particle size distributions in the sub-20 nm region (at minimum), out of reach for most other analytical methods.
Highlights
Demonstrating that a given technique is truly able to reliably determine the size distribution and quantify the number of nano-objects is of great importance
A few such round robin experiments exist for the analytical methods used in nanotechnology, most notably for single-particle inductively coupled plasma mass spectrometry (ICP-MS) (Linsinger et al, 2014; Montoro Bustos et al, 2015) and transmission electron microscopy (Rice et al, 2013)
Volume- and number-weighted radii distribution derived from data set number 2, shown as blue and red lines, respectively. (b) Number-weighted radii, Rn,indirect Fourier transformation (IFT), and widths of the size distribution, n,IFT, as a function of the data set number
Summary
Demonstrating that a given technique is truly able to reliably determine the size distribution and quantify the number of nano-objects is of great importance Such a demonstration can be done using an inter-laboratory or ‘round robin’ comparison, comparing results inferred from measurements of identical samples on different instruments. A few such round robin experiments exist for the analytical methods used in nanotechnology, most notably for single-particle inductively coupled plasma mass spectrometry (ICP-MS) (Linsinger et al, 2014; Montoro Bustos et al, 2015) and transmission electron microscopy (Rice et al, 2013). Results from SAXS have repeatedly been demonstrated to agree well with findings from electron microscopy (Borchert et al, 2005; Rosalie & Pauw, 2014), and comparisons between the results of two or three SAXS instruments suggest that the inter-instrument reproducibility could be satisfactory
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
