Fast USAXS Measurements of µm-sized Particles Using a Laboratory System USAXS/SAXS/WAXS Beamline

Introduction

The properties and behavior of many materials – both natural and synthetic – rely on their structure at the nanoscale. However, such nanostructures often co-exist with larger networks (e.g., agglomerates composed from small, nano-sized building blocks).
Analyzing either only the nano- or the micrometer scale cannot provide the full structural information and does not fully characterize a sample. Materials that can be analyzed by USAXS and SAXS include (1-4):

• micro- and nanoparticles,
• catalysts,
• metals and binary alloys,
• viruses and bacteria,
• energy-storage/conversion materials, and
• highly aggregated samples.

Small-angle X-ray scattering (SAXS) is a commonly used method for the characterization of nanostructured materials due to its wide applicability and the ability to perform in situ measurements. The resolution of “classic” small-angle X-ray scattering instruments is limited to a maximum size of around 300 nm, limiting SAXS to be applied for larger, µm-sized systems. Ultra-small-angle X-ray scattering (USAXS) extends the accessible size range into the micrometer regime as it measures extremely small scattering angles. (4) With the combination of USAXS and SAXS measurements, many materials can be analyzed by resolving both the micrometer and the nanometer scale. 

Speed matters

Combined USAXS-SAXS measurements can be performed at synchrotron beamlines and laboratory SAXS instruments. With a standard Bonse-Hart module, USAXS measurements on a laboratory instrument can take several hours, mainly due to the low intensity of the collimated primary X-ray beam.

Anton Paar’s improved USAXS module for the SAXSpoint laboratory system significantly accelerates USAXS measurements by a factor of around 10 compared to the classic Bonse-Hart design. This advancement empowers researchers to obtain size information on micro- and nano-sized materials in the laboratory much faster than before.

References:

1. Hornfeck W, Nucleation and crystal growth in a suspension of charged colloidal silica spheres with bi-modal size distribution studied by time-resolved ultra-small-angle X-ray scattering, J. Chem. Phys. 141, 214906 (2014).
2. Li T, Synthesis and Advanced Characterization of Polymer–Protein Core–Shell Nanoparticles, Cata-lysts 2021, 11(6), 730
3. Reeja-Jayan B, Multiscale operando X-ray investi-gations provide insights into electro-chemo-mechanical behavior of lithium intercalation cath-odes, Applied Energy 299, 117315 (2021).
4. The SAXS Guide, 5th ed. (Anton Paar, 2023).
5. This work benefited from the use of the SasView application, originally developed under NSF award DMR-0520547. SasView contains code developed with funding from the European Union's Horizon 2020 research and innovation programme under the SINE2020 project, grant agreement No 654000. www.sasview.org