All gone to Argonne

Posted: November 14, 2022

Soenke Seifert, Barbara Wyslouzil, Xian Wu, Jeff Chalmers at Argonne

Last July, faculty members Barbara Wyslouzil, Jeffrey Chalmers, and graduate student Xian Wu from the Chalmers Lab visited the Argonne National Laboratory in Lemont, IL.

Wyslouzil, Chalmers, and Wu took the trip to better understand how 5 - 15 nm nanoparticles respond in the presence of a magnetic field gradient.

They conducted Small Angle X-ray Scattering (SAXS) experiments because these give much better insight into whether particles are agglomerating, or forming structures or not, or if they remain as isolated entities.

The experiments gave Chalmers and Wu quantitative concentration measurements that are not possible with visual observations made in the Ohio State laboratories.

The group used the computers at Argonne to control the X-ray beam, collect the data, and do some of the analysis. They used the 12-ID-B beam line at Argonne's Advanced Photon Source facility. Working with them is beamline scientist Soenke Seifert.

Xian Wu reports, "We investigated the magnetic separation of 5, 15 and 30nm superparamagnetic iron oxide nanoparticles (SPIONs) by applying external magnetic fields and gradients (provided by quadrupole magnetic sorters, QMS, and Cell Tracking Velocimetry, CTV magnet). Our preliminary results show that there’s concentration gradient of particle suspensions after applying magnetic field. The image recording setup in OSU is not good enough for accurate analysis.

"In order to better understand the separation mechanism, we used Small Angle X-ray Scattering using 12-ID-B beamline at Advanced Photon Source at Argonne National Laboratory. SAXS is to examined the possible aggregation behavior of SPIONs in solution. X-rays can provide the correct wavelength radiation to probe the structure of the nanoparticle clusters.

"We conducted in-situ SAXS experiments by placing the SPIONs within the magnet separators in the beamline for different lengths of time. 9 position resolved measurements were made. Below is the SAXS patterns of 30nm SPIONs exposed to CTV magnet for 30mins. 3D crystalline superstructure of magnetic particles was formed, indicating the self-assembly behavior."