Clustering and Dynamics of Magnetic Nanoparticle Suspensions

We have developed magneto-optical relaxation measurements (MORFF) as an instrumentation technique to investigate clustering and long-term stability of superparamagnetic nanoparticles. In this work, we demonstrate the use of MORFF and validate our results by comparing it with dynamic light scattering (DLS) and X-ray diffraction analysis (XRD). By changing functionalizations on the nanoparticles, the aggregation and fragmentation can be changed and we show that our technique is sensitive enough to measure mean size changes down to 10 nm changes on 100–200 nm sized nanoparticles. DLS data has been compared with X-ray Diffraction and magneto-optical relaxation data to measure the long-term stability of the solutions.