Fundamentals of Interfacial Physics in Magnetic Colloid Stability by Marco Giardiello, UoL

In this nexMPI Training School lecture, Dr. Marco Giardiello from the University of Liverpool, UK, introduces the fundamental principles of interfacial physics governing the stability of magnetic colloidal systems. The presentation explores how particle size, surface area, and interfacial energy influence the behavior and aggregation of magnetic nanoparticles, with particular emphasis on superparamagnetic iron oxide nanoparticles (SPIONs). Key topics include DLVO theory, the balance between attractive and repulsive interactions, and the mechanisms of electrostatic and steric stabilization using surfactants and polymer coatings. The lecture also examines the effects of ionic strength, electric double-layer interactions, and polymer layer thickness on colloidal stability. Finally, it introduces dynamic light scattering (DLS) as a technique for characterizing colloidal systems, highlighting the importance of surface properties and hydrodynamic particle size in understanding and maintaining stable magnetic nanoparticle dispersions.