Multiscale Modeling of Chiral Self-assemblies of Superparamagnetic Nanoparticles

University Of Illinois At Chicago, Chicago IL

Investigators

Abstract

NON-TECHNICAL SUMMARY This award supports computational and theoretical research and education aimed at understanding cooperative mechanisms by which magnetic materials self-assemble from nanoscale colloidal components with multiple complex interactions and in the presence of magnetic, electric, and optical fields. Concise characterization and description of conditions underlying the stabilization of a rich spectrum of self-assembled materials will provide information necessary for their reproducible preparation. Dramatic progress in the area of materials formed by self-assembled nanoscale components can proceed only through a solid understanding of all underlying principles and microscopic phenomena. The research involves developing and applying computational tools for modeling of self-assembled materials, which will be shared with the broader computational materials science community. Activities associated with this research will provide rich educational experiences for graduate and undergraduate students in advanced materials theory and modeling techniques. Through collaboration with experimentalists, this research will iteratively proceed towards a deep understanding of materials properties. In this integrated experimental and computational approach, the students will gain the necessary skills to design materials and technologies aiming at development of novel devices based on these materials. TECHNICAL SUMMARY This award supports computational and theoretical research and education of magnetic materials formed by self-assembled superparamagnetic nanoparticles. The research necessitates development of multiscale modeling tools in the PI's group, in particular, efficient Monte Carlo codes able to describe large scale systems of interacting nanoparticles, where cooperative forces acting between the constituents will be parametrized by analytical calculations using known laws, atomistic molecular dynamics simulations, and estimates of coupling strengths present in the studied systems under dynamical conditions formed during the self-assembly. These studies will focus on clarifying the roles played during the self-assembly by forces acting between the nanoparticles at different length scales, the effects of choosing different materials, sizes and shapes of the nanoparticles, their ligands and solvents, overall charging, and external magnetic, electric, and optical fields. This modeling approach should reveal the spatial and magnetic structures of nanoparticle chains, ribbons, stripes, clusters, and helices, and the origins of their arrangements observed in experiments. Through development of novel modeling methods, the project will advance the knowledge of experimentally prepared materials based on self-assembled nanoscale components with complex interactions leading to numerous possible final structures tunable by external fields. These materials will form a rich platform for future generations of devices with numerous applications. Activities associated with this research will provide rich educational experiences for graduate and undergraduate students in advanced materials theory and modeling techniques. Through collaboration with experimentalists, this research will iteratively proceed towards a deep understanding of materials properties.