The rheological response of soft materials is governed by the structural dynamics at the microscale, driven by fluid-particle and particle-particle interactions. Notably, a single material can exhibit puzzling non-monotonic mechanical behaviors, determined by interactions of different natures dominating at different strain and strain-rate regimes. In this context, mastering the engineering of colloidal interactions opens the door to designing soft materials with diverse functionalities, such as bulletproof vests, advanced 3D printing materials, and tissue engineering. Further, tuning the interactions of particles through the application of external fields enables the design of field-activated materials, allowing for precise control over mechanical responses, a promising approach for soft robotics and artificial muscles.
My research focuses on understanding the dynamics of suspended particles in low-Reynolds-number regimes, with a special interest in hydrodynamic phenomena, the rheology of complex interfaces, and interactions with external fields. Many problems within these topics are essential for both practical and theoretical advancements across various fields, from the oil industry to biomedical applications. The nonlinearity, complex geometries, stochasticity, and moving boundaries characteristic of these problems preclude the development of analytical solutions, making numerical methods particularly valuable. Much of my research is dedicated to implementing different numerical techniques to capture the coupling between hydrodynamics and external fields. But I am also committed to couple experimental investigations to make the research more solid.
Prior and Current Work
During my master’s, I conducted numerical investigations on the shear rheology of a single ferrofluid droplet under the influence of magnetic fields. My simulations demonstrated how magnetic fields could either induce or hinder droplet break-up due to shear flow, as well as increase or decrease shear viscosity in the system, depending on the intensity and direction of the applied field. These findings are of great interest for the development of advanced materials as well as the refined control over emulsion droplet size distribution.
As a PhD student, I worked on the settling dynamics of colloidal chains, the hierarchical assembly of magnetic colloids, the dynamics of magnetic filaments under time-varying magnetic fields, and the magnetic relaxation of superparamagnetic colloids. The scientific robustness of these investigations was conferred by coupling experimental and numerical investigations. Key contributions include the development of an experimental methodology to measure the magnetic relaxation time of paramagnetic colloids, the description of the settling dynamics of semi-flexible Brownian filaments in the view of fluid-structure coupling, and the discovery of hydrodynamically induced knotting in semi-flexible polymers driven by strong magnetic fields.
Currently, I hold a Postdoctoral Fellowship position at the Institute for Soft Matter Synthesis and Metrology (ISMSM) at Georgetown University (GU), where I work as an independent researcher and coordinate collaborative projects between ISMSM and the National Institute of Standards and Technology (NIST). In this role, I lead a project focused on understanding the role of hydrodynamics in the rheology of semi-dilute colloidal rod suspensions at high-shear rates. To address this problem, I developed a Brownian dynamics code that accounts for long-range hydrodynamic interactions between rods, providing deeper insight into their dynamics at the microscale and how this influences the bulk response of the complex fluid. This work is of significant practical relevance, as the high-shear rates investigated are comparable to those commonly encountered in industrial processes such as extrusion, coating, and mixing.
Related Oral and/or Poster Presentations
Brownian Dynamics Simulations of Filaments: Settling Dynamics of Semi-Flexible Polymers and Shear Rheology of Colloidal Rods - ID: 717169
Numerical Investigation of the Role of Hydrodynamic Interactions in the Shear Rheology of Colloidal Rod Suspensions Via Brownian Dynamics Simulations - ID: 712577
Bridging Colloidal Sciences to Functional Materials - ID: 716031