Dr. Isaac Torres-Díaz, a researcher at The University of Alabama in Huntsville (UAH), has won a $588,000 National Science Foundation (NSF) CAREER Award to support research into magnetic nanoparticles, which can be manipulated using magnetic fields. These particles consist of a magnetic material, often iron, nickel and cobalt, combined with a chemical component, for a wide range of applications, such as sensors and nanobots that can be inserted into the blood to execute non-invasive treatments at cellular scales or support hyperthermia therapy in the treatment of cancer.
With magnetic hyperthermia for medical treatments, the potential enhanced heating effect is caused by the orientation of magnetic particles and their interactions. Overall, the award can advance the fundamental understanding of hydrodynamics and nanotechnology.
Torres-Díaz’s work also benefits magneto-rheology – the branch of physics dealing with the deformation and flow of matter – due to the variable polarization response based on the size and shape of the magnetic particles. These advances could lead to “smart” fluids that change viscosity in the presence of a magnetic field, of significant commercial interest for engineering applications such as car shock absorbers and aerospace hydraulic dampers that convert the kinetic energy of moving parts into thermal energy. The innovations offer potential boons for drug delivery advancements as well for transporting pharmaceutical compounds to a target site to achieve a desired therapeutic effect.
The Faculty Early Career Development CAREER Program offers the NSF's most prestigious awards in support of early-career faculty. The five-year grant will address one of the main challenges in colloid science, which is to establish the connections between interacting particles with different shapes and their arrangement under the influence of a magnetic field. Colloid science is an interdisciplinary blend of chemistry, physics, nanoscience and other fields that deals with colloids, which are homogeneous substances consisting of large molecules or ultramicroscopic particles of one substance dispersed through a second substance.
“A part of a researcher's activities is to find and define problems relevant to society,” says Torres-Díaz, an assistant professor of Chemical and Materials Engineering at UAH, a part of The University of Alabama System. “My passion for magnetic nanoparticles and my long experience studying them from theoretical and experimental perspectives have driven me to define this as a research topic. One of the main challenges is to quantify their interactions as a function of position and orientation.”
The main goal is to gain insights that help realize the potential of anisotropic colloids. Unlike isotropic colloids, such as uniform spheres which show the same properties in all directions, anisotropic particles, shapes such as rods, ellipsoids and cubes, are non-uniform in their shape and show different properties in different directions.
“I combined my mechanical and chemical engineering background to tackle a fundamental problem of interacting anisotropic particles that can potentially impact different applications,” Torres-Díaz says.
The research is especially important to the development of “tunable materials,” where certain materials have a polarization that can be reversed by the application of an external magnetic field. The work impacts polarized surfaces, such as when a chemical film is applied to a transparent plastic or glass surface to filter the light that is allowed to pass through.
