A General Nanoparticle Conversion Pathway to High Entropy Alloy and Intermetallic Nanoparticles and Polyelemental Heterostructures

With the support of the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Professor Skrabalak of Indiana University and her team will investigate how to precisely design and produce complex nanoparticles made from four or more elements. These materials, known as polyelemental nanoparticles, could offer unique properties that do not exist in simpler materials made of fewer elements. Such properties include improved strength, stability, and reactivity. This research could pave the way for new materials used in energy technologies, industrial catalysis, and next-generation electronics. Moreover, this project will provide immersive research experiences and professional development for graduate and undergraduate students, with a focus on scientific communication and mentoring. Public engagement activities—including interactive nanoscience exhibits and community events, will be used to enhance the visibility and accessibility of nanoscience while helping to prepare a well-equipped STEM workforce. This research will aim to establish general design principles for synthesizing high entropy alloy (HEA) nanoparticles, high entropy intermetallic (HEI) nanoparticles, and polyelemental heterostructures via thermal conversion of polyelemental core@shell nanoparticles. HEA nanoparticles—single-phase solid solutions composed of five or more elements in near-equal ratios—are expected to exhibit enhanced mechanical, chemical, and catalytic properties due to their high entropy of mixing. HEI nanoparticles, with their partially ordered multi-elemental structures, may offer distinct bonding environments that improve stability and performance in catalytic applications. The proposed strategy will involve the seed-mediated synthesis of core@shell nanoparticles followed by annealing to drive interdiffusion and phase transformation. Through three specific aims, Professor Skrabalak's team will investigate how nanoparticle composition, structure, and interactions with support materials influence the formation of HEAs, HEIs, or heterostructures. By integrating experimental studies with computational modeling, the research is expected to yield a broadly applicable framework for the rational design of compositionally complex nanoparticles. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.