NSF’s ChemMatCARS: A Synchrotron X-ray National User Facility for Molecular Science at the Advanced Photon Source

The Division of Chemistry and the Division of Materials Research in the Mathematical and Physical Sciences Directorate, along with the Division of Chemical, Bioengineering, Environmental, and Transport Systems in the Engineering Directorate provide continuing support to NSF's ChemMatCARS. This is a national user facility for frontier research in chemistry, materials science, biology, and engineering, employing synchrotron X-rays at the Advanced Photon Source, Argonne National Laboratory.

Experimental facilities at NSF's ChemMatCARS serve a broad national and international community of scientists providing state-of-the-art capabilities including some not found anywhere else in the world. Research activities address vital societal issues, including the development of new energy sources, biomolecular materials inspired by biological processes, studies of biomembrane interactions to understand the rules of life, environmental remediation and chemical separations processes, and new materials and catalysts important for a wide range of industries.

The facility serves as a training ground for researchers at all levels and carries out numerous activities to develop and diversify the future STEM workforce. These include specialized education, training, and career development of students, postdoctoral scholars, and faculty in forefront synchrotron X-ray studies in molecular science, as well as programs designed to address the goal of broadening participation in STEM activities.

This user facility provides a unique high brilliance X-ray resource for the study of advanced small-molecule crystallography, liquid surface and interface scattering, and anomalous small and wide-angle X-ray scattering. Advanced instrumentation at NSF's ChemMatCARS enables forefront research of ordered and disordered solids, complex fluids, and soft interfaces on the atomic, molecular, and mesoscopic length scales over a range of time scales from nanoseconds to minutes.

Users of NSF's ChemMatCARS take advantage of its unique capabilities to address a wide variety of scientific problems. The many capabilities in advanced crystallography include the structural resolution of excited state and highly reactive species with photo-crystallography. Site-specific measurements can distinguish the same-site occupancy of similar atomic number elements, as well as relative oxidation levels of the same element at crystallographically distinct sites.

Initiatives in structural dynamics, including a frontier effort in small molecule serial crystallography, will investigate systems undergoing reversible and irreversible chemical transformations. Molecular-scale structural studies of liquid interfaces using X-rays advance the synthesis of nano- and 2D materials for catalysis and energy applications, reveal the interfacial separation of critical minerals, and explore the underlying structure of sea surface microlayers and organic thin film coatings.

Lipid bilayers are utilized as model systems of biomembrane structure and dynamics, protein-lipid interactions, and nonequilibrium processes. A recently commissioned capability in X-ray absorption spectroscopy can transform our understanding of elemental speciation and oxidation at liquid interfaces. A frontier initiative will probe elemental and structural heterogeneities at liquid interfaces on small length scales.

Anomalous small and wide-angle X-ray scattering (ASWAXS) probes element-specific metal ion distributions in disordered materials to investigate metal interactions in supramolecular chemistry, metal ion interactions in solution, and elemental distributions in nanomaterials with sub-nanometer resolution.

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.