Chemical Dynamics Group
The Chemical Dynamics Group (CDG) develops, implements, and deploys state-of-the-art spectroscopy and microscopy instruments designed to probe temporal and chemical changes in complex reactive systems and extreme environments. These experimental techniques provide unique insight into the fundamental chemistry that enables important technologies such as the separation of critical materials, quantum technologies, and non-equilibrium matter. This insight has broad applicability to research across ORNL that addresses the nation’s most pressing energy challenges. CDG supports efforts to measure and understand the chemical mechanistic events underlying transient phenomena and stimuli responsive matter that is central to the development of next-generation energy efficient technologies.
The group specializes in the development and use of experimental techniques designed to measure molecular characteristics in the context of ultrafast reaction dynamics and phenomenological kinetics as they relate to the mechanisms broadly underlying chemical transformations and energy science. Through these experimental approaches, CDG aims to provide new understanding into the temporal and spatial evolution of chemical reactions through optical, magnetic, and electrochemical spectroscopies and microscopies. Examples of scientific problems actively investigated by the group include non-equilibrium separations of rare-earth elements and anions at liquid-liquid interfaces, transient photochemically generated pH gradients in bulk and interfacial environments for efficient chemical conversion, and quantum-enabled imaging modalities for low-light imaging of living plant-microbe biosystems.
CDG has access to a variety of experimental capabilities including vibrational sum frequency generation spectrometers, transient absorption spectroscopy/microscopy setups, coherent Raman tools, entangled photon spectroscopy, and nonlinear light scattering that are tailored to address specific scientific problems. These capabilities tap into ORNL’s breadth of scientific research. Experimental approaches that leverage unique capabilities in nonlinear optics to probe complex systems and interfaces. Techniques such as vibrational sum frequency generation have been adapted to probe buried liquid-liquid interfaces far from equilibrium. Current work is extending these surface-specific probes to nanoscale interfaces by way of scattering techniques and ultrafast pump-probe measurements. Synergy with neutron and X-ray beamlines and these surface-specific optical approaches provide a way to understand coupled structural and chemical changes to interfaces during a chemical reaction that is otherwise inaccessible. Similarly, new approaches using entangled light are also being developed with applications in biological imaging and controlling chemical reactions. These approaches hold promise to enable ultra-low light level imaging and access to chemical reaction pathways inaccessible to classical light.
Active Research Projects
- Solvent extraction chemistry and transport at buried liquid/liquid interfaces
- Squeezed-light microscopy for imaging living systems
- Photoacid initiated chemical conversion and dynamics
- Microbe interactions at abiotic interfaces
- Non-equilibrium energy transfer and dynamics in chemical conversions
- Critical material recovery from complex ores
- Entangled light microscopy to image complex biosystems
- Metastability in biomimetic membranes
- Transient phenomena in mechanochemical conversions
- Optical gating of ionic transport in polymer electrolytes