Lynda Soderholm and Aurora Clark (WSU) are organizing a workshop on chemical separations during 2019 APS/CNM Users Meeting. The full-day workshop will be on May 7, 2019. Attending the workshop requires a registiration to APS/CNM Users Meeting (May 6-8).
Chemical-separations researchers represent an untapped user group for synchrotron facilities. X-ray photons offer a variety of opportunities for the chemical separations community, who are struggling with materials performance issues as they look to develop better, more efficient ways to refine natural resources such as petroleum, purify specialty chemicals from rare-earth ores, or deal with effective radioactive-waste disposal. To date researchers in this field have concentrated largely on in-house resources, despite the fact that their problems are on the forefront of some of the most interesting, cutting-edge challenges under study today. For example, most of their materials can be classified as soft matter, including structured solutions, membranes, polymers, and bio-inspired organics. Many systems are amorphous, with hierarchical structuring playing a largely unexplored role in processes of interest.
The opportunity for a mutually beneficial collaboration between chemical-separations researchers and synchrotron-facility personnel lays in answering fundamental questions of structure-function relationships in complex, evolving soft-matter systems. From a separations perspective, synchrotrons can provide information about structuring from local to mesoscopic length scales, providing here-to-fore unavailable insights into the free-energy drivers for these processes. Spectroscopic, scattering, and imaging studies such as those available at the APS would provide new windows into how these separations systems work. The impact of this work is further enhanced when combined with advanced molecular simulations methods that provide a bridge between the molecular level structure and ensemble average measured data. For example, very recent XPCS studies at the APS on the liquid-liquid phase transitions known to impede separations efficacy are resolving questions in favor of a micellar model over a simple biphasic model, thus revealing promising new avenues to resolve this problem. From the APS perspective, SAXS experiments can be used to quantify the structural changes occurring as the phase transition is approached by varying temperature. Dynamics studies reveal aggregate
fluctuations on the order of 20 microseconds, just at the limit of current APS capabilities. These studies are informing APS efforts to prepare for the upgrade by providing opportunities to quantify issues ranging from detector-speeds to big-data analysis scenarios.
This workshop will bring together leaders in the fields of separation sciences, modeling and simulation, and machine learning with synchrotron experts in spectroscopy, scattering, and imaging to discuss mutual interests and set the groundwork for collaborative efforts that would benefit all communities involved. Expected outcomes include a roadmap for new ways to integrate these techniques to increase the breadth, applicability, and impact of APS experiments to a diverse and growing chemical-separations user base. Separations is acknowledged as an important impact area within the national research landscape, as demonstrated by the ongoing National Academy of Sciences committee study on A Research Agenda for a New Era of Separations Science.