Tubular and Planar Approaches to Separations (TAPAS)

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With support from the Chemical Measurement & Imaging (CMI) Program in the Division of Chemistry, Professor Purnendu K. (Sandy) Dasgupta and his students at the University of Texas at Arlington are working to improve the performance and portability of a family of important instruments known as chromatographs. These instruments are widely used for separating the constituents of complex mixtures, enabling further analysis of the separated components. The underlying science of chromatography is critical for applications such as assuring the purity of reagents used in the semiconductor industry; environmental analysis (including monitoring reactive pollutants that cannot survive a long trip to the lab); monitoring water disinfection byproducts; manufacturing pharmaceuticals; and monitoring food safety. The Dasgupta group is working to make such instruments easily field-portable (small, lightweight, low-power, and low-cost) without compromising their separation capabilities. The aim is on-site measurement in such contexts as a physician’s office or patient's bedside; industrial troubleshooting; and water-monitoring in submarines and even in the international space station. Through involvement of students ranging from junior- and senior-level high school interns through postdoctoral fellows, Professor Dasgupta is also addressing the high demand for people trained to use these techniques. As he develops new instruments and techniques, he is incorporating them into laboratory curricula and working with instrument-makers for commercialization.The Dasgupta group is using moldable ion-exchange polymers developed in the previous NSF-funded project to make ion transport-driven nonmechanical nL/min - uL/min pumps and molded microchannels to provide ultra-miniature suppressors and eluent generators. Open-channel columns with helical and 2D/3D serpentine geometries are being systematically investigated for their separations capabilities. These columns can be fabricated by 3D printing and near-IR laser machining, making them inexpensive and amenable to mass production. The team is exploring direct photothermal and multireflection absorption measurements for sensitive detection, as well as computational techniques to reduce dispersion. Finally, they are exploring the use of porous tubes (where radial flow is induced by evaporation) and pressure-driven axial flow in the presence of a transverse, time-dependent, electric field as approaches to achieving the high separation efficiencies characteristic of microchannels while operating at higher flow rates, so that extra-column dispersion requirements are lessened.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.