Senior Material Scientist
Pacific Northwest National Laboratory
Dr. Radha Kishan Motkuri, a senior material scientist with the PNNL Energy Processes and Materials Division. He serves as principal investigator (PI), Co-PI, and project manager in diverse range of projects in material chemistry and chemical security. He has over 20 years of experience in inorganic and material chemistry with an emphasis on nanoporous materials such as zeolites, Metal-organic frameworks (MOFs), covalent organic frameworks, mesoporous silica and heirarchical porous carbons(HPCs) for potential applications including sorption, separation, catalysis, detection and sensing. Dr. Motkuri has published more than ~90 peer-reviewed publications (e.g., in JACS, Accounts of Chemical Research, Angwandte Chemie, Nature Communications, Adv. Mater. Etc.,), eleven journal coverARTs, >2600 citations with H-index 25 (Google scholar), more than 70 presentations. Also, Dr. Motkuri has 15 international patents while seven of them are USA patents/applications. Recent success of his projects including a series of cooling technology development projects and PNNL’s 2017 R&D 100 Award winning thermal vapor-compression cooling technology. His work supports the DOE Office of Energy Efficiency and Renewable Energy (EERE), ARPA-E, Department of State’s Chemical Security Program, and PNNL’s LDRD. Dr. Motkuri organized or co-organized several sessions at American Chemical Society (ACS) meetings, including Functional Porous Materials for Sustainable Energy (253rd ACS); Porous Materials for Energy Conversion (246th ACS National Meeting), Carbon Dioxide Management (248th and 257th ACS meeting). Dr. Motkuri is an editorial board member for the prestigious inorganic and material journals: “Inorganic Chimistry (American Chemical Society)”; “Inorganic Chimica Acta (Elsevier)” and “Scientific Reports (Nature Publishing Group)” and guest editor for „Catalysis Today“ (Elsevier).
Integrated platform technologies for in-situ detection and quantification of PFAS in environmental water matrices
The growing global concerns to public health from human exposure to per- and polyfluoroalkyl substances (PFAS) requires rapid, sensitive, robust detection technique for environmental source streams. An inexpensive, field-deployable, in-situ sensor for the continuous PFAS monitoring is urgently needed; yet the prevalent in-situ techniques often struggle to strike a balance between the practical sensitivity and selectivity demands of the real-world. To address this challenge, Pacific Northwest National Laboratory is developing an integrated sensor platform technology for rapid, field-deployable, in-situ detection and quantification of PFAS in complex, multicomponent matrices such as groundwater. Our approach relies on the targeted capture of specific PFAS by analyte-specific capture probes immobilized on a platform. The platform acts as an electrode to directly measure PFAS concentration through a proportional change in electrical response upon their capture (an increase in electrode impedance or decrease in current). Multiple approaches such as platform configuration and design and incorporation of additional, sensitive detection modalities have been incorporated in our design strategy to enhance the devce sensitivity. A combination of these approaches have allowed us to achieve detection limits as low as 0.5 ng/L for PFAS detection. This detection limit is significantly lower than the Health Advisory Limit of 70 ng/L recommended by the United States Enviornmental Protection Agency and is unprecedented for in-situ analytical PFAS sensors and even comparable to quantification limits achieved using state-of-the-art ex situ techniques. The key benefits of of this platform is its (1) ability to eliminate matrix interferences; (2) highly sensitive, accurate, and precise quantification capability; and (3) responsiveness to dynamic ranges of PFAS concentrations. This presentation will emphasize on our advances in this platform design and he applcation of our approach for the detection of multiple PFAS, both in simple matrices as well as complex, multi-component streams.
Nanoporous Metal-Organic Frameworks for Efficient Capture of per- and polyfluoroalkyl substances (PFAS) from Aqueous Solutions
Toxic per- and polyfluoroalkyl substances (PFAS) are released into the environment from a number of anthropogenic sources. Because of their high chemical resistance and thermal stabilities, these molecules are routinely used in applications for the semiconductor and photolithography industries and found in fire extinguishers, firefighting foams, and fabric protectors. Their low volatility, high water solubility, and extreme resistance to degradation and continued regular use of such technologies has increased PFAS concentrations in ground water sites to several orders of magnitude higher than the US EPA health advisory level (HAL) for drinking water. Pacific Northwest National Laboratory (PNNL) has recently demonstrated an approach to capture of PFOS from aqueous media using nanoporous, tunable metal organic framework (MOF) materials. These materials demonstrated the excellent capture potential of low concentrations perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) in aqueous solutions. In this presentation, we will emphasize the advances of sorbent design and role of functionalities in nanoporous material for the adsorption of PFAS with different chain lengths and functionalities from aqueous solutions. The effect of metal center, surface functionalities, porosity will be discussed.