Photo (Shudipto Dishari) The Department of Chemical Engineering is proud to announce the Special Seminar for Dr. Shudipto Konika Dishari, Postdoctoral Research Associate, Department of Chemical Engineering, Pennsylvania State. Join us as she presents her lecture on, “Nanoscale Understanding of Ionomers for Energy and Biomedical Applications.” The seminar will take place on Monday, November 10th, in WEB 1680 from 1:30-2:15pm. All are welcome to attend.

Functional ions containing polymers (ionomers) are extensively used in energy and biomedical applications. The in-depth understanding of ionomers and ionomer based materials at nanoscale is the key to developing sustainable technologies. In proton exchange membrane fuel cells (PEMFCs), the ionomer (~2-30 nm thick layer)-catalyst interface behaves very differently as compared to the bulk membrane used in it. While ionomer membranes (several tens of microns thick) have already been widely studied, the properties of ionomer (e.g. Nafion) thin films are relatively unexplored. The understanding of local nanoenvironment within hydrated thin ionomer films has been achieved by incorporating fluorescent rotor and photoacid probes sensitive to local viscosity and proton concentration, respectively. By using these functional dyes, useful insights were gained about hydration induced changes in water-polymer mobility and proton transport properties of Nafion films (70-600 nm thick). The information about local nanoscopic water environment was further validated using complimentary surface characterization techniques.

Ionomer membranes having nanoscale virus retentive pores (~20 nm dia) are also potentially important for sterile bio-therapeutics. Earlier evidences show that size exclusion based parvovirus (~25 nm dia) retention within virus filtration membranes can decrease in course of filtration during constant pressure filtration operation. The phage passage through membrane can increase severely if there is a transient pressure release during constant pressure filtration. To offer a true explanation of virus capture, it is very important to know where the viruses are getting captured within the membranes and how the pressure release affects the location of virus capture. A new two-fluorescent dye based approach has been proposed to directly visualize, track and differentiate between virus particles captured before and after pressure release using confocal microscopy. Virus retention was quantified using plaque forming unit (pfu) assay. Taken together, the information showed the interesting connections of membrane morphology and pore characteristics with virus retention behavior.

Dr. Shudipto Konika Dishari is a post-doctoral researcher in the Chemical Engineering department at the Pennsylvania State University at Prof. Andrew Zydney’s group. Prior to that, she worked with Prof. Michael Hickner as a post-doc in Materials Science and Engineering at the same university. She graduated from National University of Singapore with a PhD in Chemical and Biomolecular Engineering and got her bachelor (B. S. in Chemical Engineering with Hons.) from Bangladesh University of Engineering and Technology. Throughout her multidisciplinary research career, she has developed a wide spectrum of research experience spanning from energy to biomedical applications. Her research interests include polymers and nanomaterials, energy, chemobiorecognition, virus filtration, thin films and membranes. Her research works on nafion thin films and fluorescence based biosensing have been highlighted as cover stories of ACS Macro Letters and Macromolecular Rapid Communications, respectively. In recognition of excellence in virus filtration membrane research for development of therapies and medical products, she has been selected to receive “Baxter Young Investigator Award” conferred by Baxter Healthcare Corporation.