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The Development of Nanomaterials and “Green” Methods for Separation Science

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The Development of Nanomaterials and “Green” Methods for Separation Science The Development of Nanomaterials and “Green” Methods for Separation Science DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Michael C. Beilke Graduate Program in Chemistry The Ohio State University 2015 Dissertation Committee: Dr. Susan V. Olesik, Advisor Dr. Heather Allen Dr. Vicki Wysocki Dr. Abigail Shoben Copyright by Michael C. Beilke 2015 Abstract A primary focus of current separations research is directed toward the reduction of both the diameter and particle size distribution of the material utilized as a stationary phase. The work reported herein follows a common theme. Research is focused on novel approaches for the application of electrospun nanomaterials or the search for improved efficiency in separation science. Electrospinning is a cost-effective and simple technique that relies on repulsive electrostatic forces to generate nanofibers from a conductive polymeric solution. Electrospun nanofibers have proven to be an effective stationary phase in ultra-thin layer chromatography (UTLC), giving more efficient separations in shorter analysis time than traditional particle-based stationary phases. This technology was further enhanced by aligning the nanofibrous mats in a single direction. Aligned electrospun UTLC (AE- UTLC) devices showed improved performance relative to non-aligned electrospun (E- UTLC) phases, demonstrating higher separation efficiency and reduced time of analysis. A major disadvantage of conventional TLC analysis is that the mobile phase velocity decreases with increasing separation distance. Here, the chromatographic performance of electrospun (UTLC) stationary phases were explored with induced forced-flow of mobile phase across the stationary phase with applied potential. This type of forced-flow is used in planar electrochromatography (PEC). Compared to UTLC, improved efficiency resulted from analytes with greater migration distance. ii Utilization of nanofibers to provide a co-reactant electrochemiluminescent determination for nucleobases was examined. Nafion, a cation-exchange polymer becomes electrospun with the aid of a second polymer, poly(acrylic) acid (PAA). Good linear agreement between concentration and the evolution of electrochemiluminescent signal for guanine solutions are demonstrated. A “green” hydrophilic interaction chromatography (HILIC), a liquid-liquid partition mechanism, method for separating mixtures with broad ranges in polarities is explored using enhanced-fluidity mobile phases. Under HILIC conditions, analytes elute with increasing polarity. Enhanced-fluidity liquid chromatography (EFLC) involves the addition of liquefied gas to conventional liquid mobile phases. The liquefied gas provides greater diffusivity and lower viscosity character to the mobile phase. The impact of carbon dioxide addition to a methanol:water mobile phase was studied to optimize HILIC conditions. Additionally, the buffer type, pH, and ionic strength were adjusted to achieve optimal chromatographic performance. For the first time a separation of 16 ribonucleic acid (RNA) nucleosides/nucleotides was achieved in 16 minutes with greater than 1.3 resolution for all analyte pairs. An optimized separation using carbon dioxide:methanol:water mobile phase was compared to methanol:water and acetonitrile:water mobile phases. Based on chromatographic performance parameters (efficiency, resolution, and speed of analysis) and the environmental impact of the mobile phase mixtures, carbon dioxide:methanol:water mixtures are preferred over acetonitrile:water or methanol:water mobile phases for the separation of mixtures of nucleosides and nucleotides. The separation of 16 nucleosides and nucleotides, iii representing a large group of compounds with wide ranging polarities, is taken as an example to assess the usefulness of EFL-HILIC. Addition of gradient elution conditions were also explored to provide reduced analysis time for the wide ranging polar mixture. iv Dedication This document is dedicated to my beautiful wife and our sugar bear along with family lost along my graduate school journey. Grandpa, I miss you and can’t wait to see you again. Aliyah, I will always love you. v Acknowledgments I would like to acknowledge all members of the Olesik research group both past and present for their support both professionally and personally. I would like to especially recognize Cherie (Owens) Pomeranz, Toni Newsome, Martin “The Mick” Beres, and Joe Zewe for helping me get through graduate school. Chemistry talk with Hui Wang during “tea time” helped to not only mold me into a better chemist but also a better person. I wish to extend a special thanks to my research advisor; Dr. Susan Olesik, for her guidance. Thank you for exemplifying what is takes to always forge ahead in your pursuits despite any perceived obstacles encountered along the way. Lastly, I could never have made it this far in school without my family. Mom you are my rock, I am me because of you, thank you. Christina, you my dear sister are special. You have always been there, no matter what, no questions asked, thank you. Granny, I love watching baseball and chatting sports with you (yes he did play for Green Bay 5 year ago), thank you. Dad, your stories are ridiculous. The burger was worth it. The screen was tiny. My cribbage board was finer, thank you. Gary, you have showed me, unwillingly as it may be, how to be responsible and to do things right the first time, thank you. vi Vita 2005................................................................B.S. Chemistry, Missouri Southern State University, Joplin, MO 2007................................................................M.S. Chemistry, Saint Louis University, St. Louis, MO 2008................................................................Analytical Chemist, Aerotek, Chesterfield, MO 2009-2010 ......................................................Graduate Teaching Assistant, Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 2010-2014 ......................................................Nanoscale Science and Engineering Fellow, The Ohio State University, Columbus, OH 2014-Present ..................................................Graduate Research Assistant, The Ohio State University, Columbus, OH Publications M.C. Beilke, M.J. Beres, S.V. Olesik, Gradient enhanced-fluidity liquid hydrophilic interaction chromatography of RNA nucleosides and nucleotides: a “green” technique, J. Chromatogr. A, (submitted 2015). M.C. Beilke, J.W. Zewe, J.E. Clark, S.V. Olesik, Aligned electrospun nanofibers for ultra-thin layer chromatography, Anal. Chim. Acta, (2013), 761, 201-208. vii M.C. Beilke, T.L. Klotzbach, B.L. Treu, D. Sokic-Lazic, R.L. Arechedarra, J. Wildrick, M.J. Moehlenbrock, M. Germain, S.D. Minteer, “Enzymatic biofuel cells,” in Micro Fuel Cells, Burlington, Mass., Elsevier Inc., 2009, pp. 179-241. M.C. Beilke, S.D. Minteer, Immobilization of glycolysis enzymes in hydrophobically modified Nafion, PMSE Preprints, (2006), 94, 556-557. Presentations M.C. Beilke, S.V. Olesik, Electrospun silica nanoparticle/PVP nanofiber mat as a planar electrochromatography stationary phase, The Pittsburgh Conference 2015, New Orleans, LA. M.C. Beilke, S.V. Olesik, Development of electrochemiluminescent electrospun nanofibers, The Pittsburgh Conference 2014, Chicago, IL. M.C. Beilke, S.V. Olesik, Characterization and implementation of ion exchange electrospun nanofibers for nucleic acid detection, The Pittsburgh Conference 2012, Orlando, FL. M.C. Beilke, S.V. Olesik, DNA detection using electrochemiluminescence from electropun nanofibers, The Pittsburgh Conference 2011, Atlanta, GA. M.C. Beilke, S.D. Minteer, Glycolysis biomimic in hydrophobically modified Nafion, The Pittsburgh Conference 2007, Chicago, IL. M.C. Beilke, D. Sokic-Lazic, S.D. Minteer, Enzymatic biomimics for biofuel cell application, The Fuel Cell Seminar 2006, Honolulu, HI. M.C. Beilke, S.D. Minteer, Immobilization of glycolysis enzymes in hydrophobically modified Nafion, ACS National Meeting 2006, Atlanta, GA. Fields of Study Major Field: Chemistry viii Table of Contents Abstract ............................................................................................................................... ii Dedication ........................................................................................................................... v Acknowledgments.............................................................................................................. vi Vita .................................................................................................................................... vii Publications ....................................................................................................................... vii Presentations .................................................................................................................... viii Table of Contents ............................................................................................................... ix List of Tables ................................................................................................................... xiv List of Figures .................................................................................................................. xvi CHAPTER 1: INTRODUCTION ...................................................................................... 1 1.1 Overview ......................................................................................................................
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