Torkelson Research Group


John Torkelson

Group Members




Alumni of the Torkelson Research Group

Ph.D. Students Graduated

  Xi Chen - Chemical Engineering
   "Dynamic Urethane and Urethane-like Chemistries in Reprocessable Polymer Networks: Structure, Property, and Sustainability"   

  Tong Wei - Chemical Engineering
   "Interfacial and Confinement Effects in Polymer and Polymer Nanocomposites in Absence of Free Surfaces"   

  Lingqiao Li - Chemical Engineering
   "Dynamic Chemistries in Non-linear Polymer Systems: From Applications for Sustainability to Fundamental Theories"

  Kailong Jin - Chemical Engineering
   "Structure, Properties, and Sustainability of Cross-linked Polymeric Materials"
  Lanhe Zhang - Chemical Engineering
   "Distinct Thermophysical Properties Associated with Low Molecular Weight Linear and Cyclic Polymers in Bulk and Confined States: Tg, Fragility, and Thin Film Stability"
  Elizabeth Dhulst - Chemical Engineering
   "Phase-Separated Elastomers: Novel Syntheses and Characterization"
  Goliath Beniah - Chemical Engineering
   "Segmented Polyhydroxyurethane as Novel Non-Isocyanate Polyurethane Functional Materials"
  Shadid Askar - Chemical Engineering
   "Effects of Confinement and Interfaces on Stress Relaxation and Stiffness in Polymer Films and Nanocomposites Characterized by Novel Fluorescence Techniques"

  Tian Lan - Materials Science and Engineering
   "Impact of Confinement and Interfaces on Glass Transition Temperature, Fragility and Small Molecule Diffusivity in Polymers"
  Anthony Tan - Materials Science and Engineering
   "Enhancement and Tunability of the Glass Transition Temperature in Confined Ultrathin Polymer Films, Nanotubes and Nanorods"
  Lawrence Chen - Chemical Engineering
   "Tunability of the Glass Transition Temperature (Tg) of Styrene-based Polymers Confined in Thin Films and Nanospheres"

   Emily Leitsch - Chemical Engineering
   "Polyurethane and Polyurethane-like Materials Synthesized with a Reduced Reliance on Isocyanate Compounds"
   Krishnan Iyer - Chemical Engineering
   "Waste to Wealth: Novel, Green Polymer Composites and Nanocomposites with Superior Properties via Solid-State Shear Pulverization"
   Mirian Diop - Chemical Engineering
   "Solid-State Shear Pulverization: Post-Polymerization Modification of Polypropylene and Dispersion in Polymer Blends"
   Philip Brunner - Materials Science and Engineering
   "Overcoming Sustainability and Energy Challenges in Polymer Science via Solid-State Shear Pulverization"
   Christopher Evans - Chemical Engineering
   "Role of Fragility and Neighboring Domains on the Tg and Surface Wave Dynamics of Nanoconfined Polymers"
   Stephen Marrou - Chemical Engineering
   "Impacts of Repeat Unit Structure and Copolymer Architecture on Thermal and Solution Properties in Homopolymers, Copolymers, and Copolymer Blends"
   Hui Deng - Chemical Engineering
   "The Impacts of Confinement and Neighboring Domains on the Glass Transition Temperature and Mobility Associated with Diffusion in Polymer Films"
   Soyoung Kim - Chemical Engineering
   "Tunability of Glass Transition Temperatures in Nanoscopically Confined Polymer Systems: Impacts of Length Scale, Surfaces and Interfaces"
   Michelle Mok - Materials Science and Engineering
   "Unique Ordering of Gradient Copolymers: Analysis, Consequences and Applications"
   Robert Sandoval - Chemical Engineering
   "Gradient and Block Copolymer Interfacial Behavior: Examination of Physical Properties and the Effects on Compatibilization and Micelle Behavior of Copolymer in Polymer Blends"
   Cynthia Pierre - Materials Science and Engineering
   "Tailoring the Physical Properties of Homopolymers and Polymer Nanocomposites via Solid-State Processing"
   Amanda M. Flores - Chemical Engineering
   "Biobased and Biodegradable Polymer Blends and Nanocomposites with Superior Dispersion and Physical Properties Created Using Solid-State Shear Pulverization"
   Perla Rittigstein - Chemical Engineering
   "The Glass Transition and Physical Aging Behavior of Polymer Nanocomposites Studied via Fluorescence"
   Rodney D. Priestley - Chemical Engineering
   "Effects of Nanoscale Confinement and Interfaces on the Structural Relaxation of Amorphous Polymers Monitored at the Molecular Scale by Fluorescence and Dielectric Spectroscopy"
   Laura M. Dykes - Chemical Engineering
   "In Situ X-ray Scattering Studies of Polymer-Clay Nanocomposites in Simple Shear and Complex Flow"
   Manish K. Mundra - Materials Science and Engineering
   "The Effect of Nanoconfinement on the Glass Transition Temperature (Tg) and Mobility Associated with Diffusion in Polymer Films: A Fluorescence Study"
   Jungki Kim - Chemical Engineering
   "Investigation on the Synthesis, Characterization and Application of a New Type of Copolymer: Gradient Copolymers Made by Controlled Radical Polymerization"
   Ying Tao - Chemical Engineering
   "An Innovative Polymer Processing Method, Solid-State Shear Pulverization (SSSP): Intimate Mixing, Compatibilization, and Basic Understanding of the Process"
   Christopher J. Ellison - Chemical Engineering
   "Probing the Distribution of Glass Transition Temperatures and Related Relaxation Behavior in Thin and Ultrathin Polymer Films Using Novel Fluorescence Approaches"
   Maisha K. Gray - Materials Science and Engineering
   "Exploiting Nitroxide-Mediated Controlled Radical Polymerization: Synthesis of Polymeric Materials and Development of a Novel Method for Study and Application of Diffusion-Controlled Reactions"
   Andrew H. Lebovitz - Chemical Engineering
   "Intimate Mixing and In Situ Compatibilization of Immiscible Polymer Blends via an Innovative Process: Solid-State Shear Pulverization"
   Brian P. Chekal - Chemical Engineering
   "Understanding the Roles of Chemically Controlled and Diffusion-Limited Processes in Determining the Severity of Autoacceleration Behavior in Free Radical Polymerization"
   Jason C. Quirin - Chemical Engineering
   "Fluorescence Sensor Techniques to Examine Heterogeneity in Polymer Systems from the Macroscale to the Nanoscale"
   Manisha Ganglani - Materials Science and Engineering (co-advised with Prof. S. Carr)
   "Influence of Cure via Network Structure on the Mechanical Properties of a Free-Radical Polymerizing Thermoset"
   David B. Hall - Chemical Engineering
   "Experimental Studies of Relaxation Phenomena and Diffusion in Thin and Ultrathin Polymer Films"
   Gregory A. O'Neil - Chemical Engineering
   "An Examination of the Cause of the Gel Effect in Free Radical Polymerization"
   Christopher K. Haas - Chemical Engineering
   "Coarsening in 2D and 3D Phase-Separated Polymer Solutions: Implications for Microporous Membrane Morphology"
   Keith E. Miller - Chemical Engineering
   "Quantitative, In Situ Fluorescence Monitoring of Small-Molecule Sorption in Polymer Coatings"
   Kenneth E. Hamilton - Chemical Engineering
   "Polymer a-Relaxation Dynamics and Chain Segmental Cooperativity as Monitored by Chromophore Motions and Second Harmonic Generation"
   Jacob C. Hooker - Materials Science and Engineering
   "Complementary Optical Techniques as a Means of Monitoring Relaxation Processes in Amorphous Polymers"
   Denise D. Deppe - Materials Science and Engineering
   "Investigation of Small Molecule Diffusion in Thin Polymer Films Using Fluorescence Nonradiative Energy Transfer"
   Marc B. Wisnudel - Chemical Engineering
   "Investigation of Free Volume Theory and Autoacceleration in Radical Polymerization by Use of Diffusion- Limited Photophysical Interactions in Polymer Solutions"
   Donald C. Davis - Chemical Engineering (co-advised with Prof. M. Petrich)
   "Fundamental Investigations of the Physical Aging and Glass Transition of Amorphous Polymers"
   Ali Dhinojwala - Chemical Engineering
   "Second Harmonic and Its Relationship to Basic Polymer Physics"
   Daniel Boggs - Chemical Engineering
   "Diffusive Transport in Membranes for Immunoisolation"
   Seung-won Song (now Chris Song) - Chemical Engineering
   "Coarsening Effects on Microstructure Formation in Polymer Membranes Produced via Themally Induced Phase Separation"
   Alice S. Mendelsohn - Materials Science and Engineering (co-advised with Prof. M. Olvera)
   "Investigation of Correlations in Polymer Melts, Blends, and Semi-dilute Solution by Fluorescence Nonradiative Energy Transfer Techniques"
   J. Scot Royal - Materials Science and Engineering
   "Amorphous Polymer Relaxations Monitored on the Molecular Scale with Photochromic and Fluorescent Probe Molecules"
   Lora L. Spangler - Chemical Engineering
   "Investigation of Diffusional Processes in Thin Polymer Films Utilizing Novel Fluorescence Techniques"
   Linda S. Flosenzier - Chemical Engineering
   "The Structure-Property Relationship of Polymer Blends Containing Styrene-Butadiene-Styrene Triblock Copolymers"
   Sunny Shen - Chemical Engineering
   "Synthesis and Application of a Novel Photoresponsive Polymer in Controlling Solubility, Miscibility and Volume upon Photoirradiation"
   Mark S. Gebert - Chemical Engineering
   "Diffusion-Limited Interactions in Polymer Solutions: A Study of Polymer-Small Molecule and Polymer-Polymer Interactions Using Phosphorescence Quenching"
   Fu-Jya Tsai (now Daniel Tsai) - Chemical Engineering
   "Asymmetric Polymeric Membranes: On Their Formation by Thermally Induced Phase Separation and the Development of Photoresponsive Composite Membranes"
   Hilary Hampsch (now Lackritz) - Materials Science and Engineering
   "Dopant Orientation and Second Order Nonlinear Optical Properties of Doped Amorphous Polymers"
   Scott Lindsey - Materials Science and Engineering (did 2 years of advising after a professor retired)
   "Charge and Mass Transport in the Ionically Conducting Polymer Poly(propylene oxide-lithium triflate)"
   Daniel H.-S. Yu - Chemical Engineering
   "Small Molecule-Small Molecule Diffusion-Limited Interactions in Polymer Solutions Studied by Phosphorescence Quenching and Free-Volume Theory"
   John G. Victor - Chemical Engineering
   "Photochromic Molecular Probes of Local Free Volume in Polymer Glasses: A New Approach to the Study of Physical Aging"
   Michael D. Major - Chemical Engineering
   "An Examination of the Organization of Block Copolymer Containing Systems by Fluorescence Spectroscopy"
   Paul N. Georgelos - Chemical Engineering
   "On Determining the Origin of the Non-Newtonian Effects Which Dilute Solutions Exhibit in Extensional Flow"

M.S. Thesis Students Graduated

   Xiaobo Lin - Chemical Engineering
   "Glass Transition, Fragility and Physical Aging Behavior of Polymers Modified at Chain End Units"

   Sumeng Hu - Chemical Engineering
   "Sustainability, Structure, and Properties of Polyhydroxyurethanes Synthesized by Cyclic Carbonate Aminolysis"
   Mingxiao Li - Chemical Engineering
   "Tunability of Tg- and Fragility-confinement Effects and Determination Methodology by Ellipsometry"
   Xi Chen - Chemical Engineering
   "Improving the Properties of Polyhydroxyurethanes Synthesized by Cyclic Carbonate Aminolysis"
   Tong Wei - Chemical Engineering
   "Solid-State High-Shear Processing: Overcoming Kinetic and Thermodynamic Limitations in Polymer Composite Preparation"
   Lingqiao Li - Chemical Engineering
   "Complex Material Structures and Their Implications on Material Functions"
   Elizabeth Dhulst - Chemical Engineering
   "Reaction Rate Parameters and Mechanical Properties of Polyhydroxyurethanes Synthesized by Reactions of Cyclic Carbonates and Multifunctional Amines"
   Kailong Jin - Chemical Engineering
   "Glass Transition Behavior of Bulk and Confined, Miscible Polymer Blends"
   Wei Qu - Materials Science and Engineering
   "The Design and Processing of Polymer Blends and Polymer Nanocompositesan Innovative Process: Solid-State Shear Pulverization"
   Philip J. Brunner - Materials Science and Engineering
   "Novel Hybrids of Poly(lactic acid) with Microcrystalline Cellulose: Major Enhancements in Dispersion and Physical Properties Using Solid-State Shear Pulverization"
   Sheldon A. Hewlett - Materials Science and Engineering
   "Probing the Effect of Confinement on Glass Transition and Diffusion Properties of Polymer Thin Films using Fluorescence and Ellipsometry"
   Christopher L. H. Wong - Materials Science and Engineering
   "Gradient Copolymers: Their Self-Assembly in Homopolymers and Thermal Behavior"
   Bryce A. Jones - Chemical Engineering
   "Pyrene-Ene-Labeled Polydimethylsiloxane: A Model Associative Polymer System"
   Naomi Furgiuele - Chemical Engineering
   "Solid-state Shear Pulverization: A Novel Technique for Mixing and Compatibilizing Polymer Blends"
   Manisha Singh - Materials Science and Engineering
   "Mechanochemical Alteration of Ethylene Copolymers"
   Mireya Garcia - Materials Science and Engineering
   "Gradient Copolymer Synthesis via ôLiving?Free Radical Polymerization"
   Fabrizio Meli - Chemical Engineering
   "Studies of the Gel Effect and Conversion Monitoring in the Bulk Free Radical Polymerization of Vinyl Acetate"
   Keith E. Miller - Chemical Engineering
   "In Situ Monitoring of Methyl Methacrylate Polymerization by Fluorescence Quenching of Fluorene"
   John Goldstein - Mechanical Engineering (supervised for seven months after death of original advisor)
   "Weight Gain Studies of Contaminants in Poly(ethylene terephthalate)
   Madeleine Biber - Materials Science and Engineering
   "Physical Properties of Glassy Polymers: Low Molecular Weight Polystyrenes and Their Blends"
   Jeffrey Gerth - Chemical Engineering
   "Studies of Photoplastic Recording Film"
   John Rohlfing - Chemical Engineering
   "SBS Block Copolymers - Modifying Mechanical Properties via Irradiation and Blending with Polystyrene"
   William Schwimmer - Chemical Engineering
   "Polymer Solution Structure as Determined by Photophysical Techniques"
   Fu-Jya Tsai (now Daniel Tsai) - Chemical Engineering
   "Studies of the Self-Absorption Effect in Polystyrene Fluorescence and the Applicability of Excimer Fluorescence to the Investigation of Oligomeric Polystyrene/Polybutadiene Phase Separation"
   Michael D. Major - Chemical Engineering
   "An Inquiry into the Conformational Behavior of Polystyrene Sulfonate"
   John G. Victor - Chemical Engineering
   "Molecular Probe Studies of Free Volume in Glassy Polymers"
   Steven R. Gilbert - Chemical Engineering
   "Polymer Structure and Behavior in Dilute and "Semi-dilute Solution: Determination by Fluorescence Techniques"
   Edward (Ned) J. Gordon - Chemical Engineering
   "Fluorescence Studies of Block Copolymers in Solution and the Solid State"
   Samuel E. Lee - Chemical Engineering
   "Fluorescence Behavior of Styrene-Containing Block Copolymers"

Post-doctoral Fellows
   Albert Davydov - May 1999 to August 2000
   Trisha Sten - June 1999 to August 1999
   Sung Dug (Doug) Kim - May 2000 to March 2002
   Connie Roth - January 2006 to August 2007
   Katsuyuki (Kat) Wakabayashi - February 2006 to August 2007

Research Assistant Professor
   Caroline R. Szczepanski - September 2017 to August 2019

Visiting Scholars and Pre-doctoral Fellows
   Paola Castrillo - April 2007 to June 2007
   Dong Jin Woo - 2005-2006

Additional Graduate Students
   Kosmas Kasimatis
   Masashi Ono

Visiting Research Scientist

   Jun'ichi Masuda (employee of Toray Industries, Inc.) - December 2006 to February 2009

Undergraduate Students and Others
Prof. Torkelson has supervised the research of more than 160 undergraduate students over the past 33 years.  Some of his former undergrad research students are now teaching at universities in the United States.  Several were winners of NSF and NDSEG Graduate Research Fellowships.  Some were winners of the Gotaas Undergraduate Research Award from the Engineering School at Northwestern University.  Prof. Torkelson has also had four high school teachers and two high school students involved in research in his laboratory.