Research Group Website

Additional Publications:

R.D. Priestley, L.J. Broadbelt, and J.M. Torkelson, “Physical Aging of Ultrathin Polymer Films above and below the Bulk Glass Transition Temperature: Effects of Attractive vs Neutral Polymer-Substrate Interactions Measured by Fluorescence,” Macromolecules 38, 654-657 (2005).

Y. Tao, A.H. Lebovitz, and J.M. Torkelson, “Compatibilizing Effects of Block Copolymer Mixed with Immiscible Polymer Blends by Solid-State Shear Pulverization: Stabilizing the Dispersed Phase to Static Coarsening,” Polymer 46, 4753-4761 (2005).

K.L. Brinker, A.H. Lebovitz, J.M. Torkelson, and W.R. Burghardt, "Porod Scattering Study of Coarsening in Immiscible Polymer Blends," J. Polym. Sci. Part B: Polym. Phys. 43, 3413-3420 (2005).

T.M. Kruse, S.E. Levine, H.-W. Wong, E. Duoss, A.H. Lebovitz, J.M. Torkelson, and L.J. Broadbelt, "Binary Mixture Pyrolysis of Polypropylene and Polystyrene: A Modeling and Experimental Study," J. Anal. Appl. Pyrolysis 73, 342-354 (2005).

K.G. Kasimatis, J.A. Nowell, L.M. Dykes, W.R. Burghardt, T. Ramanathan, L.C. Brinson, and J.M. Torkelson, "Polymer Nanocomposites by Pulverization: Enhanced Properties and Dispersion," SPE ANTEC 63, 1965-1969 (2005).

C.J. Ellison, R.D. Priestley, L.J. Broadbelt, M.J. Mundra, P. Rittigstein, and J.M. Torkelson, "On the Glass Transition and Physical Aging in Nanoconfined Polymers," SPE ANTEC 63, 2350-2354 (2005).

Y. Tao, A.H. Lebovitz, and J.M. Torkelson, "Compatibilizing Immiscible Blends with Block Copolymers and Pulverization," SPE ANTEC 63, 2390-2394 (2005).

B.A. Jones and J.M. Torkelson, "Large Melting Point Depression of 2- to 3-nm Length-Scale Nanocrystals Formed by Self-Assembly of an Associative Polymer: Telechelic, Pyrene-labeled Polydimethylsiloxane," J. Polym. Sci. Part B: Polym. Phys. 42, 3470-3475 (2004).

M.K. Gray, H.Y. Zhou, S.T. Nguyen, and J.M. Torkelson, "Synthesis and Glass Transition Behavior of High Molecular Weight Styrene/4-Acetoxystyrene and Styrene/4-Hydroxystyrene Gradient Copolymers Made via Nitroxide-Mediated Controlled Radical Polymerization," Macromolecules 37, 5586-5595 (2004).

C.M. Dettmer, M.K. Gray, J.M. Torkelson, and S.T. Nguyen, "Synthesis and Functionalization of ROMP-based Gradient Copolymers of 5-Substituted Norbornenes," Macromolecules 37, 5504-5512 (2004).

M.K. Gray, H.Y. Zhou, S.T. Nguyen, and J.M. Torkelson, "Differences in Enthalpy Recovery of Gradient and Random Copolymers of Similar Overall Composition: Styrene/4-Methyl Styrene Copolymers Made by Nitroxide-Mediated Controlled Radical Polymerization," Polymer 45, 4777-4786 (2004).

B.A. Jones and J.M. Torkelson, "Novel Thermoplastic Elastomers Resulting from Gelation of Telechelically Labeled Polydimethylsiloxane," SPE ANTEC 62, 4162-4166 (2004).

A.H. Lebovitz and J.M. Torkelson, "Mixing and Compatibilization of Polymer Blends by Solid-State Shear Pulverization: Effects of Microscopic Composition, Processing Aids, and Pulverization Parameters," SPE ANTEC 62, 2699-2703 (2004).

C.J. Ellison and J.M. Torkelson, "Effects of Free-Surface and Interfacial Layers and Plasticizer Content on the Distribution of Glass Transition Temperatures in Nanoconfined Polymers," SPE ANTEC 62, 2338-2342 (2004).

K.G. Kasimatis and J.M. Torkelson, "Kinetic Stability of the Well-Exfoliated State in Polypropylene-Clay Nanocomposites Made by Solid-State Shear Pulverization," SPE ANTEC 62, 1503-1507 (2004).

B.A. Jones and J.M. Torkelson, "Crystallization and Enthalpy Relaxation of Physically Associating, End-Linked Polymer Networks: Telechelic, Pyrene-Labeled Polydimethylsiloxane," Polym. Bull. 51, 411 (2004).

C.J. Ellison, K.E. Miller, and J.M. Torkelson, "In Situ Monitoring and Drying of Polymer Films and Coatings: Self-Referencing, Nearly Temperature-Independent Fluorescence Sensors," Polymer 45, 2623 (2004).

C.J. Ellison, R.L. Ruszkowski, N.J. Fredin, and J.M. Torkelson, "Dramatic Reduction of the Effect of Nanoconfinement on the Glass Transition of Polymer Films via Addition of Small-Molecule Diluent", Phys. Rev. Lett. 92, 095702 (2004).

R.K. Singh, J.O. Stoffer, T.D. Flaim, D.B. Hall, J.M. Torkelson, "Monohydroxy-hydrazone-functionalized Thermally Crosslinked Polymers for Nonlinear Optics," J. Appl. Polym. Sci. 92, 770 (2004).

C.J. Ellison and J.M. Torkelson, “The Distribution of Glass Transition Temperatures in Nanoscopically Confined Glass Formers,” Nature Materials 2, 695 (2003).

T.M. Kruse, R. Souleimovova, A. Cho, M.K. Gray, J.M. Torkelson, and L.J. Broadbelt, “Limitations in the Synthesis of High Molecular Weight Polymers via Nitroxide-Mediated Controlled Radical Polymerization: Modeling Studies,” Macromolecules 36, 7812 (2003).

M.K. Gray, H.Y. Zhou, S.T Nguyen, and J.M. Torkelson, “Limitations in the Synthesis of High Molecular Weight Polymer via Nitroxide-Mediated Controlled Radical Polymerization: Experimental Studies,” Macromolecules 36, 5792 (2003).

A.H. Lebovitz, M.K. Gray, A.C. Chen, and J.M. Torkelson, “Interpolymer Radical Coupling Reactions during Sonication of Polymer Solutions,” Polymer 44, 2823 (2003).

J.C. Quirin and J.M. Torkelson, “Self-Referencing Fluorescence Sensor for Monitoring Conversion of Non-isothermal Polymerization and Nanoscale Mixing of Resin Components,” Polymer 44, 423 (2003).

A.H. Lebovitz, K. Khait, and J.M. Torkelson, “Submicron Dispersed-Phase Particle Size in Polymer Blends: Overcoming the Taylor Limit via Solid-State Shear Pulverization,” Polymer 44, 199 (2003).

C.J. Ellison and J.M. Torkelson, “Sensing the Glass Transition in Thin and Ultrathin Polymer Films via Fluorescence Probes and Labels,” J. Polym. Sci. Part B Polym. Phys. 40, 2745 (2002).

A.H. Lebovitz, K. Khait, and J.M. Torkelson, “In Situ Block Copolymer Formation during Solid-State Shear Pulverization: An Explanation for Blend Compatibilization via Interpolymer Radical Reactions,” Macromolecules 35, 9716 (2002).

A.H. Lebovitz, K. Khait, and J.M. Torkelson, “Stabilization of Dispersed Phase to Static Coarsening: Polymer Blend Compatibilization via Solid-State Shear Pulverization,” Macromolecules 35, 8672 (2002)

M.K. Gray, M.I. Kinsinger, and J.M. Torkelson, “Diffusion-Controlled Polymer-Polymer Reactions in Bulk: Novel Strategy for Model Experiments and Reactive Compatibilization Using Polymers Synthesized via Controlled Radical Polymerization,” Macromolecules 35, 8261 (2002).

B.P. Chekal and J.M . Torkelson, “Relationship between Chain Length and the Concentration Dependence of Polymer and Oligomer Self-Diffusion in Solution,” Macromolecules 35, 8126 (2002).

S.D. Kim and J.M. Torkelson, “Nanoscale Confinement and Temperature Effects on Associative Polymers in Thin Films: Fluorescence Study of a Telechelic, Pyrene-Labeled Poly(dimethylsiloxane),” Macromolecules 35, 5943 (2002).

C.J. Ellison, S.D. Kim, D.B. Hall, and J.M. Torkelson, “Confinement and Processing Effects on Glass Transition Temperature and Physical Aging in Ultrathin Polymer Films: Novel Fluorescence Measurements,” Eur. Phys. J. E 8, 155 (2002).

M. Ganglani, S.H. Carr, and J.M. Torkelson, “Influence of Cure via Network Structure on Mechanical Properties of a Free-Radical Polymerizing Thermoset,” Polymer 43, 2747 (2002).

M. Ganglani, J.M. Torkelson, S.H. Carr, and K.Khait, “Trace Levels of Mechanochemical Effects in Pulverized Polyolefins, ” J. Appl. Polym. Sci. 80, 671 (2001).

K. Khait and J.M. Torkelson, “A New Polymer Processing Technology for Polymer Blends with Unmatched Viscosity: Solid-State Shear Pulverization,” Internat. Polym. Proc. 15, 343 (2000).

N. Furgiuele, A.H. Lebovitz, K. Khait, and J.M. Torkelson, “Efficient Mixing of Polymer Blends of Extreme Viscosity Ratio: Elimination of Phase Inversion via Solid-state Shear Pulverization,” Polym. Eng. Sci. 40, 1447 (2000).

H. Cao, D.B. Hall, J.M. Torkelson, and C.Q. Cao, “Large Enhancement of Second Harmonic Generation in Polymer Films by Microcavities,” Appl. Phys. Lett. 76, 538 (2000).

N. Furgiuele, A.H. Lebovitz, K. Khait, and J.M. Torkelson, “Novel Strategy for Polymer Blend Compatibilization: Solid-state Shear Pulverization,” Macromolecules 33, 225 (2000).

D.B. Hall, K.E. Hamilton, R.D. Miller, and J.M. Torkelson, “Translational and Rotational Diffusion of Probe Molecules in Polymer Films near Tg: Effect of Hydrogen Bonding,” Macromolecules 32, 8052 (1999).

J.C. Hooker, W.R. Burghardt, and J.M. Torkelson, “Birefringence and Second-order Nonlinear Optics as Probes of Polymer Cooperative Segmental Mobility: Demonstration of Debye-type Relaxation,” J.Chem Phys. 111, 2779 (1999).

K. Khait and J.M. Torkelson, “Solid-State Shear Pulverization of Plastics: A Green Recycling Process,” Polym.-Plast. Tech. Eng. 38, 445 (1999).

G.A. O’Neil and J.M Torkelson, “Modeling Insight into the Diffusion-Limited Cause of the Gel Effect in Free Radical Polymerization,” Macromolecules 32, 411 (1999).

D.B. Hall and J.M. Torkelson, “Small Molecule Probe Diffusion in Thin and Ultrathin Supported Polymer Films,” Macromolecules 31, 8817 (1998).

D.B. Hall, P.Underhill, and J.M.Torkelson, “Spin Coating of Thin and Ultrathin Polymer Films,” Polym. Eng. Sci. 39, 2039 (1998).

D.B. Hall, D.D. Deppe, K.E. Hamilton, A. Dhinojwala, and J.M. Torkelson, “Probe Translational and Rotational Diffusion in Polymers near Tg: Roles of Probe Size, Shape, and Secondary Bonding in Deviations from Debye-Stokes-Einstein Scaling,” J. Non-Cryst. Solids 235, 48 (1998).

G.A. O’Neil, M.B. Wisnudel, and J.M. Torkelson, “An Evaluation of Free Volume Approaches to Describe the Gel Effect in Free Radical Polymerization”, Macromolecules 31, 4537 (1998).

G.A. O’Neil, M.B. Wisnudel, and J.M. Torkelson, “Gel Effect in Free Radical Polymerization: Model Discrimination of Its Cause”, AIChE J. 44, 1226 (1998).

D.B. Hall, R.D. Miller, and J.M. Torkelson, “Molecular Probe Techniques for Studying Diffusion and Relaxation in Thin and Ultrathin Polymer Films”, J. Polym. Sci.: Polym. Phys. Ed. 35, 2795 (1997).

G.A. O’Neil and J.M. Torkelson, “Recent Advances in Understanding the Gel Effect in Free Radical Polymerization,” Trends Polym. Sci. 5, 349 (1997).

G.A. O’Neil and J.M. Torkelson, “On the Proper Use of Concentration Profiles for Determining Polymer Diffusion Coefficients via Fluorescence Nonradiative Energy Transfer,” Macromolecules 30, 5560 (1997).

G.A. O’Neil and J.M. Torkelson, “On the Importance of Including Intermolecular Correlations in the Measurement of Polymer Interdiffusion by Fluorescence Nonradiative Energy Transfer,” Macromol. Theory Simul. 6, 931 (1997).

D.B. Hall, A. Dhinojwala, and J.M. Torkelson, “Translation-Rotation Paradox for Diffusion in Glass-Forming Polymers: The Role of the Temperature Dependence of the Relaxation Time Distribution,” Phys. Rev. Lett. 79, 103 (1997).

C.K. Haas and J.M. Torkelson, "Two-dimensional Coarsening and Phase Separation in Thin Polymer Solution Films," Phys. Rev. E 55, 3191 (1997).

D.B. Hall, J.C. Hooker, and J.M. Torkelson, "Ultrathin Polymer Films near the Glass Transition: Effect on the Distribution of alpha-Relaxation Times As Measured by Second Harmonic Generation," Macromolecules 30, 667 (1997).

S.L. Tracy, J.M. Torkelson, and H.M. Jennings, "Preliminary Investigations into Organic-Inorganic Composite Formation: The System DDAB-H2O-MMA-CaSO4," Mater. Sci. Eng. C 4, 149 (1996).

M.B. Wisnudel and J.M. Torkelson, "Effect of Chain Length on Rates of Diffusion-Limited Small Molecule-Polymer and Polymer-Polymer Reactions: Phosphorescence Quenching Studies," J. Polym. Sci.: Polym. Phys. Ed. 34, 2999 (1996).

D.D. Deppe, R.D. Miller, and J.M. Torkelson, "Small Molecule Diffusion in a Rubbery Polymer near Tg: Effects of Probe Size, Shape, and Flexibility," J. Polym. Sci.: Polym. Phys. Ed. 34, 2987 (1996).

G.A. O'Neil, M.B. Wisnudel, and J.M. Torkelson, "A Critical Experimental Examination of the Gel Effect in Free Radical Polymerization: Do Entanglements Cause Autoacceleration?" Macromolecules 29, 7477 (1996).

M.B. Wisnudel and J.M. Torkelson, "Small-Molecule Probe Diffusion in Polymer Solutions: Studies by Taylor Dispersion and Phosphorescence Quenching," Macromolecules 29, 6193 (1996).

D.D. Deppe and J.M. Torkelson, "Diffusional Dynamics near the Glass Transition in Amorphous Polymer Thin Films," Mater. Res. Soc. Proc. 407, 221 (1996).

D.D. Deppe, A. Dhinojwala, and J.M. Torkelson, "Small-Molecule Probe Diffusion in Thin Polymer Films near the Glass Transition: A Novel Approach Using Fluorescence Nonradiative Energy Transfer," Macromolecules 29, 3898 (1996).

M. B. Wisnudel and J.M. Torkelson, "Use of Taylor Dispersion for the Measurement of Probe Diffusion in Polymer Solutions," AIChE J. 42, 1157 (1996).

Older, Highly Cited, Refereed Publications*

J.G. Victor and J.M. Torkelson, "On Measuring the Distribution of Local Free Volume in Glassy Polymers by Photochromic and Photophysical Techniques," Macromolecules 20, 2241 (1987). (174 citations)

H.L. Hampsch, J. Yang, G.K. Wong, and J.M. Torkelson, "Orientation and Second Harmonic Generation in Doped Polystyrene and Polymethylmethacrylate Films," Macromolecules 21, 526 (1988). (154 citations)

H.L. Hampsch, J. Yang, G.K. Wong, and J.M. Torkelson, "Dopant Orientation Dynamics in Doped Second Order Nonlinear Optical Amorphous Polymers. 1. Effects of Temperature above and below Tg in Corona Poled Films," Macromolecules 23, 3640 (1990). (125 citations)

H.L. Hampsch, J. Yang, G.K. Wong, and J.M. Torkelson, "Second Harmonic Generation in Glassy Polymer Films as a Function of Physical Aging and Dopant Size," Polymer Commun. 30, 40 (1989). (101 citations)

A. Dhinojwala, G.K. Wong, and J.M. Torkelson, "Rotational Reorientation Dynamics of Nonlinear Optical Chromophores in Rubbery and Glassy Polymers: alpha-Relaxation Dynamics Probed by Second Harmonic Generation and Dielectric Relaxation," Macromolecules 26, 5943 (1993). (86 citations)

H.L. Hampsch, J. Yang, G.K. Wong, and J.M. Torkelson, "Dopant Orientation Dynamics in Doped Second Order Nonlinear Optical Amorphous Polymers. 2. Effects of Physical Aging in Corona Poled Films," Macromolecules 23, 3648 (1990). (82 citations)

F.-J. Tsai and J.M. Torkelson, "The Roles of Phase Separation Mechanism and Coarsening in the Formation of Polymethylmethacrylate Asymmetric Membranes," Macromolecules 23, 775 (1990). (76 citations)

H.L. Hampsch, J.M. Torkelson, S.J. Bethke, and S.G. Grubb, "Second Harmonic Generation in Corona Poled, Doped Polymer Films as a Function of Corona Processing," J. Appl. Phys. 67, 1037 (1990). (76 citations)

J.G. Victor and J.M. Torkelson, "Photochromic and Fluorescent Probe Studies in Glassy Polymer Matrices. 3. Effects of Physical Aging and Molar Weight on the Size Distribution of Local Free Volume in Polystyrene," Macromolecules 21, 3490 (1988). (72 citations)

A. Dhinojwala, G.K.Wong, and J.M. Torkelson, "Rotational Reorientation Dynamics of Disperse Red 1 in Polystyrene: alpha-Relaxation Dynamics Probed by Second Harmonic Generation and Dielectric Relaxation," J. Chem. Phys. 100, 6046 (1994). (67 citations)

S.-W. Song and J.M. Torkelson, "Coarsening Effects on Microstructure Formation in Isopycnic Polymer Solutions and Membranes Produced via Thermally Induced Phase Separation," Macromolecules 27, 6389 (1994). (58 citations)

* citation numbers from “web of science” as of October 1, 2003; includes citations with incorrect page or volume or year attributions

Prof. John M. Torkelson
Department of Chemical and Biological Engineering
Northwestern University
2145 Sheridan Road
Evanston, IL 60208-3120

tel: 847/491-7449, 491-3553
fax: 847/491-3728
E-mail Professor Torkelson