TIM LODGE

Polymer structure and dynamics, self-assembly

We are pursuing a molecular-level understanding of polymer structure and dynamics. Currently, we are most interested in multicomponent systems -- copolymers, homopolymer blends, and their mixtures -- in solution and in the bulk state. Such materials are of great commercial interest, due primarily to the potential flexibility for tailoring superior combinations of physical properties. The overall scientific challenge is to understand how the thermodynamic interactions among the components control both structure and dynamics. For example, the (net) repulsive interactions between blocks of a block copolymer lead to spontaneous self-assembly into a variety of microstructures, each with a periodicity set by the molecular size, i.e., in the tens of nanometers. The same interactions may cause a blend of the corresponding homopolymers to undergo macroscopic phase separation. However, this separation is often quite slow, and may be arrested (e.g., by vitrification, crystallization, or added copolymer surfactant) to produce interesting morphologies with characteristic dimensions on the micron scale. In these, and other situations under study, the already distinctive dynamic properties of polymers may couple in unexpected ways to structural features.

A host of experimental techniques are employed, including structural probes, such as scattering of light, x-ray, and neutrons, and microscopy. We take particular advantage of cryogenic transmission electron microscopy, to examine micellar structures in water, organic solvents, and ionic liquids, without the need for sample staining. Measurements of collective dynamics, by dynamic light scattering and rheology, are also routinely pursued. Another specialty is chain diffusion using the transient optical grating technique of forced Rayleigh scattering. Finally, most of the polymer samples employed are synthesized in-house.

Awards

• Sustained Research Prize, Neutron Scattering Society of America, 2020
• Paul Flory Education Award, Division of Polymer Chemistry, American Chemical Society, 2018
• Fellow, American Academy of Arts and Sciences, 2016
• Fellow, Neutron Scattering Society of America, 2016
• Fellow, Division of Polymer Chemistry, American Chemical Society, 2016
• Hermann Mark Award, Division of Polymer Chemistry, American Chemical Society, 2015
• Regents Professor, University of Minnesota, 2013
• Elected to University of Minnesota Academy of Distinguished Teachers, 2012
• Postbaccalaureate, Graduate, and Professional Education Award, University of Minnesota, 2012
• Minnesota Award, American Chemical Society Minnesota Section, 2012
• Fellow, American Chemical Society, 2010
• Award in Polymer Chemistry, American Chemical Society, 2010
• International Scientist Award, Society of Polymer Science Japan, 2009
• Fellow, American Association for the Advancement of Science, 2009
• Nelson W. Taylor Award in Materials Science, Penn State University, 2007
• Paul Flory Polymer Research Award, POLYCHAR, 2004
• American Physical Society Polymer Physics Prize, 2004

Selected Publications

• “Methylcellulose Solutions and Gels: Fibril Formation and Gelation Properties”, M. L. Coughlin, L. Liberman, S. P. Ertem, J. Edmund, F. S. Bates, and T. P. Lodge, Prog. Polym. Sci., 112, 101324, 2021. 10.1016/j.progpolymsci.2020.101324
• “Phase behavior of diblock copolymer-homopolymer ternary blends with a compositionally asymmetric diblock copolymer”, B. Zhang, S. Xie, T. P. Lodge, F. S. Bates, Macromolecules, 54, 460-472, 2021. 10.1021/acs.macromol.0c01745
  
• “Salt Dependent Structure in Methylcellulose Fibrillar Gels”, L. Liberman, P. W. Schmidt, M. L. Coughlin, A. Matatyaho, I. Davidovich, J. Edmund, S. P. Ertem, S. Morozova, Y. Talmon, F. S. Bates, T. P. Lodge, Macromolecules, 54, 2090-2100, 2021. 10.1021/acs.macromol.0c02429
• “Quasicrystals and Their Approximants in a Crystalline-Amorphous Diblock Copolymer” A. J. Mueller, A. P. Lindsay, A. Jayaraman, T. P. Lodge, M. K. Mahanthappa, F. S. Bates, Macromolecules, 54, 2647-2660, 2021. 10.1021/acs.macromol.0c02871
•  “Molecular Weight Dependence of Block Copolymer Micelle Fragmentation Kinetics”, J. T. Early, A. Block, K. G. Yager, T. P. Lodge, J. Am. Chem. Soc., 143, 7748-7758, 2021. 10.1021/jacs.1c02147
• “Reevaluation of Poly(ethylene-alt-propylene)-block-Polydimethylsiloxane Phase Behavior Uncovers Topological Close-Packing and Epitaxial Quasicrystal Growth”, A. P. Lindsay, A. Jayaraman, A. J. Peterson, A. J. Mueller, S. J. Weigand, K. Almdal, M. Mahanthappa, T. P. Lodge, F. S. Bates, ACS Nano, 15, 9453-9468, 2021. 10.1021/acsnano.1c02420
• “Development of a PointNet for Detecting Morphologies of Self-Assembled Block Oligomers in Atomistic Simulations”, Z. Shen, Y. Sun, T. P. Lodge, J. I. Siepmann, J. Phys. Chem. B., 125, 5275-5284, 2021. 10.1021/acs.jpcb.1c02389
• “Phase Behavior of Salt-Doped A/B/AB Ternary Polymer Blends: The Role of Homopolymer Distribution”, S. Xie, B. Zhang, F. S. Bates, T. P. Lodge, Macromolecules, 54, 6990-7002, 2021. 10.1021/acs.macromol.1c00928
• “Influence of Charge Fraction on the Phase Behavior of Symmetric Single-Ion Conducting Diblock Copolymers”, B. Zhang, C. Zheng, M. B. Sims, F. S. Bates, T. P. Lodge, ACS Macro Lett., 10, 1035-1040, 2021. 10.1021/acsmacrolett.1c00393
• “Complex Phase Behavior in Particle-Forming AB/ABʹ Diblock Copolymer Blends with Variable Core Block Lengths”, A. P. Lindsay, G. K. Cheong, A. J. Peterson, S. J. Weigand, K. D. Dorfman, T. P. Lodge, F. S. Bates, Macromolecules, 54, 7088-7091, 2021. 10.1021/acs.macromol.1c01290
• “Unusual Lower Critical Solution Temperature Phase Behavior of Poly(benzyl methacrylate) in a Pyrrolidinium-Based Ionic Liquid”, B. R. Carrick, C. L. Seitzinger, T. P. Lodge, Molecules, 26, 4850,  2021.   mdpi.com/1420-3049/26/16/4850/pdf
• “Free Energy Trajectory for Escape of a Single Chain from a Diblock Copolymer Micelle”, S. C. Seeger, K. D. Dorfman, T. P. Lodge, ACS Macro Letters, 10, 1570-1575, 2021. 10.1021/acsmacrolett.1c00508
• “Temperature dependence of chain conformations and fibril formation in solutions of poly(N-isopropylacrylamide)-grafted methylcellulose”, M. L. Coughlin, J. Edmund, F. S. Bates, T. P. Lodge, Macromolecules, 55, 550-558, 2022. 10.1021/acs.macromol.1c02206