IMX Seminar Series - Co-continuous Nanostructures in Charged Polymer Materials
Nanostructured materials with co-continuous structures, in which each discrete domain is independently interconnected, can simultaneously optimize “orthogonal” properties such as ion transport and mechanical strength. Potential applications include porous membranes, fuel cells, and rechargeable metal batteries. Block polymers have been exploited as templating agents to access such morphologies, for example via ordered periodic phases such as the double gyroid, or by polymerization-induced microphase separation. In such cases the conducting domains are typically ≤ 20 nm in size, which can compromise both mobility and strength. An alternate route involves blending an A–B diblock copolymer with the constituent A and B homopolymers, leading to a disordered bicontinuous microemulsion (BmE) state. We have shown that charge-free ternary A–B/A/B polymer blends universally self-assemble into the thermodynamically stable BmE phase, albeit with carefully designed molecular weights and compositions. The BmE displays globally disordered but locally correlated domains, with tunable characteristic length scales in the range of ca. 20–100 nm, well beyond the domain sizes typically associated with pure diblocks. The interesting question that arises is whether this phase can also be accessed in blends containing charge, where in general the intermolecular interactions are stronger and more long-ranged. We are exploring this issue in two cases: an A–B/A/B ternary system with added salt, and an A–B/A/B system in which one of the polymers is ionomeric.
Bio: Tim Lodge graduated from Harvard in 1975 with a B.A. cum laude in Applied Mathematics. He completed his PhD in Chemistry at the University of Wisconsin in 1980, and then spent 20 months as a National Research Council Postdoctoral Fellow at NIST. Since 1982 he has been on the Chemistry faculty at Minnesota, and in 1995 he also became a Professor of Chemical Engineering & Materials Science. In 2013 he was named a Regents Professor, the University’s highest academic rank.
He has been recognized with the American Physical Society (APS) Polymer Physics Prize (2004), the International Scientist Award from the Society of Polymer Science, Japan, (2009), the 2010 Prize in Polymer Chemistry from the American Chemical Society (ACS), and the Hermann Mark Award (2015) and the Paul Flory Education Award (2018) of the ACS Division of Polymer Chemistry. He has been elected to Fellowship in the American Association for the Advancement of Science, the APS, the ACS, and the Neutron Scattering Society of America. In 2016 he was elected to the American Academy of Arts and Sciences.
From 2001–2017 Tim served as the Editor-in-Chief of the ACS journal Macromolecules. In 2011 he became the founding Editor for ACS Macro Letters. He has served as Chair of the Division of Polymer Physics, APS (1997–8), and as Chair of the Gordon Research Conferences on Colloidal, Macromolecular and Polyelectrolyte Solutions (1998) and Polymer Physics (2000). Since 2005 he has been Director of the NSF-supported Materials Research Science & Engineering Center at Minnesota. He has authored or co-authored over 450 papers in the field of polymer science, and advised or co-advised over 80 PhD students. His research interests center on the structure and dynamics of polymer liquids, including solutions, melts, blends, and block copolymers, with particular emphases on self-assembling systems using rheological, scattering and microscopy techniques.
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- Prof. Klok, Prof. Stellacci & Prof. Tileli