“Diblock Rings as Topological Adhesives at Immiscible Polymer Interfaces”, A. Wijesekera, D. L. Vigil, G. S. Grest, S. Zhang, and T. Ge,* ACS Macro Letters 13, 1311 (2024) Front Cover Article. https://pubs.acs.org/doi/abs/10.1021/acsmacrolett.4c00446

“Molecular Simulations Revealing Effects of Non-concatenated Ring Topology on Phase Behavior of Symmetric Diblock Copolymers”, A. Wijesekera, D. L. Vigil, and T. Ge,* Macromolecules 57, 5092 (2024) Front Cover Article. https://pubs.acs.org/doi/abs/10.1021/acs.macromol.3c02473

 

The Ting Ge group recently published a paper in Macromolecules, which was featured on the front cover of Volume 57, Issue 10, and another in ACS Macro Letters, which was highlighted on the front cover of Volume 13, Issue 10. These two projects involved collaborations with the Center for Integrated Nanotechnologies at Sandia National Laboratories in New Mexico. The findings have been showcased on the website of LAMMPS, a standard molecular simulation package developed by CINT scientists. Andrew Wijesekera, a Ph.D. student in Professor Ge's group, is the first author of both papers. Both projects are supported by Ge’s active NSF CAREER Award for ring polymer research. 

The first paper examines the effects of ring topology on the phase behavior of symmetric diblock ring polymers. The results show that the more compact globular conformations of ring polymers require a higher enthalpic repulsion for lamellar phase separation. Additionally, the lack of a long-lived entanglement network in the compact rings enhances the phase-separation kinetics, suggesting greater ease in processing diblock ring polymers. These findings could inspire the application of ring topology to customize block copolymer morphology for technological uses such as lithography, water purification, and ion transport in batteries.

The second paper demonstrates diblock ring polymers threaded by linear polymer chains as effective topological adhesives at immiscible polymer interfaces. The new microscopic adhesion mechanism revealed is analogous to the hook-and-loop process in Velcro tapes. This mechanism could benefit applications such as the additive manufacturing of polymeric devices and processing polymer blends for recycling and upcycling.