Polynorbornene-Based Polyelectrolytes with Covalently Attached Metallacarboranes: Synthesis, Characterization, and Lithium-Ion Mobility

• Published in: Macromolecules 2021-07, Vol.54 (14), p.6867-6877
• Main Authors: Li, Jianwei, Fernandez-Alvarez, Roberto, Tošner, Zdeněk, Kozlík, Petr, Štěpánek, Miroslav, Zhigunov, Alexander, Urbanová, Martina, Brus, Jiří, Uchman, Mariusz, Matějíček, Pavel
• Format: Article
• Language: English
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/acs.macromol.1c00350

Metallacarborane clusters, such as COSAN, belong to surface-active and low-coordinating nanosized anions. Therefore, they have been used as separate building blocks in self- and co-assembly. As a step forward, we synthesized via ring-opening metathesis polymerization a novel polyelectrolyte, poly­(norbornene-COSAN), PNC, with metallacarborane anions covalently attached to a polynorbornene backbone. The resulting PNC, with the degree of polymerization around 120, is soluble in polar organic solvents, and it can be deposited on a substrate as separate polymer chains or as multichain aggregates, with the bundle-of-fibril patterning. PNC is miscible with polyethylene oxide (PEO), forming the PNC/PEO composite. As shown by solid-state nuclear magnetic resonance spectroscopy, Li+ counterions are firmly coordinated in the PNC matrix, exhibiting rather restricted dynamics. In contrast, the mixing of PNC with PEO leads to a substantial increase of Li+ dynamics. As the result, the mobility of Li+ in the PNC/PEO composite remains almost unrestrained, which makes the COSAN-containing polyelectrolytes promising candidates for ion-conducting materials.