A Reversible Structural Phase Transition by Electrochemically-Driven Ion Injection into a Conjugated Polymer

Autor:	Lucas Q. Flagg, Christine K. Luscombe, Connor G. Bischak, Tahir Rehman, Chang-Zhi Li, Jonathan W. Onorato, Ramsess J. Quezada, Daniel W. Davies, David S. Ginger, Ying Diao, Kangrong Yan
Rok vydání:	2020
Předmět:	chemistry.chemical_classification Structural phase Colloid and Surface Chemistry chemistry Ion injection General Chemistry Polymer Conjugated system Photochemistry Electrochemistry Biochemistry Catalysis
Zdroj:	Journal of the American Chemical Society. 142:7434-7442
ISSN:	1520-5126 0002-7863
Popis:	We find that conjugated polymers can undergo reversible structural phase transitions during electrochemical oxidation and ion injection. We study poly[2,5-bis(thiophenyl)-1,4-bis(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)benzene] (PB2T-TEG), a conjugated polymer with glycolated side chains. Using grazing incidence wide-angle X-ray scattering (GIWAXS), we show that, in contrast to previously known polymers, this polymer switches between two structurally distinct crystalline phases associated with electrochemical oxidation/reduction in an aqueous electrolyte. Importantly, we show that this unique phase change behavior has important physical consequences for ion-polaron pair transport. Notably, using moving front experiments visualized by both optical microscopy and super-resolution photoinduced force microscopy (PiFM), we show that a laterally propagating ion-polaron pair front in PB2T-TEG exhibits non-Fickian transport, retaining a sharp step-edge profile, in stark contrast to the Fickian diffusion more commonly observed in polymers like P3MEEMT. This structural phase transition is reminiscent of those accompanying ion uptake in inorganic materials like LiFePO
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::915b31c6f6d0b2f008b8f9897634fc99 https://doi.org/10.1021/jacs.9b12769 Zobrazit plný text záznamu