Single molecule spectroscopy of polyfluorene chains reveals β-phase content and phase reversibility in organic solvents

Brenlla, A., Tenopala-Carmona, F., Kanibolotsky, A. L., Skabara, P. J. , Samuel, I. D.W. and Penedo, J. C. (2019) Single molecule spectroscopy of polyfluorene chains reveals β-phase content and phase reversibility in organic solvents. Matter, 1(5), pp. 1399-1410. (doi: 10.1016/j.matt.2019.07.020)

Abstract

Conjugated polymers are an important class of organic semiconductors that can be deposited from solution to make optoelectronic devices. Among them, poly(9,9′-dioctylfluorene) (PFO) has distinctive optical properties arising from its ability to adopt an ordered planar conformation (β phase) from a disordered glassy phase (α phase). The β phase has attractive optical properties, but the precise mechanism of its formation in solution remains unknown. Here, we have combined specifically tailored polymer synthesis and surface-passivation strategies to provide the first spectroscopic characterization of single PFO chains in solution at room temperature. By anchoring PFO molecules at one end on an anti-adherent surface, we show that isolated chains can adopt the β-phase conformation in a solvent-dependent manner. Furthermore, we find that individual PFO chains can reversibly switch multiple times between phases in response to solvent-exchange events. The methodology presented here for polymer synthesis and immobilization is widely applicable to investigate other luminescent polymers.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Skabara, Professor Peter and Kanibolotskyy, Dr Oleksandr
• Authors: Brenlla, A., Tenopala-Carmona, F., Kanibolotsky, A. L., Skabara, P. J., Samuel, I. D.W., and Penedo, J. C.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Matter
• Publisher: Elsevier (Cell Press)
• ISSN: 2590-2393
• ISSN (Online): 2590-2385
• Published Online: 09 October 2019
• Copyright Holders: Copyright © 2019 Elsevier Inc.
• First Published: First published in Matter 1(5): 1399-1410
• Publisher Policy: Reproduced in accordance with the publisher copyright policy
• Data DOI: 10.17630/f5836bdf-36a2-48e6-a538-4d03255431bd