Controlling swelling in mixed transport polymers through alkyl side-chain physical cross-linking
Artikel i vetenskaplig tidskrift, 2023

Semiconducting conjugated polymers bearing glycol side chains can simultaneously transport both electronic and ionic charges with high charge mobilities, making them ideal electrode materials for a range of bioelectronic devices. However, heavily glycolated conjugated polymer films have been observed to swell irreversibly when subjected to an electrochemical bias in an aqueous electrolyte. The excessive swelling can lead to the degradation of their microstructure, and subsequently reduced device performance. An effective strategy to control polymer film swelling is to copolymerize glycolated repeat units with a fraction of monomers bearing alkyl side chains, although the microscopic mechanism that constrains swelling is unknown. Here we investigate, experimentally and computationally, a series of archetypal mixed transporting copolymers with varying ratios of glycolated and alkylated repeat units. Experimentally we observe that exchanging 10% of the glycol side chains for alkyl leads to significantly reduced film swelling and an increase in electrochemical stability. Through molecular dynamics simulation of the amorphous phase of the materials, we observe the formation of polymer networks mediated by alkyl side-chain interactions. When in the presence of water, the network becomes increasingly connected, counteracting the volumetric expansion of the polymer film.

organic electrochemical devices

conjugated polymers

soft materials

mixed electronic-ionic conductors

structure-property relationships

Författare

Nicholas Siemons

Stanford University

Imperial College London

Drew Pearce

Imperial College London

Hang Yu

Imperial College London

Sachetan M. Tuladhar

Imperial College London

Garrett LeCroy

Stanford University

Rajendar Sheelamanthula

King Abdullah University of Science and Technology (KAUST)

Rawad K. Hallani

King Abdullah University of Science and Technology (KAUST)

Alberto Salleo

Stanford University

Iain McCulloch

King Abdullah University of Science and Technology (KAUST)

Alexander Giovannitti

Chalmers, Kemi och kemiteknik, Tillämpad kemi

Stanford University

Jarvist M. Frost

Imperial College London

J. Nelson

Imperial College London

Proceedings of the National Academy of Sciences of the United States of America

0027-8424 (ISSN) 1091-6490 (eISSN)

Vol. 120 35 e2306272120

Ämneskategorier

Polymerkemi

Fysikalisk kemi

DOI

10.1073/pnas.2306272120

PubMed

37603750

Mer information

Senast uppdaterat

2024-04-23