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@article{Siemons:2023:10.1073/pnas.2306272120,
author = {Siemons, N and Siemons, N},
doi = {10.1073/pnas.2306272120},
journal = {Proceedings of the National Academy of Sciences of USA},
title = {Controlling swelling in mixed transport polymers through alkyl side-chain physical cross-linking},
url = {http://dx.doi.org/10.1073/pnas.2306272120},
volume = {120},
year = {2023}
}
TY - JOUR
AB - 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.
AU - Siemons,N
AU - Siemons,N
DO - 10.1073/pnas.2306272120
PY - 2023///
SN - 0027-8424
TI - Controlling swelling in mixed transport polymers through alkyl side-chain physical cross-linking
T2 - Proceedings of the National Academy of Sciences of USA
UR - http://dx.doi.org/10.1073/pnas.2306272120
UR - https://doi.org/10.1073/pnas.2306272120
UR - http://hdl.handle.net/10044/1/105968
VL - 120
ER -
Jenny Nelson
Professor of Physics
1007, Huxley Building
South Kensington, London, SW7 2AZ