Aggregation and Solubility of a Model Conjugated Donor-Acceptor Polymer

Published

July 31, 2018

Author(s)

Daniel R. Reid, Nicholas E. Jackson, Alexander J. Bourque, Chad R. Snyder, Ronald L. Jones, Juan de Pablo

Abstract

In organic semiconductors, solution-phase polymer structure and aggregation have a strong influence on device morphology and performance. Thus, understanding solubility of conjugated polymers is crucial for their rational design. Using a combination of atomistic molecular dynamics and free energy sampling algorithms, we examine the aggregation behavior and solubility of the polymer PTB7, and study how polymer architecture can be modified to control aggregation. We demonstrate that free energy sampling can be used to effectively screen polymer solubility in a variety of solvents, but that computed solubility parameters are not predictive. We then study the aggregation of variants of PTB7 including those with linear (octyl), branched (2-ethylhexyl), and cleaved (methyl) side-chains, in a selection of explicit solvents and additives. Energetic analysis of these aggregates demonstrates that while side chains do disrupt polymer backbone stacking, solvent exclusion is a critical factor controlling polymer solubility.

Citation

Journal of Physical Chemistry Letters

Volume

9

Issue

16

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.jpclett.8b01738

Local Download

Keywords

semiconducting polymer, PTB7, solubility, folding, small-angle neutron scattering

Citation

Reid, D. , Jackson, N. , Bourque, A. , Snyder, C. , Jones, R. and de Pablo, J. (2018), Aggregation and Solubility of a Model Conjugated Donor-Acceptor Polymer, Journal of Physical Chemistry Letters, [online], https://doi.org/10.1021/acs.jpclett.8b01738, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=925678 (Accessed October 9, 2025)