Coupled ionic and electronic transport underpins processes as diverse as electrochemical energy conversion, biological signaling, and soft adaptive electronics. Yet, how chemical environments such as pH modulate this coupling at the molecular scale remains poorly understood. Here, we show that the protonation state of carboxylated polythiophenes provides precise chemical control over ion dynamics, doping efficiency, solvent uptake and mechanical response. The findings establish molecular acidity as a general strategy to program ionic preference and mechanical stability, offering design principles for pH-responsive mixed conductors and soft electronic materials that couple ionic, electronic, and mechanical functionality.
@article{arxiv.2511.09671,
title = {pH Regulates Ion Dynamics in Carboxylated Mixed Conductors},
author = {Zeyuan Sun and Mengting Sun and Rajiv Giridharagopal and Robert C. Hamburger and Siyu Qin and Haoxuan Li and Mitchell C. Hausback and Yulong Zheng and Bohyeon Kim and Heng Tan and Thomas E. Gartner and Elizabeth R. Young and Christopher J Takacs and David S. Ginger and Elsa Reichmanis},
journal= {arXiv preprint arXiv:2511.09671},
year = {2026}
}