Counterion-Mediated Hydrogen Bonding Making Poly(styrenesulfonate)-Based Strong Polyelectrolytes pH-Responsive

Yue Huang; Xiaoxuan Zheng; Shuji Ye; Zan Hua; Guangming Liu

doi:10.1021/jacs.3c05456

Counterion-Mediated Hydrogen Bonding Making Poly(styrenesulfonate)-Based Strong Polyelectrolytes pH-Responsive

J Am Chem Soc. 2023 Sep 27;145(38):20745-20748. doi: 10.1021/jacs.3c05456. Epub 2023 Sep 18.

Authors

Yue Huang¹, Xiaoxuan Zheng², Shuji Ye^{3

4}, Zan Hua⁵, Guangming Liu¹

Affiliations

¹ Hefei National Research Center for Physical Science at the Microscale, Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, Hefei, People's Republic of China 230026.
² School of Emerging Technology, University of Science and Technology of China, Hefei, People's Republic of China 230026.
³ Hefei National Research Center for Physical Science at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, People's Republic of China 230026.
⁴ Hefei National Laboratory, University of Science and Technology of China, Hefei, People's Republic of China 230088.
⁵ The Key Laboratory of Functional Molecular Solids, Ministry of Education, and Department of Materials Chemistry, School of Chemistry and Materials Science, Anhui Normal University, Wuhu, People's Republic of China 214002.

PMID: 37721441
DOI: 10.1021/jacs.3c05456

Abstract

Owing to the well-established fact that poly(styrenesulfonate) (PSS)-based strong polyelectrolytes are pH insensitive, their applications in smart materials have thus been severely limited. However, we demonstrate here that counterion-mediated hydrogen bonding (CMHB) makes the PSS brush pH-responsive. With decreasing pH, more hydrogen bonds are formed between the bound hydronium counterions and the sulfonate (-SO₃^-) groups in the PSS brush. At the microscale, the formation of more hydrogen bonds with decreasing pH leads to a more ordered structure and a larger tilt angle of the -SO₃^- groups in the PSS brush. On the other hand, a range of important physicochemical properties of the PSS brush, including hydration, stiffness, wettability, and adhesion, are responsive to pH, induced by the effect of CMHB on the PSS brush. Our work reveals a clear structure-property relationship for the pH-responsive PSS brush. This work not only provides a new understanding of the fundamental properties of the PSS brush but also greatly extends the applications of PSS-based strong polyelectrolytes.