Structural reorganization and crack-healing properties of hydrogels based on dynamic diselenide linkages

Hao Xu; Nao Suzuki; Akira Takahashi; Tomoyuki Ohishi; Raita Goseki; Xu-Ming Xie; Hideyuki Otsuka

doi:10.1080/14686996.2020.1783967

Structural reorganization and crack-healing properties of hydrogels based on dynamic diselenide linkages

Sci Technol Adv Mater. 2020 Jul 22;21(1):450-460. doi: 10.1080/14686996.2020.1783967.

Authors

Hao Xu^{1

2}, Nao Suzuki¹, Akira Takahashi¹, Tomoyuki Ohishi¹, Raita Goseki^{1

3}, Xu-Ming Xie², Hideyuki Otsuka^{1

3}

Affiliations

¹ Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Tokyo, Japan.
² Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University, Beijing, China.
³ Department of Chemical Science and Engineering, Tokyo Institute of Technology, Tokyo, Japan.

Abstract

We report the dynamic behavior of diselenide-containing hydrophilic polyurethanes and hydrogels based on diselenide exchange reactions in an aqueous media. Diselenide-containing linear and cross-linked polyurethanes were synthesized via polyaddition reactions using diselenide-containing diol in combination with pyridinium diol that enhances the hydrophilicity of the polymer chains. The obtained linear polyurethanes underwent photo-induced diselenide exchange reactions with small diselenide compounds and degraded to smaller fragments, confirming the dynamicity of the obtained hydrophilic polyurethanes. The prepared hydrogels displayed characteristic large swelling behavior based on the structural reorganization through diselenide exchange either under photo-irradiation at 365 nm or even in the dark at room temperature. The diselenide-containing hydrogels also showed crack-healing behavior under the same exchanging conditions, presenting the utility of diselenide linkages as simple and useful units to offer high dynamicity to hydrogels.

Keywords: 600 Self-healing materials; Diselenide bond; dynamic covalent chemistry; hydrogel; self-healing.

Grants and funding

This work was supported by KAKENHI grant [17H01205] from the Japan Society for the Promotion of Science (JSPS), JST CREST grant number [JPMJCR1991], Japan, and the Mirai Program (JST, Japan) grant number [JPMJMI18A2].