Anti-freezing, moisturizing, resilient and conductive organohydrogel for sensitive pressure sensors

Wenhui Zheng; Lijuan Xu; Yangyang Li; Yudong Huang; Bing Li; Zaixing Jiang; Guolin Gao

doi:10.1016/j.jcis.2021.03.079

Anti-freezing, moisturizing, resilient and conductive organohydrogel for sensitive pressure sensors

J Colloid Interface Sci. 2021 Jul 15:594:584-592. doi: 10.1016/j.jcis.2021.03.079. Epub 2021 Mar 19.

Authors

Wenhui Zheng¹, Lijuan Xu¹, Yangyang Li¹, Yudong Huang¹, Bing Li¹, Zaixing Jiang², Guolin Gao³

Affiliations

¹ MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
² MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China. Electronic address: jiangzaixing@hit.edu.cn.
³ MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China. Electronic address: gaoguol@hit.edu.cn.

PMID: 33780763
DOI: 10.1016/j.jcis.2021.03.079

Abstract

Conductive hydrogels have attracted significant attention in the area of wearable pressure sensors due to their mechanical flexibility, conductivity and self-healing capability. At subzero temperatures, water-based conductive hydrogels unavoidably lose their elasticity and conductivity which limits their practical usages at low temperatures. However, traditional conductive hydrogels are short of moisturizing and anti-freezing ability due to the limitation of pure water solvent, which greatly restricts their application in extreme environments. In this study, an anti-freezing and moisturizing conductive double network organohydrogel was prepared by incorporating thioctic acid (TA) with polyvinyl alcohol-borate (PVA-PB) in carbon nanotubes (CNTs) that were dispersed in water (H₂O) and ethylene glycol (EG). The as-prepared PVA-B-TA-CNTs organohydrogel presented outstanding anti-freezing performance (-60 ^oC), long-term moisturizing property (30 days), excellent stability (400 cycles) and fascinating conductive sensitivity (S = 0.625 kPa^-1). The occurrence of dynamic covalent disulfide bonds and noncovalent hydrogen bonds endow the conductive organohydrogels with brilliant remoldability and self-healing ability, which are significant for practical applications. These remarkable advantages make PVA-B-TA-CNTs organohydrogel to have enormous potential in the application of wearable and flexible pressure sensors, human-healthy monitor, and intelligence devices.

Keywords: Anti-freezing; Conductive organohydrogel; Moisturizing; Pressure sensor.