Polyacrylamide/carboxymethyl chitosan double‐network hydrogels with high conductivity and mechanical toughness for flexible sensors

• Published in: Journal of applied polymer science Vol. 139; no. 16
• Main Authors: Zeng, Runpeng, Lu, Shuxin, Qi, Chuyi, Jin, Lele, Xu, Jinbao, Dong, Zhixian, Lei, Caihong
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 20.04.2022; Wiley Subscription Services, Inc
• Subjects: Acrylamide; Aqueous solutions; Chitosan; Fatigue strength; Ferric chloride; Flexible components; Hydrogels; hydrophilic polymers; Materials science; Materials selection; Mechanical properties; Polyacrylamide; Polymers; Sensors; sensors and actuators; Stretchability; Tensile strength; Toughness; Wrist
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.51993

Conductive hydrogels are ideal candidate materials for flexible sensors, but the integration of satisfactory mechanical performances with high conductivity to meet the requirements for practical applications remains a challenge. Herein, a tough ionically conductive polyacrylamide (PAAm)/carboxymethyl chitosan (CMCs) double‐network (DN) hydrogel is fabricated via in situ polymerization of acrylamide in CMCs aqueous solution, followed by ferric chloride (FeCl3) solution immersing. The PAAm/CMCs‐Fe3+ DN hydrogel demonstrates satisfactory mechanical properties, including sufficient tensile strength (~440 kPa), prominent stretchability (~715%), high toughness (~1658 kJ m−3), and excellent fatigue resistance, as well as superb conductivity up to 3.1 S m−1. Moreover, the ionically conductive DN hydrogel‐based sensors exhibit high sensitivity in a broad strain window (0%–700%) and can accurately, and repeatedly monitor the motions of body joints, such as finger and wrist, exhibiting great potential in applications of flexible sensors.