Ultra-Stretchable, Adhesive, Conductive, and Antifreezing Multinetwork Borate Ester-Based Hydrogel for Wearable Strain Sensor and VOC Absorption

作者：Ruixue Wang, Chunjiao Liu, Zaixing Li, Yajuan Li, Xudong Yu · 发表于：ACS Sensors · 年份：2024 · DOI：10.1021/acssensors.4c01567 · 被引用次数：56 · 研究领域：Advanced Sensor and Energy Harvesting Materials、Conducting polymers and applications、Polydiacetylene-based materials and applications

Hydrogels based on borate ester bonds exhibit remarkable tensile strength and self-healing ability, which make them a promising material for various biological research and strain sensor applications. However, in order to meet the practical application of hydrogel strain sensors, they must also show high conductivity, frost resistance, and proper adhesion, which is still a continuous challenge. Herein, a triple network hydrogel was prepared using poly(vinyl alcohol) (PVA) as the first network, ethylene imine polymer (PEI) as the second network, and poly(acrylamide- co -acrylic acid) copolymer (denoted as P(AM-Co-AA)) as the third network. 3-Carboxy-4-fluorophenylboronic acid (CFBS) was used as the cross-linking agent, glycerol (GL) was added to improve low-temperature resistance, and sodium chloride (NaCl) was incorporated to enhance electrical conductivity. The resulting PVA-CFBS@PEI@P(AM-Co-AA) triple network hydrogel exhibited impressive mechanical properties, including ultra tensile strength (4100%, 266.8 kPa), high toughness (6.5 MJ/m 3 ), and low-temperature resistance (−60 °C). Additionally, it demonstrated high conductivity (σ = 1.83 mS/cm). The incorporation of CFBS endowed the hydrogel with excellent self-healing ability, while GL improved low-temperature resistance and strain sensing sensitivity (gauge factor (GF) = 2.8 (0–300%), GF = 5.6 (300–600%), GF = 8.7 (600–1000%)). The prepared hydrogel sensor can repetitively detect and differentiate between a wide range o...