Stretchable and self-healing polyvinyl alcohol/cellulose nanofiber nanocomposite hydrogels for strain sensors with high sensitivity and linearity. (April 2021)

• Record Type: Journal Article
• Authors: Xu, Kaiwen; Wang, Yufeng; Zhang, Bing; Zhang, Chao; Liu, Tianxi
• Is Part Of: Composites communications. Volume 24(2021)
• Publication Date: 2021-04
• Subjects: Nanocomposite hydrogel -- Cellulose nanofiber -- Self-healing performance -- Strain sensors
• DOI: 10.1016/j.coco.2021.100677
• Languages: English
• ISSNs: 2452-2139

Abstract

Abstract: The development of wearable strain sensors with high sensitivity, linearity and self-healing property is highly demanded. Herein, a simple yet efficient solution compounding method is proposed for fabricating a cellulose nanofiber reinforced borax/polyvinyl alcohol nanocomposite hydrogel (CBPH). The resultant CBPH exhibited largely enhanced ultimate tensile strength (47.1 kPa) and high toughness (213.9 kJ m −3 ) compared with that of neat borax/polyvinyl alcohol hydrogel (3.4 kPa, 44.3 kJ m −3 ), ascribing to efficient load transfer between dynamically hydrogen-bonded cellulose nanofiber and polyvinyl alcohol. Besides, dynamic borate-diol bonds among the CBPH contributed to self-healing performance with a healing efficiency reaching nearly 60%. Due to its large stretchability, high toughness and favorable ionic conductivity, the CBPH was used as a stretchable and self-healing ionic conductor for assembling a wearable strain sensor, showing a high yet linear sensitivity (~1.86) over a wide strain range of 0–100%, fast response time (<240 ms) and stable signal feedbacks for human motion detection. Highlights: Highly stretchable and self-healing nanocomposite hydrogel was fabricated. Nanocomposite hydrogel exhibited enhanced mechanical strength and toughness. Dynamic borate-diol bonds contributed to self-healing performance. Resistive strain sensors exhibited high sensitivity, linearity and reliability.