Ultrasensitive and robust self-healing composite films with reinforcement of multi-branched cellulose nanocrystals
writer：Zhaofeng Ouyang , Hou-Yong Yu, Meili Song, Jiaying Zhu , Duanchao Wang
keywords：Functional composites，Mechanical properties，Scanning electron microscopy (SEM)
source：期刊
specific source：Composites Science and Technology
Issue time：2020年
Herein, self-healing multi-branched cellulose nanocrystals/polyvinyl alcohol
(MCNC/PVA) composite films with excellent sensitivity to human motions was
synthesized by employing MCNC as reinforcing agent, where the potassium chloride
(KCl) was added to enhance the conductivity and strain sensitivity of the composite film.
There was a synergistic effect between MCNC and PVA, which could promote the slip
and recombination of hydrogen bonds, so that the films had robust strength (2.2 times to
pure PVA) and high self-healing efficiency (69.54% after 20 min). Especially, the
flexible composite film could clearly monitor both large and subtle human motions
(finger bending, swallowing, breathing, and insect crawling), and showed larger subtle
strain sensitivity (strains <24.5%) with a gauge factor (GF) of 2.4, which was relatively
larger than the GF of ionic hydrogel and film-based skin sensors, which could solve the
current problems of poor mechanical flexibility and low sensitivity of electronic skin,
and had great potential application in the fields of self-healing soft electronic skin
sensors for human motion detection and healthcare.