Rational structural design of vanillin based vitrimers in one-pot to facilely fabricate highly stretchable and sensitive composite strain sensor

Abstract

The preparation of high performance and multifunctional strain sensors by a facile fabrication process is highly desirable but still challenging. In this study, vanillin based vitrimers were simply synthesized in one-pot by the combination of thiol-epoxy and amine-aldehyde reactions, which was used for strain sensor fabrication. The reaction kinetics were extensively investigated by 1H NMR analysis to demonstrate the feasibility to prepare vitrimers in one-pot. The physicochemical properties and dynamic natures of vanillin based vitrimers were then analyzed by various techniques, such as FTIR, DSC and rheometer. The mechanical properties of vitrimers were tunable via controlling the structure of crosslinkers. Moreover, it exhibited a strong UV-adsorption ability to potentially protect the human skins. Due to the enhanced interfacial interaction between vitrimers and silver nanowire layers, and the dynamic feature of Schiff base, the fabrication of strain sensors with sandwich-structures could be facilely realized. The strain sensors show a wide linear response range (0–100%) and a high gauge factor (15.8), which was comparable to previous sensors prepared by complicated steps. This study has demonstrated the potential to combine dynamic covalent chemistry and sustainability to overcome the general challenges in the fabrication of high-performance strain sensors.