Study on the flexible superhydrophobic piezoresistive sensor and electrochemical properties of three-dimensional network structure polypyrrole hollow tube/cross-leaf ZIF-L

Abstract

Zeolitic imidazolate framework (ZIF) materials have advantages such as large specific surface area, high porosity, adjustable skeleton structure, and easy functionality, but their poor electrical conductivity limits their application in the field of piezoresistive sensors and electrochemistry. To solve this problem, we prepared polypyrrole hollow tubes on the surface of polyester-cotton fabric using the soft template method and in situ polymerization method, the cross-leaf ZIF-L (L means leaf shape) was grown on the surface of polypyrrole hollow tubes using the in situ growth method, and the properties of piezoresistive sensing, electrochemistry, and surface wettability were tested. The experimental results showed that the three-dimensional network structure polypyrrole hollow tube/cross-leaf ZIF-L composite combined the advantages of polypyrrole hollow tube and ZIF-L materials, and the average sensitivity reaches 6.12 kPa−1, which was 5.3 times that of the polypyrrole hollow tube composite, and 1.9 times that of the cross-leaf ZIF-L composite. As an excellent energy storage material, the specific capacitance was 42.4 F · g−1 at a scan rate of 0.01 V/s. The composite was also an excellent superhydrophobic material, and its contact angle was up to 168.5°, which can facilitate the practical application of sensor materials and electrode materials. Polypyrrole hollow tube/cross-leaf ZIF-L composite had advantages of a simple process, thin thickness, light weight, and low price, and can be widely used in the field of smart wearables.