Flexible, superhydrophobic, and electrically conductive polymer nanofiber composite for multifunctional sensing applications

Sensor materials that can detect chemical vapors or mechanical deformation have wide applications in the field of healthcare, flexible electronics, environmental protection, etc. However, it is still challenging to prepare stretchable and multifunctional sensors that can be served as both chemical vapor and strain sensors. Here, a superhydrophobic and stretchable nanofiber composite is prepared by acid modified carbon nanotubes (ACNTs) decoration onto the polyurethane (PU)/polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene (SEBS) nanofibers, followed by the hydrolysis of methyltrichlorosilane (MTS) on the ACNT surface. The introduction of ACNTs and hydrolysate of MTS, namely the polysiloxane, significantly improves the mechanical properties of the blend nanofibrous membrane including the Young's modulus, tensile strength and elongation at break. The superhydrophobicity can be maintained even under corrosive conditions. When served as the chemical vapor sensor, the nanofiber composite displays good selectivity, high sensitivity and low detection limit (1 ppm for the toluene vapor). Also, the nanofiber composite can be used as wearable strain sensors that can detect various body motions. The multifunctional nanofiber composite has potential applications in wearable electronic, electrical nose for gas leakage and smart textile.