Construction and Humidity Sensing Properties of Polyvinyl Alcohol/Carbon Nanofibers

With rapid advances in nanotechnology and materials science, the development of high-performance humidity sensors has become a research hotspot. In this work, the porous carbon nanofibers (PCNFs) with controllable nanopore structure were prepared from polyacrylonitrile (PAN)/poly(vinylidene fluoride) (PVDF) blended polymers by electrospinning technique and carbonization method. The low-cost and easily available PCNFs were introduced into the polyvinyl alcohol (PVA) humidity-sensitive system, and the PVA/PCNFs composite nanofibrous humidity-sensitive layer was fabricated on the surface of quartz crystal microbalance (QCM) sensors. The PVA/PCNFs composite nanofiber-modified QCM moisture-sensitive element had good moisture-sensitive response characteristics with a maximum frequency response of −3114 Hz (11%–98% RH), a fitted correlation coefficient of R 2 = 0.9981, and response/recovery times of 36 s/< 1 s and 60 s/< 1 s under low and high humidity conditions, respectively. In addition, the QCM sensor based on PVA/PCNFs nanofibers showed good reproducibility and long-term stability. Compared with other moisture-sensitive elements, the PVA/PCNFs moisture-sensitive element has the characteristics of fast response and easy fabrication, which provides a solution for the preparation of low-cost, high-performance and environmentally friendly moisture-sensitive elements.