Electrospun Pan/Pani Fiber Film With Abundant Active Sites For Ultrasensitive Trimethylamine Detection

Trimethylamine (TMA) is a malodorous substance with wide emission sources and can cause serious odor nuisance to residents even under low concentration. However, reliable monitoring technology for low concentration TMA is still a challenge. Herein, polyacrylonitrile/polyaniline (PAN/PANI) fibers with abundant active sites were designed and constructed by increasing the saturation difference between PAN and PANI in the precursor solution using electrospinning. The sensor fabricated with the fiber film (PAN/PANI mass ratio of 1: 0.42) exhibited ultrahigh sensitivity (detection limit below 6 ppb) and excellent repeatability (RSD = 4.7 %, n = 10) to TMA. The effect of increasing the content of PANI on the morphology and the proportion of PANI molecules on the fiber surface were analyzed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and Raman spectroscopy, and the preparation mechanism of the fiber with abundant active sites was proposed. The results demonstrated that increasing saturation difference is an effective method for increasing the number of gas sensing active sites on the fiber surface and thus improving the sensing performance of electrospun conductive polymer fibers.