Room temperature trimethylamine gas sensor based on aqueous dispersed graphene

A water dispersible graphene polymer nanocomposite was synthesized by solution blending method and deposited on a nylon-6 membrane via vacuum assisted self-assembly (VASA) method to fabricate a flexible material applied as a chemoresistive gas sensor for trimethylamine (TMA). The morphological and structural characterization of graphene/polystyrene-sulfonate nanocomposite were carried out by using Fourier-Transform infrared (FT-IR) spectroscopy, Raman spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy and field-effect scanning electron (FE-SEM) microscope. While, electrical conductivity was measured using a four-point probe measurement. The prepared polymer nanocomposite has a percolation threshold around 0.30% vol. fraction, with a conductivity of 2.45 S/m (rsd = 3.0%, n=3). The response of the composite sensor exhibited linear range from 23 to 183 mg/L (r²=0.95713) and the sensitivity was at 1.72 × 10^-3 ΔR/R mg L^-1. The gas sensor exhibited repeatable response to TMA gas and the calculated limit of detection was at 22.67 mg/L.