White graphene reinforced polypyrrole and poly(vinyl alcohol) blend nanocomposites as chemiresistive sensors for room temperature detection of liquid petroleum gases

The authors describe the preparation of PVA/WPPy/hBNNP nanocomposite films by solution casting method from poly(vinyl alcohol) (PVA), water soluble polypyrrole (WPPy), and using hexagonal boron nitride nanoparticles (hBNNP) as a reinforcing filler element. The structural, optical and electrical properties of the material are characterized by FTIR, X-ray diffraction, UV-vis spectroscopy, scanning electron microscopy, atomic force microscopy, thermogravimetric analysis, and by electrochemical impedance spectroscopy. The nanocomposite films are shown to be viable chemiresistive sensors for sensitive and selective detection of liquid petroleum gas (LPG). The effect of hBNNP loading on the sensing performance was investigated. The nanocomposite films possess good mechanical flexibility and improved tensile strength. These PVA/WPPy/hBNNP nanocomposite film showed a maximum sensitivity (S, defined as a signal change compared to pure air) to LPG of up to S = 0.25% at a 600 ppm concentration at room temperature with response/recovery times of similar to 30/32 min for 6 wt% hBNNP loading in a PVA/WPPy matrix. The nanocomposite with 6 wt% filler loading shows good selectivity for LPG over vapors of benzene, chloroform, ethanol and acetone. Therefore, this sensor film is a good candidate for qualitative detection of LPG.