Gas barrier efficiency of clay- and graphene-poly(isobutylene-co-isoprene) nanocomposite membranes evidenced by a quantum resistive vapor sensor cell

A quick and newly developed technique has been applied for the determination of gas barrier properties of nanocomposites using conductive polymer nanocomposite (CPC)-based quantum resistive vapor sensors (vQRS). The potential of this device is demonstrated with two kinds of nanocomposites, i.e. poly(isobutylene-co-isoprene) (IIR) filled with either montmorillonite (MMT) or graphene (GR) nanoplatelets. The calibration curves of vQRS were well fitted with the Langmuir–Henry model, whereas the integral time lag method was successfully used to determine the diffusion coefficient D of nanocomposite membranes. The values obtained allowed to derive fillers' shape factor from the Cussler's model and the results obtained with the vQRS cell show that the diffusion coefficient D of volatile organic compounds (VOC such as toluene at 25°C), through IIR membranes can be significantly decreased by the dispersion of nanoplatelets in the polymer matrix. Quantitatively, the gas barrier efficiency of pristine IIR can be increased of 67% and 80% by the incorporation of only 4.76% m m^{− 1} of Cloisite10A, and 4.76% m m^{− 1} of reduced GR oxide, respectively. Inversely, partially exfoliated expanded graphite and organo-modified clay dispersed without maleic anhydride functions present on poly(isobutylene-co-isoprene) (IIR) result in lower gas barrier efficiency, i.e. 17% and 57%, respectively.