Vapour sensing with conductive polymer nanocomposites (CPC): Polycarbonate-carbon nanotubes transducers with hierarchical structure processed by spray layer by layer

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

“…Then the nanocomposite solution mixtures were deposition on interdigitated electrodes (IDEs) by the spray layer-by-layer (sLbL) developed in our group, which allows the control of the sensor's hierarchical conducting architecture. [50][51][52][53][54][55][56] The spray conditions were set as follows:…”

“…During solvent evaporation, CPC microdrops of 50-100 nm size can weld to form a three-dimensional network by percolation that leads to a film of final thickness between hundreds of nanometers and several micrometers, depending on the number of sprayed layers. 51 After fabrication, vQRS were conditioned overnight at 308C in a controlled atmosphere. The type of sensor, a number of layers composing the transducer and average initial resistances (R 0 ) were pure CNT (4 layers)/ R 0 ¼ 58^5 kV, PC-CNT (8 layers)/R 0 ¼ 5.2^1.2 kV, and PC-CNT (12 layers)/R 0 ¼ 65^10 kV, respectively.…”

“…57,58 Other factors influencing the sensitivity of QRS sensor are the nature of the polymer matrix, the conducting nanofiller content, the initial resistance, the chemical nature of analytes, particularly the Flory-Huggins intermolecular interaction parameter (x 12 ) based on the difference in solubility parameters d of the VOC and the polymer. 54 Finally, the selectivity of vQRS to analytes can be tuned by changing the chemical nature of the polymer matrix of the CPC 51 or by grafting organic functions on the surface of the conducting nanofiller.…”

A review on carbon nanotubes in an environmental protection and green engineering perspective

“…The outstanding electrical, electrochemical and optical properties of CNTs aroused the interest of researchers to explore the potential applications of CNTs as sensing elements to detect and monitor the concentration of toxic gases released in the environment (Wei et al, 2006;Bondavalli et al, 2009;Di Francia et al, 2009;Lu et al, 2009;Penza et al, 2009a;Penza et al, 2009b;Zhang and Zhang, 2009). CNTs possess an unique and tunable electronic properties whereby their metallic or semi-conductivity is greatly influenced by their one dimensional cylindrical structure, such as size and chirality.…”

“…For instance, heating the sensor by using ultraviolet (UV) illumination and increasing the flux rate of purging gas can improve gas desorption from the sensor. Efforts have also been made to improve the sensitivity and affinity of CNTbased gas sensors through polymer functionalization (Wei et al, 2006;Lu et al, 2009). Incorporation of CNTs in conducting polymers such as polyaniline and polypyrrole leads to an increase in sensitivity of the sensor toward selected gases or vapors.…”