Novel architecture of carbon nanotube decorated poly(methyl methacrylate) microbead vapour sensors assembled by spray layer by layer

For the first time vapour sensors were made by assembling multi-wall carbon nanotube (CNT) decorated poly(methyl methacrylate) microbeads (PMMAB) by spray layer by layer (sLbL). This combination of materials and technique resulted in an original hierarchical architecture with a segregated network of CNT bridging PMMAB. The chemo-resistive behaviour of these conductive polymer nanocomposite (CPC) sensors was studied in terms of sensitivity and selectivity towards standard volatile organic compounds (VOC), as well as quantitativity and reproducibility of responses A_r to methanol, water, toluene and chloroform. Results show that 3D sLbL assembly allows boosting CNT network sensitivity by a factor 2 and selectivity for methanol vapour by a factor of 5. Additionally CNT-PMMAB sensors gave responses proportional to vapour molecules content that could easily be fitted by the Langmuir-Henry-clustering model. Such sensors are thus expected to be good candidates for implementation in electronic noses.