Preparation Of Multi-wall Carbon Nanotubes/Graphene Oxide/Silicon Rubber Composite Film And Study On Its Humidity-Sensititive Properties

Carbon nanotubes are one-dimensional quantum material structure with specialstructure (tube, large ratio of length to diameter), and it has excellentcharacteristics on electricity, humidity and so on. So it is widely applied in manyfields. However, it is very difficult to diffuse in the polymers. Graphene oxide(GO) is two-dimensional honeycomb lattice structure formed by close-packedcarbon atom. GO presents good dispersal and hydrophilic properties, but itsconductivity is not so well. If those two kinds of material are compoundedtogether, the new material sensitive to humidity, which presents good dispersalproperty and good conductivity, will be obtained.The preparation and characterization of the composite materials withchemically modified carbon nanotubes and graphene oxide are studied in thepaper. In addition, its application in the humidity sensor is also studied in thepaper. Based on the design features of "nano-micron structures"and"composite",o-MWCNTs/GO/RTV composite films are prepared by solution blending method.The modified multi-wall carbon nanotubes and graphene oxide are characterizedby FT-IR、SEM、TEM and XRD. Besides, the characteristics sensitive to thehumidity are investigated. Finally, its mechanism on sensitivity to the humidity isdiscussed in the paper.The results shows that the carboxyl groups and hydroxyl groups appears onthe sidewalls and at the ends of the carbon nanotubes after they were treated bymixed acid, which is benefit to both the adsorption of water molecules and the reaction with the function group on the surface of GO, the three-dimensionalnano-micron structure has been formed. Therefore, the structure has gooddispensability and hydrophilicity, while the compatibility of the silicone rubbermatrix and o-MWCNTs/GO was improved, resulting the sensitivity of theo-MWCNTs/GO/RTV composite films improved.Compared with o-MWCNTs/RTV and GO/RTV, the humidity sensitivity ofo-MWCNTs/GO/RTV composite films which is prepared by solution blendingmethod is increased, response and recovery time has been reduced. In addition，the proportion of o-MWCNTs/GO is optimized. The optimum ratio is that GO/o-MWCNTs is1/3when the relative humidity is in the range of23%-87%. In thecondition，the wet hysteresis of o-MWCNTs/GO/RTV humidity films is5%RH,the sensitivity of it is0.3152/%RH, and the response and recovery time is4s and27s separately. It proves that the prepared o-MWCNTs/GO/RTV composite filmpresents good humidity sensitivity.