Research Of Icing Monitoring And Anti-icing/de-icing Performance Based On Carbon Nanotube/polydimethylsiloxane Composite Coating

Aircraft icing will cause problems such as disturbing the pilot’s vision,deteriorating the aerodynamic shape,reducing engine power and other issues,which will seriously affect flight safety.In order to ensure flight safety,aircraft icing detection technology and de-icing technology are developing vigorously.With the development of aviation material technology,the air-heat deicing and deicing fluid deicing technologies commonly used on traditional aircraft no longer meet the requirements of environmental protection and intelligence.Therefore,a new type of intelligent and environmentally friendly icing detection technology and an integrated solution for de-icing technology is particularly important.In this paper,based on the excellent electrical and thermal conductivity of carbon nanotubes（CNTs）and the excellent high elasticity of polydimethylsiloxane（PDMS）,the CNTs/PDMS flexible composite coating was developed.The details are as follows:1.CNTs/PDMS flexible composites were prepared by filtration,and the effects of carbon nanotube content on the pressure sensing properties and current thermal effect were discussed.The results show that the sensing performance and current thermal effect are optimized with the increase of carbon nanotube content.CNTs/PDMS flexible composites possess high sensing sensitivity of 0.14 kpa^-1 with the pressure range of 4.5k Pa～72 k Pa and excellent repeatability.The maximum equilibrium temperature of CNTs/PDMS flexible composites is 156℃when they are exposed to the input voltage of 4V.The heating rate of CNTs/PDMS flexible composites could reach 2.2℃/s,and15 g ice layer could be melted within 150s.2.In order to overcome the shortcomings of sensing performance of CNTs/PDMS flexible composite coatings,the GR-CNTs/PDMS flexible composite coating was prepared by drip coating method,and the influence of the content ratio of graphene and carbon nanotubes on its sensing performance and current-heat effect was studied.The results show that when the mass ratio of graphene to carbon nanotubes is 3:20,the sensing performance is the best.When the pressure is 0.12 k Pa,the sensitivity is maximum,0.54 k Pa^-1.The current heating effect is positively correlated with the content of graphene.The higher the graphene content,the stronger the current heating effect.When the input voltage is 4V,the maximum equilibrium temperature is 181℃,the heating rate is about 2.3℃/s,and it only takes 120s to melt 15g of ice.3.In order to overcome the shortcomings that CNTs/PDMS flexible composite coatings and GR-CNTs/PDMS flexible composite coatings can only be heated by electric current,the Ni-GR-CNTs/PDMS flexible composite coatings were prepared by blade coating.The influence of the content of nano-nickel powder on its hydrophobicity,sensing performance and induction heating performance was studied.The results show that as the content of nano-nickel powder increases,its hydrophobic performance,sensing performance and induction heating performance also increase.The static contact angle increased from 106°of the sample Ni-GR-CNTs/PDMS-1 to 115°of the sample Ni-GR-CNTs/PDMS-4.In the pressure range of 2.3k Pa～72 k Pa,the sensitivity remains almost unchanged,0.39 k Pa^-1;when the induction heater input voltage is 30V,the maximum equilibrium temperature is 120℃,and it only takes 170s to melt 15g of ice.The CNTs/PDMS flexible composites,GR-CNTs/PDMS flexible composite coatings and Ni-GR-CNTs/PDMS flexible composite studied in this dissertation have all verified their icing detection and deicing functions using a self-made low-temperature platform,indicating that it can be used in the field of aircraft icing detection and de-icing/anti-icing.