Investigation Of Anti-icing And Deicing Silicone Rubber Coating For Wing Surface

Freezing is a very common natural phenomenon,but often bring human significant property loss and serious security incidents.In particular,more than 15% of air disastersare caused by aircraft icing,so the study on aircraft anti-icing and deicing method is very impotent.Passive methods can increase the contact angle of the surface to prevent the water droplets stay on the surface of the aircraft to achieve the effect of anti-icing and reduce the adhesion of the surface and ice so that the ice can easily fall off under the action of external forces to achieve the effect of deicing by coating the surface with an anti-icing/deicing coating Therefore,the anti-icing and deicing coating is an important solution for aircraft icing problem.Based on the theory of anti-icing and deicingsurface,a room temperature vulcanized silicone rubber anti-icing/deicingcoating with low surface energy and rough surface of micro-nano composite structure was prepared,which meets the requirements of the wing.In particular,the following studies have been completed in this thesis:(a)Firstly,from the perspective of anti-ice,the Young’s model on smooth surface and the Wenzel model and Cassie model on rough surface are studiedaccording to contact angle theory.It is concluded that low surface energy and high surface roughness are two necessary conditions to increase the contact angle.Secondly,it is concluded from the perspective of de-icethat the number of solid fraction determines the surface adhesion force by calculating the surface adhesion work.Lastly,micro-nano composite structure can be able to maintain a stable Cassie model state and have more solid fraction.It is proved that the micro-nano composite structure has excellent anti-icing ability by lager contact angle and lower sliding angle and excellent de-icing ability bysmaller adhesive forcecompared to single-scale rough surface.(b)Two-component condensation RTV silicone rubber was selected as the matrix of wing anti-icing and deicing coating,and the surface energy of the coating was decreased by adding hydroxylfluoroalkylsilanes.Firstly,the samples of orthogonal test were prepared by spin coating method.Secondly,The influence of different raw materials on the contact angle of silicone rubber was compared and analyzed.Lastly,the silicone rubber coating with the largest contact angle was obtained.(c)In view of the poor mechanical properties of silicone rubber and the limited anti-icing and deicingability of single surface roughness coating,thegas phase method silica aerogel was added as a reinforcing agent to the silicone rubber coating.Silane coupling agent KH-570 was used to modify the gas phase method silica aerogel to solve the compatibility problem of the gas phase method silica aerogel and to promote the crosslinking polymerization between the reinforcing agent and the silicone rubber.The optimum proportion of the gas phase method silica aerogel was obtained through the comparison experiment,which made the excellent anti-icingsilicone rubber with the largest contact angle.It is verified that the adhesion strength of the micro-nano conforming silicone rubber coating is lower than that of the single-scale silicone rubber coating,and it has stronger deicing ability.