Construction Of Dual Function Surface With Photothermal And Superhydrophobic Properties And Its Characteristics Of Anti-icing And Deicing

As a normal natural phenomenon,icing brings many inconveniences to people’s production and life in the fields of road traffic,power communication as well as aviation transportation,and even threatens people’s lives.At present,traditional deicing methods such as mechanical,thermal and chemical ones have problems of high energy consumption and environmental pollution.Luckily,the superhydrophobic surface can effectively reduce the adhesion of water on the surface and prolong the icing time due to its unique non-wetting ability,which promises it good application potential in anti-icing and deicing technologies.However,although the superhydrophobic surface has anti-icing function,it still has icing phenomenon in harsh environments.Therefore,it is of great significance to endow the superhydrophobic surface with automatic deicing function.As a renewable green energy,solar energy can be converted into thermal energy by introducing photothermal conversion materials,thus superhydrophobic surfaces will in possession of automatic deicing ability.In this thesis,by using carbon-based photothermal conversion materials and polydimethylsiloxane（PDMS）through different preparation technologies,three groups of dual functional surfaces were constructed with superhydrophobicity and photothermal conversion performance.They can not only achieve anti-icing function through excellent superhydrophobicity,but also improve the surface temperature through photothermal conversion to achieve efficient deicing function,which was also stable and green.The main research contents and conclusions are as follows:（1）With carbon black as photothermal conversion material,flexible PDMS/CB photothermal superhydrophobic film was successfully prepared by combining photolithography with template.The micro array structure on the film surface was optimized by changing the design parameters of the mask and the spin coating conditions,and the effects of column spacing and column height on the hydrophobicity of the film surface were explored.The experimental results showed that the contact angle of the film surface can reach 151.1°,and the rolling angle was less than 7.2°.Compared with the pure PDMS surface without micro-array structure,its icing time was prolonged by 74.2%.Moreover,the introduction of carbon black as photothermal conversion material effectively improved the light absorption performance of the film surface,and the light absorption rate reached 88.2%.Under 1 k W m^-2 light intensity,the surface temperature of the film increased by more than 50.0°C when the carbon black content was 0.20 wt%.Besides,in the single droplet photothermal deicing experiment,the deicing time of the film was shortened by 43.1%.When it came to an ice layer,the deicing time can be shortened by 28.5%.In addition,the film had good flexibility which improved its reliability in practical application.After 20 bending-torsion tests,the film can still maintain the superhydrophobicity.（2）An environmentally friendly fluorine-free PDMS/CB photothermal superhydrophobic coating was successfully prepared by a simple spray,with PDMS as carbon black particle binder.The experimental results showed that when the content of carbon black was 40 wt%,which had been introduced as the photothermal conversion material,the contact angle of the coating surface can reach 154.6°,with the rolling angle as low as 5.8°.Moreover,the optical absorption rate of the coating reached 96.0%in the wavelength range of 250-2500 nm.And the surface temperature of the coating can increase to 81.3°C within 300 s under the illumination intensity of 1 k W m^-2.Furthermore,In the low temperature environment of-15°C,the icing time on the coating surface can be extended to 489 s,about 81.5 times that on the pure aluminum surface.With the synergistic effect of photothermal conversion,the ice layer on the coating surface completely melted within 15 min,and the surface temperature can be increased to 5.8°C.In addition,the coating has good stability,which can effectively prevent the damage of water impact on the coating surface and effectively maintain its superhydrophobicity.At the same time,the coating surface had certain self-cleaning property,which can effectively avoid the influence of sand,dust and other pollutants,and hold its stable and efficient photothermal conversion performance.（3）A CNTs/Si O₂@PDMS photothermal superhydrophobic coating with multi-level structure was constructed using three-dimensional porous grid structure as the skeleton with CNTs the photothermal conversion material.Among them,the design of multi-stage structure can effectively improve the superhydrophobicity and light absorption properties of the coating surface.The experimental results showed that the contact angle of the coating surface reached 157.0°,and the rolling angle was as low as3.2°.Besides,the droplets collided with the coating surface can completely rebound within 27 ms,and the optical absorption rate of the coating can be increased to 97.1%in the wavelength range of 250-2500 nm.Moreover,when the light intensity was 1 k W m^-2,the surface temperature of the coating can be increased to 101.9°C in 300 s;although in the low temperature environment of-20°C,the surface temperature of the coating was still increased to 62.5°C within 15 min,achieving the purpose of rapid deicing.In addition,after 10 icing/deicing cycles and 20 sandpaper frictions,the coating surface still maintained excellent hydrophobicity.This paper contains 41 figures,7 tables and 107 references.