| Superhydrophobic materials have been widely used in textiles,metal materials,polymers,semiconductors and other fields due to their unique surface structure,such as self-cleaning,anti icing,drag reduction and oil-water separation.In recent years,the preparation technology,application and research of superhydrophobic materials have been highly concerned by industrial and academic circles.At present,most scholars mainly focus on the superhydrophobic research of metal materials.However,there are few reports on the superhydrophobic properties of carbon fiber / epoxy composites.Therefore,the research on the superhydrophobic properties of carbon fiber / epoxy resin composites has very important value and application prospect.In this paper,femtosecond laser,threedimensional white light interferometer,SEM,contact angle test and other related detection equipment are used to study the preparation process parameters of femtosecond laser etching carbon fiber / epoxy resin,the influence of micro nano structure morphology on superhydrophobic properties,and the influence of environmental changes on superhydrophobic surface stability and durability.The main research contents and results are as follows:(1)By changing the average input power of laser to ablate pits with different diameters,fitting the relationship between the square of pit diameter and the logarithm of average input power,the ablation threshold of femtosecond laser etching carbon fiber epoxy resin composites is calculated.On this basis,the average input power,scanning speed,scanning times The influence of scanning distance on the ablation surface morphology and roughness.Aiming at the size of contact angle,the orthogonal test is designed to obtain the best process parameters.The range analysis results show that the primary and secondary order of the influence of surface laser parameters is average power > scanning distance > scanning times > scanning speed,that is,the flat input power is the biggest factor affecting the surface morphology.(2)Based on the process parameters,the parameters are optimized.Three micro nano structure morphologies of two-dimensional grating,lattice and three-dimensional mastoid are etched by femtosecond laser.The effect of periodic spacing on the surface contact angle of the three morphologies is studied.The results show that different micro nano junctions have different requirements for periodic spacing,and the optimal periodic spacing is 30 μm、20-30 μm、10 μm.The maximum contact angles of the three structural surfaces modified by fluorosilane are 158,153.6°,158.3°,171.7°,more abundant nanorods and nanoparticles are produced on the surface of mastoid microstructure.According to the size of mastoid structure,the influence of mastoid bottom radius,height and spacing on surface contact angle is discussed.It is found that periodic spacing has the greatest influence on contact angle,and there is a coupling between mastoid bottom radius and height,not independently controllable.(3)Aiming at the superhydrophobic surface of mastoid microstructure,the movement of water droplets on its surface,thermal stability and durability were studied.It was observed by high-speed camera that the water droplets jumped off the surface after jumping 5 times,indicating that the superhydrophobic surface has very low adhesion;The thermal stability test in the temperature span of 100-500℃ shows that the surface contact angle remains unchanged in the environment of100-200℃;After 150 days of long-term storage,the change of contact angle is not obvious.After 72 hours of immersion in water,the contact angle is also greater than 150°,and after 250 hours of immersion,the contact angle is 133.82°,showing better stability and durability. |
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