| Frozen ice on the surface of industrial equipment and building materials brings many problems to people’s normal production life,for example,line damage and traffic paralysis.To address this serious problem,it is important to create material surfaces with anti-icing effect.Numerous studies have shown that superhydrophobic surfaces can reduce the contact area with water droplets and have certain advantages in antiicing.However,when the superhydrophobic surface is below the dew point temperature,the water vapor in the air tends to condense and frost on its surface,which reduces the hydrophobic and anti-icing performance of the surface.Therefore,how to improve the anti-icing performance of superhydrophobic surfaces has become a major problem for researchers.To address this problem,this project uses femtosecond laser to prepare superhydrophobic surfaces with different microstructures and investigate the effect of microstructure on the surface wettability of the material,and improves the hydrophobic and anti-icing properties of the material surface under low temperature conditions by designing and optimizing the surface microstructure.The specific findings and conclusions are as follows.(1)Different microstructures of PTFE surfaces were prepared using femtosecond laser to investigate the effect of microstructure on surface wettability and anti-icing properties.Two new microstructures of Siberian-Cocklebur-like microstructures,square pillars integrated Siberian-Cocklebur-like microstructures as well as the conventional grooved microstructure and square pillars microstructure of polytetrafluoroethylene(PTFE)surfaces were prepared by varying the processing parameters such as the energy,scanning speed and scanning spacing of the femtosecond laser.The characterization of the wettability and anti-icing properties of the above microstructured surfaces revealed that the PTFE surfaces with different microstructures exhibited better hydrophobic properties at room temperature.However,at low temperature,microstructured surfaces with Siberian-Cocklebur-like microstructures,square pillars integrated Siberian-Cocklebur-like microstructures showed better hydrophobic and anti-icing properties compared to the conventional microstructured surfaces.(2)Femtosecond laser was used to prepare grid pattern and hilly microstructured stainless steel surfaces to investigate the effect of microstructure on surface wettability and anti-icing properties.Stainless steel surfaces with different hydrophobic properties were obtained by varying the femtosecond laser processing parameters to prepare grid pattern microstructures with different spacing(100-400 ?m)on the stainless steel surface and treating them with fluorosilane.The wettability test results showed that the hydrophobic properties of the stainless steel surface gradually decreased with the increase of the femtosecond laser scan spacing,in which only the grid pattern microstructure stainless steel surface with a scan spacing of 100 ?m showed good hydrophobic properties at room temperature and low temperature.In addition,by further reducing the scan spacing,a hilly microstructure with a spacing of 60 ?m was prepared on the stainless steel surface,which exhibited good hydrophobic properties at both room temperature and low temperature.In the experiments of water droplet impingement on the low-temperature surface,the hilly microstructure with a scan spacing of 60 ?m and the grid pattern microstructure with a scan spacing of 100 ?m on the stainless steel surface were almost free of ice coverage and showed good anti-icing performance. |
