研究具有超疏水表面特性的疏水涂层实际防覆冰效果.首先理论分析了水滴在固体表面浸润性影响因素,利用不同硅烷水解缩合反应制备出低表面能的含氟硅树脂,之后引入分形理论在含氟硅树脂中添加二氧化硅微粒制备疏水涂层.观察掺杂微粒的涂层表面微观结构,并测试水滴在不同涂层表面的接触角;为直观分析涂层防覆冰效果,将不同涂层涂覆试验件后在结冰风洞中进行覆冰测试.结果显示掺混不同量级微粒的疏水涂层表面形成复合粗糙结构,有着更好的粗糙度;含氟硅树脂表面水滴接触角较普通硅树脂提升10°,含有不同量级粒径微粒的涂层表面水滴接触角较单一粒径微粒掺混的涂层提升近20°,达到超疏水表面效果;具有复合微观结构的疏水涂层涂覆的试验件在5 m·s-1和15 m·s-1的风速下较无涂层表面覆冰减少率分别达到35.6%和25.9%,较只有一级粗糙结构的表面有效防覆冰时间长,具有较好的防覆冰能力.结果表明本文设计的超疏水涂层达到超疏水表面效果,且具有较好的防覆冰性能.
This paper investigates the anti-icing effect of hydrophobic coating, which has similar characteristics with a superhydrophobic surface. First, the factors affecting the wettability of water droplets on a solid surface were theoretically analyzed. Using hydrolytic condensation reaction, low-surface-energy materials were prepared based on a modified vulcanized silicone resin. Different sizes of silica particles were added in a fluorinated silicone resin to prepare the superhydrophobic coatings, considering the fractal theory. In the coating test characterization phase, the microstructure of the particles-doped coating surface and the contact angle of water droplets on different coating surfaces were investigated and analyzed. To visually analyze the effect of coating anti-icing property, icing tests were carried out in an icing wind tunnel after coating the test pieces by different coatings. The results show that the surface of the hydrophobic coating mixed with particles of different sizes forms a composite microstructure, which has a better roughness. The contact angle test result shows that the contact angle of water droplets on the fluorinated silicone resin-coated surface is 10° higher than that on the ordinary silicone resin-coated surface, and increases by nearly 20° in the coating with different particle sizes compared with the uniformly sized particles coating, thus achieving a superhydrophobic surface effect. The different coated test pieces were set in an icing wind tunnel to test their anti-icing abilities, and the results indicate that the superhydrophobic coating with a fractal structure after being cured does not only have a lower icing weight, which is reduced by 35.6% and 25.9% at the wind speed of 5 m·s-1 and 15 m·s-1, respectively, compared with the uncoated surface, but also has longer anti-icing effect than the uniformly rough surface. Therefore, the designed superhydrophobic coating has an outstanding anti-icing ability. In conclusion, the designed superhydrophobic coating achieves a superhydrophobic surface and has a better anti-icing performance, as confirmed through a series of performance tests.