二氧化硅疏水涂层的水下减阻性能研究

采用溶胶-凝胶法中的Werner StÖber方法制备二氧化硅颗粒，并添加于聚偏二氟乙烯中，喷涂在钢片表面，制得类似荷叶表面结构的疏水涂层。红外光谱测试结果显示，制备的二氧化硅颗粒纯度较高，副产物少。X射线衍射结果表明，二氧化硅颗粒为无定形结构。疏水涂层表面的扫描电镜照片表明，表面颗粒形貌均一，分散性好，具有仿生微粗糙结构。测得涂层水接触角为133°。减阻测试结果表明，低雷诺数下，减阻率大大高于普通聚偏二氟乙烯树脂，最高可达57.6%。减阻效果受二氧化硅颗粒用量的影响，2.5 g聚偏二氟乙烯加入0.4 g二氧化硅时减阻效果较好。

Study on underwater drag reducing properties of SiO2 hydrophobic coating

SiO₂ particles prepared by the StÖber method，one sort of sol-gel method，was added to polyvinylidene fluoride （PVDF），so that the coating structure on the steel disc was similar to the lotus leaf surface.FT-IR analysis showed the prepared SiO₂ particles were high in purity with little by-products.XRD analysis showed that the structure of SiO₂ microspheres was amorphous.SEM image showed that the SiO₂ particles on the surface of the coating were uniformly distributed with uniform morphology and bionic micro-rough structure.The contact angle of the hydrophobic coating could reach 133°，and the drag reduction test showed the DR rate of the hydrophobic coating was much higher than that of PVDF coating at low reynolds number and it could be as high as 57.6%.The amount of SiO₂ particles could affect the drag reduction at extent，which was better when added  SiO₂ of about 0.4 g into PVDF of 2.5 g.