355 nm脉冲(100 kHz)紫外激光刻蚀改性的功率密度对聚碳酸酯 (PC)材料表面润湿性能的影响存在规律性: 当激光功率密度小于 0.27×108 W/cm2时, 可得到亲水性的 PC表面; 当激光功率密度在 1.15×108～10.19×108 W/cm2之间时, 可得到疏水性的表面。用扫描电镜技术 (SEM)和 X射线光电子能谱技术 (XPS), 详细探讨了紫外激光刻蚀改性对 PC表面润湿性能的影响机理。当激光功率密度大于 1.15×108 W/cm2时, 尽管改性后 PC表面的含氧极性基团有所增加, 但由于“ V”字形沟槽结构的存在, 使其表面仍然呈现疏水性。探讨了用 Cassie模型解释在一定的激光功率密度刻蚀改性条件下, PC材料表面的水接触角和润湿性能变化的可行性。

The effect of the etching and modification power density of 355 nm pulse (100 kHz) ultraviolet (UV) laser on the wetting property of the surface of polycarbonate (PC) materials was found to have the following regularity: when the laser power density was less than 0.27×108 W/cm2, a hydrophilic surface of PC was produced; While the laser power density was from 1.15×108 W/cm2 to 10×108 W/cm2, a hydrophobic surface could be obtained. The mechanism of the effect of UV laser etching and modification on the wetting property of PC surface was explored in detail by Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). It was shown that, when laser power density was larger than 1.15×108 W/cm2, the polar groups containing element oxygen on the surface of the modified PC increased. However, the porous microstructure with V type-groove resulted from the laser etching and modification determined the hydrophobicity of the PC surface. The distinct microstructure was able to result in the composite contact of water droplet on the PC surface. When certain laser power density was used to modify the PC surface, the feasibility to explain the changes of the water contact angle and wetting property of PC surface with Cassie model was also investigated.