微纳跨尺度结构ZnO表面的壁面减阻特性

通过化学气相沉积方法获得了具有良好超疏水特性的微纳跨尺度结构ZnO表面, 其表面接触角为150.7°.扫描电镜(SEM)的测试结果表明, 样品结构为ZnO微米柱阵列和在上面交织生长的高密度ZnO针状纳米线的复合结构.通过流变仪, 采用分步流动模式对样品表面在不同的剪切速率和不同间距的情况下进行测量, 得到了扭矩与剪切速率之间的关系.进一步选择覆盖硅烷的光滑Si表面作为对比样品, 选用40％的甘油作为试验液体, 当剪切速率接近20 s^-1时, 测试的表面滑移长度为46.8 μm.这表明微纳跨尺度结构的ZnO表面可有效增加流体减阻特性, 有利于制备具有减阻效应的微器件.

Superhydrophobic Drag Reduction Characteristics of The Surface of Micro-nano Hierarchical ZnO Structure

Micro-nano hierarchical ZnO structures with superhydrophobic surfaces were synthesized by chemical vapor deposition. The contact angle of the water droplet on the sample surface was 150.7°. The sample structure of micro-column array with nanoneedles on top was confirmed by SEM. By using the AR-G2 Rheometer with step-by-step measurement mode, the relationship between torque and shear rate was obtained by varying the shear rates and spacing. Smooth silicon surface with silane on top and 40% glycerol were used as comparison. The slip length of the surface was 46.8 μm when the shear rate was 20 s^-1. This indicates that the surface of micro-nano hierarchical ZnO structures is beneficial to increasing the drag properties of the liquid.