亲/疏水纳米结构表面微通道内流体的流动行为

Flow Behavior in Nanostructured Microchannels with Changing Surface Wettability

在毛细管微通道内壁沉积二氧化硅微球并加以亲/疏水改性,以此来构建亲/疏水纳米结构表面微通道,考察了一定粘度的羧甲基纤维素钠水溶液在光滑亲/疏水微通道和粗糙亲/疏水微通道中的流动行为。结果表明,保持压力恒定,光滑毛细管(基材)中的液体流量随着粘度和管长的增加而减小;粘度一定,压力增加,无论壁面光滑或粗糙,疏水管中的流量均大于亲水管,且粗糙管中疏水/亲水流量斜率比大于光滑管;在低压时亲水管流量大于疏水管,而高压时恰好相反。采用滑移理论和牛顿运动定律对上述现象进行了解释,本研究以期为合理地操控微通道内的流体流动提供有价值的指导。

Deposition in the capillary wall to silica microspheres with changing surface wettahility, in order to build hydrophilic/hydrophobic and nanostructured micro-channels, the preparation of certain viscosity carboxymethy cellulose sodium aqueous solution, its flow behavior in the substrate capillary and the capillary modification were examined. The results show that keeping the pressure constant, the flux of substrate capillary liquid decreases with increasing viscosity, with the tube length increasing. The viscosity is 14cP, as the pressure increasing, the flux of hydrophobic channel is faster than hydrophilic channel, and the rough channel of hydrophobic/hydrophilic flow slope ratio is greater than the smooth. It was also found that liquid in hydrophilic channel flows faster than hydrophobic channel in the low-pressure and high pressure was just the opposite, and the slip theory and Newton＇s laws of motion were employed to explain the phenomena. The results provide novel and valuable guidance for rationally manipulating fluid in microchannels.