界面性质对流动滑移特性影响的实验研究

Experimental Study of the Characteristic of Fluid Slip in Hydrophilic and Hydrophobic Microchannels

采用分子自组装技术在微圆管道内壁生成一层单分子Octadecyltrichlorosilane(OTS)膜来改变其界面性质,使亲水性管道表面变成疏水性表面。利用亲水性和疏水性表面内径50μm的微管道,通过测量其流量的方法观察了去离子水在不同界面性质表面的管道中的流动滑移情况。实验结果表明,在亲水性表面管道中,去离子水流动的压力-流量关系符合经典的Navier-Stokes方程;去离子水在自组装一层单分子OTS膜管道流动时,由于去离子水在斥水性微管道中的流动出现了表面滑移,其流量增大约8%,去离子水流动的压力-流量关系不再符合经典的Navier-Stokes方程。

The hydrophobic surface was created by coating the microchannel surface with the self assembled monolayer of octadecyltrichlorosilane （ OTS）, and the slip was observed by measuring the flux and pressure drop of deionized water flow in hydrophilic and hydrophobic capillary. Result shows that in the hydrophilic capillary, the relationship between the flux and pressure agrees with the prediction of the conventional Navier-Stokes equation. However, the flux of deionized water flowing in hydrophobic capillary increases 8% ,for the deionized water slips over hydrophobic surface ,and the relationship between the flux and pressure does not agree with the prediction of the conventional Navier - Stokes equation.