Liquid Flow in Rectangular Microchannels with Gradient Wettability Inner Surface Driven by Capillary Force and Gravity

Abstract:

A mathematical model for predicting liquid flow velocity in a rectangular microchannel driven by capillary force and gravity is derived. The model takes into account the additional driving force arising from the wettability gradient on inner surface of a microchannel. The results of model prediction show that the velocity of liquid flow decreases with the length of microchannel and the wettability gradient on channel surface will accelerate the motion of the liquid when the flow-front approaches to the end of the microchannel. The analysis of driving force along the moving path matches well with the flow velocity predicted by the model.

• Periodical: Advanced Materials Research (Volumes 233-235)
• Pages: 1152-1156
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.233-235.1152
• Online since: May 2011
• Authors: Jiang Cheng, Yuhong Tao, Yong Zhang, Zhi Qi Cai, Pi Hui Pi, Xiu Fang Wen, Da Feng Zheng, Zhuo Ru Yang, Long Sheng Lu, Yong Tang
• Keywords: Contact Angle (CA), Driving Force, Flow-Front, Micro-Channel, Wetting Gradient

References

[1] R. Lucas: Kolloid-Z.Vol.23(1918), p.15

[2] E. W. Washburn: Phys. Rev.Vol.17(1921), p.273

[3] T. L. Staples and D. G. Shaffer: Colloids and Surfaces A.Vol.204(2002), p.239

[4] W. R. Jong, T. H. Kuo and S. W. Ho etal.: International Communications in Heat and Mass Transfer.Vol.34(2007), p.186

[5] L. J. Yang, T. J. Yao and Y. C. Tai: J. Micromech. Microeng.Vol.14(2004), p.220

[6] N.Ichikawa,K.Hosokawa and R. Maeda: Journal of Colloid and Interface Science.Vol.280(2004), p.155

[7] M. K. Chaudhury and G. M. Whitesides: Science.Vol.256(1992), p.1539

[8] D. T. Wasan, A. D. Nikolov and H. Brenner: Science.Vol.291(2001), p.605

[9] J. Isaksson, N. D. Robinson and M. Berggren: Thin Solid Films.Vol.515 (2006), p. (2003)

[10] X. Zhu, H. Wang and Q. Liao etal.: Experimental Thermal and Fluid Science. Vol.33(2009), p.947

[11] J. Qu, H. Y. Wu and P. Cheng: International Communications in Heat and Mass Transfer.Vol.35(2008), p.523

[12] H. Shames: Mechanics of Fluids（2nd ed., McGraw-Hill Publications, New York 1982, p.341)