Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (12): 2537-2542.doi: 10.3866/PKU.WHXB20091133

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Effects of Surface Wettability on Bubbles in Nanochannels

XIE Hui, LIU Chao   

  1. College of Power Engineering, Chongqing University, Chongqing 400030, P. R. China
  • Received:2009-04-20 Revised:2009-07-28 Published:2009-11-27
  • Contact: LIU Chao E-mail:liuchao@cqu.edu.cn

Abstract:

Molecular dynamics simulations were carried out to study the distribution and movement of bubbles in nanochannels with different wettabilities when the fluids were driven by mass force. A method for calculating the velocity of a bubble in a nanochannel was presented. Results reveal that bubbles are present in the middle of nanochannels with hydrophilic surfaces and their velocities are close to but lower than the flow velocity in the middle of the nanochannel. At higher potential energies, the bubbles are larger because the surface absorbs more particles. Otherwise, the bubbles would be smaller. Two bubbles are symmetrical on both surfaces of the nanochannel when their surfaces are superhydrophobic and their velocities are close to but larger than the flow velocity at the edge of the nanochannel. The fluid flow speeds up as the interaction decreases between fluid molecules and wall particles while the slip velocity gradually changes fromnegative to positive.

Key words: Molecular dynamics, Surface wettability, Nanobubble, Nanoflow, Nanochannel

MSC2000: 

  • O647