Dissipative particle dynamics (DPD) approach was used to investigate effect of chain rigidity on the pressure driven flow of macromolecular solution in micro-and nanochannels. The macromolecules were modeled with worm-like chains. The effect of chain rigidity on the velocity field in the channel. and the cross-streamline migration of macromolecules were studied. The results show that the flow resistance of chains increases with increasing chain rigidity, which can reduce the velocity of the fluids around the chains, thus the velocity of macromolecular solution in the channel decreases. The DPD simulation results also show that the chains migrate toward the channel centerline with small chain rigidity in the pressure driven flow, and both the migration toward the channel centerline and the thickness of depletion layer near the wall increases with the flow strength. However, with the increase of chain rigidity, the depletion layer at the walls decreases and the macromolecular concentration at the channel centerline also decreases, thus the bimodal distribution of chain center-of-mass becomes more pronounced. These simulation results are agree well with the experimental observations and can be used to design and optimize micro-and nanofluidic devices.
XU Shao-feng, WANG Jiu-gen. Effect of chain rigidity on the flow of macromolecular solution in micro-and nanochannels. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2014, 1(8): 1406-1610.
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