Sat, 05 Jul 2008 00:15:00 BST CiteULike: dchen Qian http://www.citeulike.org/user/dchen/author/Qian CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2552968 <i>Physical Review Letters, Vol. 99, No. 6. (2007)</i><br /><br />Comprehensive three-dimensional dissipative particle dynamics simulations are carried out to elucidate the diffusion mechanism of a strongly adsorbed polymer chain on a solid surface in dilute solutions. We find Rouse and reptation dynamics for polymer chain diffusing on smooth and rough surfaces (with obstacles or sticking points), respectively. Combining with scaling analysis, we find that the interactions between the surface and the fluid screen the hydrodynamic interaction. The different scaling as found for a polymer chain diffusing on a fluid membrane [Phys. Rev. Lett. 82, 1911 (1999)] and on a solid surface [Nature (London) 406, 146 (2000)] may be explained by the solid surface inhomogeneity that induces reptation. Surface Diffusion Dynamics of a Single Polymer Chain in Dilute Solution Hu Qian Li Chen Zhong Lu Ze Li doi:10.1103/PhysRevLett.99.068301 Physical Review Letters, Vol. 99, No. 6. (2007) 2008-03-18T21:08:38-00:00 2007 Physical Review Letters 99 6 APS 2007 diffusion people polymer surface http://www.citeulike.org/user/dchen/article/2547973 <i>Physical Review Letters, Vol. 100, No. 7. (2008)</i><br /><br />The deformation of an elastic rod rotating in a viscous fluid is considered, with applications related to flagellar motility. The rod is tilted relative to the rotation axis, and experiments and theory are used to study the shape transition when driven either at constant torque or at constant speed. At low applied torque, the rod bends gently and generates small propulsive force. At a critical torque, the rotation speed increases abruptly, and the rod forms a helical shape with increased propulsive force. We find good agreement between theory and experiment. A simple physical model is presented to capture and explain the essential behavior. Shape Transition and Propulsive Force of an Elastic Rod Rotating in a Viscous Fluid Bian Qian Thomas Powers Kenneth Breuer doi:10.1103/PhysRevLett.100.078101 Physical Review Letters, Vol. 100, No. 7. (2008) 2008-03-18T00:42:13-00:00 2008 Physical Review Letters 100 7 APS 2008 rotation