Viscosity Radius of Polymers in Dilute Solutions: Universal Behavior from DNA Rheology and Brownian Dynamics Simulations

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• 作者：Sharadwata Pan ; Deepak Ahirwal ; Duc At Nguyen ; T. Sridhar ; P. Sunthar ; J. Ravi Prakash
• 刊名：Macromolecules
• 出版年：2014
• 出版时间：November 11, 2014
• 年：2014
• 卷：47
• 期：21
• 页码：7548-7560
• 全文大小：693K
• ISSN：1520-5835

文摘

The swelling of the viscosity radius, 伪_畏, and the universal viscosity ratio, U_畏R, have been determined experimentally for linear DNA molecules in dilute solutions with excess salt, and numerically by Brownian dynamics simulations, as a function of the solvent quality. In the latter instance, asymptotic parameter free predictions have been obtained by extrapolating simulation data for finite chains to the long chain limit. Experiments and simulations show a universal crossover for 伪_畏 and U_畏R from 胃 to good solvents in line with earlier observations on synthetic polymer鈥搒olvent systems. The significant difference between the swelling of the dynamic viscosity radius from the observed swelling of the static radius of gyration is shown to arise from the presence of hydrodynamic interactions in the nondraining limit. Simulated values of 伪_畏 and U_畏R are in good agreement with experimental measurements in synthetic polymer solutions reported previously and with the measurements in linear DNA solutions reported here.