Unfolding polyelectrolytes in trivalent salt solutions using dc electric fields: A study by Langevin dynamics simulations

摘要: We study the behavior of single linear polyelectrolytes condensed by trivalent salt under action electric fields through computer simulations. The chain is unfolded when strength field stronger than a critical value. This follows scaling law against length, and exponent −0.77(1), smaller theoretical prediction, −3ν/2 [R. R. Netz, Phys. Rev. Lett. 90, 128104 (2003)], one obtained simulations in tetravalent solutions, −0.453(3) [P.-Y. Hsiao K.-M. Wu, J. Chem. B 112, 13177 (2008)]. It demonstrates that depends sensitively on valence. Hence, it easier to unfold chains multivalent Moreover, absolute value electrophoretic mobility increases drastically an field. fact length provides plausible way impart chain-length dependence free-solution electrophoresis via unfolding transition induced fields. Finally, we show that, addition elongated structure, can be into U-shaped structure. formation this structure our purely result polarization, not elastohydrodynamics dominated sedimentation polymers.