8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P4.6Fri 911:10-14:00Single chain dynamics of wormlike polyelectrolyte inflow fields by mesoscale simulations and singlemolecule imagingMyung-Suk Chun, 1 Jeong Yong Lee, 2 and Hyun Wook Jung 21 Korea Institute of Science and Technology (KIST), Seongbuk-gu, 136-791, Seoul,South Korea2 Korea University, Seoul, South KoreaUnderstanding of single chain dynamics of charged soft matter has become of great attention innanobio science and technology [1]. Based on our previous studies [2, 3] regarding the developmentof coarse-grained models for wormlike xanthan polyelectrolytes, extended works have beenachieved on the dynamics of its sub-micron sized single chain in flow fields. With nonlinear beadspring(FENE) discretization of a whole chain [4], our Brownian dynamics simulation includesexplicitly both the long-range electrostatic and hydrodynamic interactions between pairs of beads,which do not consider in other research groups. Conformational dynamics (i.e. , gyration radiustensor, static structure factor) and translational diffusion certainly depend on the flow strength andflow type in either simple shear or mixed (extensional-like) flows. Under the condition of highflow strength, long-range electrostatic interactions in the chain are negligible in the extensionallikeflow. We also correlated the static structure factor and scaling relation from the Flory-Edwardsexponent with respect to each flow field. Our mesoscale simulations were verified by the singlemolecule visualization of fluorescein-labeled xanthan using a fluorescence microscope, and thedisplacing motion of an individual molecule in wide microchannels was quantified. The experimentalconsistency confirms the validity of our simulations that model rigorously experimentalsystems of the semiflexible single polyelectrolyte. Present results devoted to the bulk space canserve as a basis for further examining the polyelectrolytes in confined spaces. [1] R. M. D. Jendrejack,D. C. Schwartz, J. J. de Pablo, M. D. Graham, J. Chem. Phys. 120, 2513 (2004). [2] J. Jeon,M. -S. Chun, J. Chem. Phys. 126, 154904 (2007). [3] M. -S. Chun, C. Kim, D. E. Lee, Phys. Rev.E 79, 051919 (2009). [4] M. Doi, S. F. Edwards, The Theory of Polymer Dynamics, Clarendon,Oxford (1986).6