Structure and Dynamics of Polymers Over Multiple Surfaces

Surface diffusion of macromolecules has potential applications in surface coating, adhesion, DNA sequencing, protein structure analysis, nanotribology etc. Thus, diffusion, relaxation, stretching and  conformation of polymers over surfaces remain important for fundamental understanding as well as engineering applications[1, 2]. Modifying surfaces are also useful  such as  a nano pattern surface can enhance the fractionation of  DNA  compare to  smooth surfaces[3].    

In a recent work[4], we have observed that the electrophoresis  of DNA molecules over a pair of surfaces placed orthogonally becomes faster  than over a single flat surface.  Although the mobility of individual molecule decreases in orthogonal surface, the differences in mobility among molecules of different sizes increase. Chain molecules also elongate along the edge of the orthogonal surface. In this work we have systematically studied the structure and dynamics of polymer over two surfaces with different alignments using Brownian dynamics simulation.  We also investigate the possibilities of controlling the dynamics of polymers using multiple surfaces arranged into specific geometry. We calculate the change in entropy and adsorption energy of polymer when it comes near the surfaces of different arrangements to understand the phenomena.    

References

[1]          D. Mukherji, G. Bartels, and M. H. Muser, Phys. Rev. Letts. 100, 068301 (2008).

[2]          B. Maier, and J. O. Radler, Phys. Rev. Letts. 82, 1911 (1999).

[3]          B. Li et al., Anal. Chem. 78, 4743 (2006).

[4]          A. Ghosh et al., App. Phys. Letts 98, 164102 (2011).