We have used dissipative particle dynamics (DPD) to simulate the self‐assembling behavior of A‐block‐(B‐graft‐C) coil‐comb molecules, in which each B segment is covalently bonded with one C segment. In addition to the composition, we found that by varying any of the interaction parameters between each pair of components I and J, where I, J = A, B, C, we can also induce a series of morphology transitions associated with two length scales. Moreover, we observed that if the length of the BC‐comb block is not long enough, the resulting morphology is mainly in the large‐length‐scale, ordering between the A‐rich and C‐rich domains with most of the B in the interfaces. By increasing the length of the BC‐comb block, one may expect that both B and C can pack orderly to form a lamellar structure. As a result, various experimentally observed structure‐within‐structures have been simulated via DPD.
Summary: The addition of spermidine (SPD) into turbulent flow as a condensing agent showed the abrupt change of turbulent drag reducing (DR) efficiency of λ‐DNA in turbulent flow for the first time. The resultant asymptote DR efficiency explains the origin of those changes, which can be conclusively verified via the electrophoresis experiment. Despite the different fluid conditions, with and without condensing agent, all λ‐DNA molecules possessed the same half‐cut dimension, implying that the discrete change of DNA conformation can dramatically alter the flow characteristics.
Coil‐globule transition of DNA by spermidine. 相似文献