Simulations of Stretching a Strong, Flexible Polyelectrolyte: Using Long Chains To Access the Pincus Scaling Regime
Simulations of Stretching a Strong, Flexible Polyelectrolyte: Using Long Chains To Access the Pincus Scaling Regime
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拉伸强而柔韧的聚电解质的模拟：使用长链进入 Pincus 缩放机制
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
O. Saleh
中科院分区：
文献类型：
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作者：
M. Stevens;D. B. McIntosh;O. Saleh
我们提出了一个强有力的充电，灵活的长链长度，特别是集中在中间力制度，平卡斯缩放制度发生的拉伸模拟。我们使用200 mM添加盐的筛选库仑势进行Monte Carlo模拟。单体的数量范围为200至25000，其中包括用于ssDNA测量的实验值5000。模拟力延伸数据在整个力范围内与实验数据相匹配。对于这些长链，平衡结构因子S（k）表明该链具有两种结构区域。在长的长度尺度上，静电是完全屏蔽的，链是一个自避免的随机行走与弗洛里指数为3/5。在短的长度尺度下，该结构表现出双链特征，并且相对于中性链被拉伸。在外力作用下，S（k）在低k时为k，线性标度的范围随着力的增大而单调地向低k扩展。
We present simulations of the stretching of a strongly charged, flexible polyelectrolyte chain for long chain lengths particularly focusing on the intermediate force regime, where the Pincus scaling regime occurs. We performed Monte Carlo simulations using the screened Coulomb potential for 200 mM added salt. The number of monomers ranges from 200 to 25000, which includes the experimental value of 5000 for measurements on ssDNA. The simulation force–extension data matches the experimental data over the whole range of forces. For these long chains, the equilibrium structure factor S(k) shows that the chain has two structural regimes. At long length scales, where the electrostatics is fully screened, the chain is a self-avoiding random walk with Flory exponent of 3/5. At short length scales the structure exhibits polyelectrolyte character and is stretched relative to a neutral chain. Under an applied force, S(k) ∼ k at low k and the range of the linear scaling expands monotonically to lower k as the force i...
DOI：
10.1063/1.4729371
发表时间：
2012-05
期刊：
The Journal of chemical physics
影响因子：
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作者：
N. M. Toan;D. Thirumalai
通讯作者：
N. M. Toan;D. Thirumalai