Macromolecular Science and Technology Branch, Army Research Laboratory, Aberdeen, Maryland, USA.
J Chem Phys. 2012 Apr 7;136(13):134903. doi: 10.1063/1.3698476.
We develop an alternative polymer model to capture entanglements within the dissipative particle dynamics (DPD) framework by using simplified bond-bond repulsive interactions to prevent bond crossings. We show that structural and thermodynamic properties can be improved by applying a segmental repulsive potential (SRP) that is a function of the distance between the midpoints of the segments, rather than the minimum distance between segments. The alternative approach, termed the modified segmental repulsive potential (mSRP), is shown to produce chain structures and thermodynamic properties that are similar to the softly repulsive, flexible chains of standard DPD. Parameters for the mSRP are determined from topological, structural, and thermodynamic considerations. The effectiveness of the mSRP in capturing entanglements is demonstrated by calculating the diffusion and mechanical properties of an entangled polymer melt.
我们开发了一种替代的聚合物模型，通过使用简化的键-键排斥相互作用来防止键交叉，从而在耗散粒子动力学（DPD）框架内捕获缠结。我们表明，通过应用中间点之间的距离而不是段之间的最小距离的分段排斥势（SRP），可以改善结构和热力学性质。替代方法称为改进的分段排斥势（mSRP），它产生的链结构和热力学性质与标准 DPD 的柔软排斥、柔性链相似。mSRP 的参数是根据拓扑、结构和热力学考虑确定的。通过计算缠结聚合物熔体的扩散和力学性质，证明了 mSRP 捕捉缠结的有效性。
