半刚性聚电解质链与带相反电荷颗粒复合体系的动力学模拟

Langevin dynamics simulation of complex of semiflexible polyelectrolyte chain with oppositely charged particles+

用Langevin动力学研究了半刚性聚电解质链与带相反电荷球状颗粒在溶液中的复合体系,并研究了链的拉伸性质.具体考察了带电颗粒的电量以及溶液中盐离子浓度对复合体系的影响.链两端没有施加外力的情况下,当溶液中盐离子浓度较低时,复合体系呈现一种串珠状结构;当溶液中盐离子浓度较高时,复合体系转变为一种聚集态结构.链的两端施加外力的情况下,带电颗粒从链上脱落的过程可以分为两步.

The complex of semiflexible polyelectrolyte chain with oppositely charged particles and its stretching properties were studied with Langevin dynamics simulation. Attention is focused on the effect of particle charge and salt concentration. When there is no external force, the complex exhibits a beads-on-a-string configuration at low salt concentration and an aggregate configuration at high salt concentration. When external force is applied at the two ends of the chain, the particles unwrap from the chain in two steps with the increasing force.