Noguchi Hiroshi, Gompper Gerhard
Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich, Germany.
J Chem Phys. 2006 Oct 28;125(16):164908. doi: 10.1063/1.2358983.
The dynamics of membranes is studied on the basis of a particle-based meshless surface model, which was introduced earlier [Phys. Rev. E 73, 021903 (2006)]. The model describes fluid membranes with bending energy and-in the case of membranes with boundaries-line tension. The effects of hydrodynamic interactions are investigated by comparing Brownian dynamics with a particle-based mesoscale solvent simulation (multiparticle collision dynamics). Particles self-assemble into vesicles via disk-shaped membrane patches. The time evolution of assembly is found to consist of three steps: particle assembly into discoidal clusters, aggregation of clusters into larger membrane patches, and finally vesicle formation. The time dependence of the cluster distribution and the mean cluster size is evaluated and compared with the predictions of Smoluchowski rate equations. On the other hand, when the line tension is suddenly decreased (or the temperature is increased), vesicles dissolve via pore formation in the membrane. Hydrodynamic interactions are found to speed up the dynamics in both cases. Furthermore, hydrodynamics makes vesicle more spherical in the membrane-closure process.
基于一种早期引入的基于粒子的无网格表面模型（[《物理评论E》73, 021903 (2006)]）对膜的动力学进行了研究。该模型描述了具有弯曲能的流体膜，对于有边界的膜还描述了线张力。通过将布朗动力学与基于粒子的介观尺度溶剂模拟（多粒子碰撞动力学）进行比较，研究了流体动力学相互作用的影响。粒子通过盘状膜片自组装成囊泡。发现组装的时间演化包括三个步骤：粒子组装成盘状簇，簇聚集形成更大的膜片，最后形成囊泡。评估了簇分布和平均簇大小的时间依赖性，并与斯莫卢霍夫斯基速率方程的预测进行了比较。另一方面，当线张力突然降低（或温度升高）时，囊泡会通过膜上形成孔而溶解。发现流体动力学相互作用在两种情况下都会加速动力学过程。此外，流体动力学使囊泡在膜闭合过程中更接近球形。
