【摘要】 根据PA分子基团的化学性质和粒子大小,将PA分子分成DPD粒子,将适当大小的水簇视为溶剂粒子,克服了模拟技巧的困难,首次用耗散粒子动力学(dissipative particle dynamics,DPD)方法模拟了两亲性肽分子PA的自组装相行为。模拟结果表明:在水溶剂的辅助下,在三维纤维状的圆柱聚合体中,这些分子能进行自组装。DPD的模拟结果受溶剂珠粒的大小、温度及PA与溶剂的比例等多种因素的影响。研究同时发现,在圆筒状纤维中,使用5～9个水簇的溶剂粒子可得到PA分子的聚合体。形成纳米纤维聚合体的条件是PA与水珠粒的比值大于1:6,温度高于340 K。筒状聚合体直径的估计值符合实验测量值。更多还原

【Abstract】 The peptide amphiphile(PA)molecules was divided in different bead based on its different chemical nature and size.Dis- sipative Particle Dynamics(DPD)method was carried out to investigate the self-assembly phase behavior of peptide amphiphile(PA) molecules by different size of water cluster as solvents.The simulations showed that these molecules were self-assembled into three-di- mensional fiber-like cylindrical aggregates by the assistance of water solvent.The results of DPD simulation arc sensitive to various fac- tors including the size of solvent bead,temperature,and the bead ratio of PA to solvent.We found that using a 5-water cluster as sol- vent bead gives the best result of the aggregation of PA molecules into cylindrical fibers.We found that using 5 to 9 water cluster and solvent bead gives result of the aggregation of PA molecules into cylindrical fibers.The criteria of forming nanofibers are bead ratios of PA to water larger than 1:6 and temperature above 340 K.The estimated diameter of the cylindrical aggregate agrees well with the ex- perimentally measured value.更多还原