物理化学学报 >> 1997, Vol. 13 >> Issue (01): 28-35.doi: 10.3866/PKU.WHXB19970106

研究论文 上一篇    下一篇

具有多体效应的胶体聚团的特征

李敬生,P.Mark Rodger   

  1. 西安建筑科技大学冶金系,西安 710055|Dept.of Chem,Univ,of Reading,U.K
  • 收稿日期:1996-05-31 修回日期:1996-07-10 发布日期:1997-01-15
  • 通讯作者: 李敬生

Characteristics of Colloidal Aggregates with Many-body Effect

Li Jing-Sheng,P.Mark Rodger   

  1. Department of Metallurgy,Xi'an University of Architecture and Technology|Dept.of Chem,Univ,of Reading,U.K
  • Received:1996-05-31 Revised:1996-07-10 Published:1997-01-15
  • Contact: Li Jing-Sheng

摘要:


考察了多体效应(用Stutton-Chen势,SC)对胶体聚团的影响并与双体(Lennard-Jones,LJ)势下的结果作了比较. 研究表明,SC和LJ势下簇团的性质有其相似的一面,如: 随着剪应力的增加,系统里颗粒的平均势能增加,而每个簇团的颗粒数减少;在较强的剪应力场里,簇团沿剪应力方向(X轴)被明显拉长且其主轴偏离X轴等. 但它们间的差异也是明显的,在剪应力下SC系统内颗粒排列得更合理,从而使得平均位能比LJ系统低约1-3个对比能量单位,因而簇团较致密,分形维数较高;颗粒的平均位能,平均簇团大小和分形维数对剪应力的依赖均比LJ系统减弱.在某些条件下簇团的形貌特征也发生了一定程度的改变.

关键词: 多体效应, 胶体, 计算机模拟

Abstract:

 Effects of many-body (by Sutton-Chen potential, SC) on colloidal aggregates have been examined and compared with that ot two-body (by Lennard-Jones potential, LJ)Some characteristics were similar in both SC and LJ systems such as potential energy increased, and the number of particles in a cluster decreased with increasing shear rates; clusters were stretched remarkably in shear (X axis) direction and the longest axis of clusters deviated from X axis under stronger shear held; etc. Their differences were also obvious : arrangement of particles in SC system was more reasonable than in LJ system so that the potential energy in SC system was lower 1-3 dimensionless energy units, thereby clusters in SC system were closer and their fractal dimension higher; dependent of petential energy for particles, average cluster size and fractal dimension on shear rates was weaker in SC than in LJ systems; morphologies of clusters were occasionally changed to some extent.

Key words: Many-body effect, Colloids, Computer simulation