摘要
运用 Monte Carlo方法对线型高分子链格点模型的构型进行了模拟 ,研究了构型的尺寸 (采用平方末端距 R2 ,平方回转半径 S2来表征 )和形状 (由非球形因子 A表征 )之间的关联 .对任何长度的高分子链 ,其关联系数 CA,R2 和 CA,S2 均为正值 ,表明高分子链的形状与尺寸之间存在正关联 ,即尺寸小的构型其非球形因子 A一般也小 ,反之尺寸大的构型其非球形因子 A一般也大 .关联系数 CA,R2 和 CA,S2 均随链长的增大而减小 ,近似地与链长的倒数 ( n- 1 )成正比 .研究还表明 ,关联系数的极限值 (链长 n很大时 )与格点的类型无关 ,与链样本产生的方式也无关 ,但与链是否考虑排斥体积有关 ,考虑了排斥体积后 ,关联系数增大 .
The configurations of linear lattice polymer chain model were simulated by using Monte Carlo method. The correlation between chain size(measured by the square end-to-end distance R 2 and the square radius of gyration S 2) and shape(measured by the asphericity parameter A) was studied. A positive correlation is found for any chain length, indicating that a chain configuration of small size is usually more spherical than that of a large one, vice versa. The correlation coefficients C A,R 2 and C A,S 2 decrease with the increase of chain length, approximately in proportional to the reciprocal of chain length n -1. The results show that the limits of C A,R 2 and C A,S 2 at a large chain length are independent of the lattice model and chain sampling method, but they become large when the excluded volume among chain segments is considered.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2002年第11期2172-2176,共5页
Chemical Journal of Chinese Universities
基金
浙江省自然科学基金 (批准号 :10 0 0 35 )资助
