【摘要】 在自洽平均场中计算聚合物宏观相分离体系时,需要将正则系综与巨正则系综结合使用。通过将正则系综与巨正则系综之间的变量进行转化,只在正则系综下计算即可得到巨正则系综下的相应变量的值,在很大程度上减少了计算量。本文利用这种简化方法计算了A-b-B两嵌段共聚物与均聚物A在不同均聚物聚合度下随着均聚物含量变化的相图,其结果与巨正则系综下的计算结果相同。该结果表明,在嵌段共聚物与均聚物的共混体系中,增加嵌段共聚物组成fA或者减小均聚物的聚合度,将有效阻止体系发生宏观相分离。更多还原

【Abstract】 For the self-consistent field theory( SCFT) simulation of the phase diagrams of copolymer blends, the grand canonical ensemble and canonical ensemble need to be combined in the simulation. Through converting the variables between grand canonical ensemble and canonical ensemble,we can calculate the variables of grand canonical ensemble directly from canonical ensemble,which simplify the calculation. Here the method was applied to calculate the phase diagram of diblock copolymer( A-b-B) / homopolymer( A) blends with different molecular masses. It was found that the macrophase separation is prevented in the blends by increasing the volume fraction, fAof the block copolymer or decreasing the molecular mass of the homopolymer.更多还原