摘要 : Bond fluctuation model and vacancy diffusion algorithm have been used to simulate the phase separation of AB block copolymer and blend in a highly concentrated system.The results are as follows:(i)The mixing is nonrandom even in a... 展开 Bond fluctuation model and vacancy diffusion algorithm have been used to simulate the phase separation of AB block copolymer and blend in a highly concentrated system.The results are as follows:(i)The mixing is nonrandom even in athermal condition where the microscopic interaction energy between A and B monomersε~*=0,so that the assump. tion of random mixing in the mean-field theory is just a rough approximation.(ii)The Flory-Huggins(FH)parameter,X,is just a phenomenological parameter.Therefore,the X value of the block copolymer is higher than that of the corresponding blend although the reduced microscopic molecular interaction energies ε~* are the same.(iii)In the case of the same A,B composition and the same molecular weight of corresponding blocks,the phase separation of AB blend is easier than that of AB block copolymer.Their critical values of the X are:X_c^(blend)=0.1,X_c^(block)=0.41 for the case of chain lengths L_A=10,L_B=11. 收起