接枝点分布对ABA三嵌段共聚物刷自组装形态的影响  

Influence of Grafting Point Distribution on Self-assembly Morphology of ABA Triblock Copolymer Brush

作　　者：徐纪华 陈印启 尹玉华[2] 蒋润[2] 王铮[2] 李宝会[2] Ji-hua Xu;Yin-qi Chen;Yu-hua Yin;Run Jiang;Zheng Wang;Bao-hui Li(School of Physics and Electronics,Shandong Normal University,Jinan 250358;School of Physics,Nankai University,Tianjin 300071)

机构地区：[1]山东师范大学物理与电子科学学院,济南250358 [2]南开大学物理科学学院,天津300071

出　　处：《高分子学报》2020年第6期632-640,I0005,共10页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号11504208,21674053)资助项目。

摘　　要：采用模拟退火方法研究了接枝点分布对ABA三嵌段共聚物刷在选择性溶剂中自组装形态的影响,其中溶剂对A单体为不良溶剂,对B单体为良溶剂.主要以高接枝密度体系为例,研究了均匀接枝、区域随机接枝和全随机接枝时共聚物刷聚集体的形态,分别构建了3种接枝方式下体系的相图,并考察了接枝点分布对ABA三嵌段共聚物刷形态的影响机制.研究表明3种接枝方式下,ABA三嵌段共聚物刷体系形成相图大致相同,并且单层A聚集体结构与双层A聚集体结构在相图中的分界线相同;接枝点分布主要对底部的A富集层胶束形态产生影响,而对顶层胶束形态影响很小.在随机接枝时,接枝点的密度涨落导致底层A聚集体不易形成较规则的形态,其长程有序性较低.The simulated annealing method was used to study the self-assembly morphology of the symmetrical ABA triblock copolymer brush formed with one end of the A-blocks tethered onto a planar surface.The copolymer brush was immersed in a selective solvent which is poor for the A-blocks but good for the middle Bblocks.Taking the system at high grafting density as an example,the morphology of the copolymer brush aggregates during uniformal grafting,local random grafting and global random grafting were investigated,and the phase diagram was constructed.The simulation studies showed that the position distribution of the grafting point mainly affect the morphology of aggregates near the bottom layer for ABA triblock copolymer brushes.A similar self-assembled morphology could be formed during uniformal grafting,region random grafting,and global random grafting.However,the density fluctuation of the grafting point caused the micelle morphology formed under random grafting,which did not have the regular shape as that formed under uniformal grafting,and the long-range order in the microphase-segregated structures is reduced.The self-assembled morphologies of homopolymer brushes in poor solvent and AB diblock copolymer brushes in the solvent which is selective for the tethered A-blocks but poor for the top B-blocks were also investigated to further understand the results mentioned above.

关 键 词：三嵌段共聚物刷 模拟退火 自组装 接枝点 

分 类 号：TQ317[化学工程—高聚物工业]