嵌段序列对ABC三元共聚物在选择性溶剂中自组装的影响。

Effect of block sequence on the self-assembly of ABC terpolymers in selective solvent.

作者信息

Zhang Yi, Lin Wencheng, Jing Rongkuan, Huang Junlian

机构信息

The Key Laboratory of Molecular Engineering of Polymer, State Education Ministry of China, Department of Macromolecular Science, Fudan University, Shanghai 200433, China.

出版信息

J Phys Chem B. 2008 Dec 25;112(51):16455-60.

PMID:19367812

Abstract

The effect of block sequence on the self-assembly of ABC terpolymers in selective solvent (water/THF) was explored based on two kinds of terpolymers: polystyrene-block-poly(ethylene oxide)-block-poly(acrylic acid) (PS-b-PEO-b-PAA) and PEO-b-PS-b-PAA with the same component, comparable molecular weight, but different block sequence. Copolymer PS-b-PEO-b-PAA has a higher critical water content (CWC) and larger aggregates size than PEO-b-PS-b-PAA. Furthermore, they presented vesicles with hundreds of nanometers at 25% water content which was not observed in the case of PEO-b-PS-b-PAA. It was also found that there was a sharp jump of both the scattering light intensity and average aggregate size for PS-b-PEO-b-PAA. The kinetics of morphological transitions vs the water content was described to explain this phenomenon.

摘要

基于两种具有相同组分、相近分子量但嵌段顺序不同的三元共聚物：聚苯乙烯-嵌段-聚环氧乙烷-嵌段-聚丙烯酸（PS-b-PEO-b-PAA）和PEO-b-PS-b-PAA，研究了嵌段顺序对ABC三元共聚物在选择性溶剂（水/四氢呋喃）中自组装的影响。与PEO-b-PS-b-PAA相比，共聚物PS-b-PEO-b-PAA具有更高的临界水含量（CWC）和更大的聚集体尺寸。此外，在水含量为25%时，它们呈现出数百纳米的囊泡，而PEO-b-PS-b-PAA则未观察到这种情况。还发现PS-b-PEO-b-PAA的散射光强度和平均聚集体尺寸都有急剧跃升。描述了形态转变动力学与水含量的关系以解释这一现象。