聚苯乙烯-聚丙烯酸嵌段共聚物胶束在临界温度下的有规聚集

Regular Aggregation of Polystrene-b-Poly(acrylic acid) Micelles at Critical Temperature

用扫描电子显微镜对聚苯乙烯 b 聚丙烯酸 (PS b PAA)嵌段共聚物在水中自组装形貌进行了观察。结果表明 :外界环境和制样方法能够影响聚合物的自组装和聚集情况。 0℃时 ,PS38 b PAA2 10 胶束聚集形成纺锤状结构。而在临界条件下 ,缓慢改变体系冷冻 解冻循环次数 ,则会得到这些纺锤结构的花状聚集体。

Needle-like micelle of PS 38-b-PAA 210 is formed at 0℃, whose average diameter is about 60 nm and length is 1.5 μm after the introduction of an outside driving force regular aggregation of the micelles emerges. They aggregated into long-range, close-packed, finger-like structure. This ordered structure originates from the low solubility of the micelles, hydrogen bonding, which is formed between the PAA part of different polymer needle, and the orientation stress given by H 2O molecules at a critical temperature.