通过与带相反电荷的线性聚合物形成聚电解质复合物来操纵圆柱形聚电解质刷的形态：原子力显微镜研究。

Manipulating the morphologies of cylindrical polyelectrolyte brushes by forming interpolyelectrolyte complexes with oppositely charged linear polyelectrolytes: an AFM study.

机构信息

Makromolekulare Chemie II, and Bayreuther Zentrum für Kolloide und Grenzflächen, Universität Bayreuth, D-95440 Bayreuth, Germany.

出版信息

Langmuir. 2010 May 18;26(10):6919-26. doi: 10.1021/la904167r.

DOI:10.1021/la904167r

PMID:20229989

Abstract

We present a study on water-soluble interpolyelectrolyte complexes (IPECs) formed by cationic cylindrical polyelectrolyte brushes (CPBs) and linear anionic poly(sodium styrenesulfonate) (PSSNa) using atomic force microscopy (AFM). The IPECs were prepared by dialysis of salt-containing solutions of the two polymeric components. The morphologies of the IPECs could be tuned by changing the charge ratio between the two polyelectrolytes, Z(-/+). Addition of increasing numbers of short PSSNa chains induced morphology changes of host CPBs from worms through intermediate pearl-necklace structures to fully collapsed spheres. Extremely long guest PSSNa caused the full collapse of the brushes to spheres even at very low charge ratios without intermediate states. In both cases we observe "disproportionation", that is, inhomogeneous distribution of the PSS chains between the CPB for Z(-/+) < 1. Unexpected micrometer-scale core-shell cylindrical objects were found by directly mixing CPBs with long PSSNa, which might be nonequilibrium structures caused by the kinetically controlled IPEC formation.

摘要

我们使用原子力显微镜（AFM）研究了阳离子圆柱状聚电解质刷（CPB）和线性阴离子聚（苯乙烯磺酸钠）（PSSNa）形成的水溶性聚电解质复合物（IPEC）。通过含有两种聚合物组分的盐溶液透析制备 IPEC。通过改变两种聚电解质之间的电荷比 Z(-/+)，可以调节 IPEC 的形态。加入越来越多的短 PSSNa 链会引起主体 CPB 的形态变化，从蠕虫状通过中间的珍珠项链结构到完全塌陷的球体。即使在电荷比非常低的情况下，非常长的 PSSNa 也会导致刷子完全塌陷成球体，而没有中间状态。在这两种情况下，我们都观察到了“歧化”，即 PSS 链在 CPB 之间的不均匀分布，对于 Z(-/+) < 1。通过直接混合 CPB 和长 PSSNa，我们发现了意想不到的微米级核壳圆柱形物体，这可能是由动力学控制的 IPEC 形成引起的非平衡结构。