Manipulating the Morphologies of Cylindrical Polyelectrolyte Brushes by Forming Interpolyelectrolyte Complexes with Oppositely Charged Linear Polyelectrolytes: An AFM Study

作者：Xu Youyong; Borisov Oleg V; Ballauff Matthias; Mueller Axel H E

来源：Langmuir, 2010, 26(10): 6919-6926.

DOI：10.1021/la904167r

We present a study on water-soluble interpolyeleetrolyte complexes (IPECs) formed by cationic cylindrical polyelcctrolyte 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. 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.

• 出版日期2010-5-18