A kind of semi-rigid main-chain polyelectrolyte

poly(p-xylylene-4

4'-bipyridinium dibromide) (PXV) was synthesized by Menshutkin reaction

then a series of novel polyelectrolyte-surfactant (PXV-Cn) complexes were produced by electrostatic self-assembly through stoichiometric mixing of PXV with various anionic surfactants of sodium aliphatate (Cn-1COONa

n= 10

12

14

16

18).The supramolecular structure and mesomorphic phase behavior of thus assembled PXV-Cn complexes were preliminarily investigated by DSC

TGA

XRD

and FTIR.Based on the FTIR spectroscopic evidence

variant temperature XRD data and thermal analysis enthalpic quantitative calculation

a lamellar mesomorphic supramolecular structure was suggested with the polar head groups of the aliphatate surfactants and the polyelectrolyte PXV composing the polar layer while the alkyl side chains constructing the apolar layer.Furthermore

it was found that the alkyl side chains in the PXV-Cn complexes formed an end-to-end bilayer structure with about eight methylene groups near the head group in the amorphous state and others in the crystalline structure.Among them PXV-C10 with the shortest surfactant alkyl group only possessed the least ordered triclinic crystal phase T

while the most ordered hexagonal crystal H dominated in those complexes with n16

and variant crystalline polymorphs coexisted in those with intermediate n=12 or 14. The melting points Tm increased with increasing n

the complexes with longer alkyl chains of n16 exhibited almost reversible crystalline phase changes in the heating-cooling thermal cycles.This kind of polyviologen-surfactant complexes also showed better thermal stability without any remarkable weight loss below 200℃.The employment of the polyelectrolyte-polyviologen possessing redox properties made it a promising functional polyelectrolyte-surfactant complex for electrochromism and photochromism applications.