The complex formation in the oppositely charged linear and
flexible polyelectrolytes:
quaternized poly(vinylpyridinium) (QPVP) and poly(sodium
styrenesulfonate) (NaPSS) was investigated
by static and dynamic light scattering (LS), flow birefringence (FB),
and viscometry over a wide range of
mixing ratios 0.003 ≤ m ≤ 0.9. NaPPS/QPVP systems in
N-methylformamide + 0.01 M KBr generated
complexes with fractal geometries. The observed clusters were
stable and had average dimensions R
g
≈
R
h ≈ 1000 Å at low and high mixing ratios.
As the mixing ratio approached m = 0.4, which
corresponds
to the gel point, the number and the dimensions of clusters grew to
R ≈ 1500−3000 Å with a corresponding
increase of the fractal parameter d ≈ 3. According to
FB data, the axial ratio of the clusters at the gel
point m = 0.4 was p =
L/d = 1.07, which supports a model with
spherical shape.