Abstract
Self-assembly and dynamics of polyelectrolyte (PE) surfactant complex (PES)
is investigated using molecular dynamics simulations. The complexation
is systematically studied for five different PE backbone charge densities.
At a fixed surfactant concentration the PES complexation exhibits pearl-necklace
to agglomerated double spherical structures with a PE chain decorating the
surfactant micelles. The counterions do not condense on the complex, but are
released in the medium with a random distribution. The relaxation dynamics for
three different length scales, polymer chain, segmental and monomer, show
distinct features of the charge and neutral species; the counterions are fastest
followed by the PE chain and surfactants. The surfactant heads and tails have
the slowest relaxation due to their restricted movement inside the agglomerated
structure. At the shortest length scale, all the charge and neutral species show
similar relaxation dynamics confirming Rouse behavior at monomer length scales.
Overall, the present study highlights the structure-property relationship for
polymer-surfactant complexation. These results will help improve the understanding
of PES complex and should aid in the design of better materials for future applications.