Abstract
We report a molecular dynamics simulation investigation of self-assembly and
complex formation of charged-neutral double hydrophilic and hydrophobic-hydrophilic
block copolymers (BCP) with oppositely charged surfactants. The structure of
the surfactant micelles and the BCP aggregation on the micelle surface is
systematically studied for five different BCP volume fractions that also mimics
a reduction of the surfactant concentration. The local electrostatic interactions
between the oppositely charged species encourage the formation of core-shell
structures between the surfactant micelles where the surfactants form the cores
and the charged blocks of the BCP form the corona. The emergent morphologies of
these aggregates are contingent upon the nature of the BCP neutral blocks. The
hydrophilic neutral blocks agglomerate with the micelles as hairy colloidal
structures while the hydrophobic neutrals agglomerate in lamellar structures
with the surfactant micelles. The distribution of counterion charges along the
simulation box show a close-to-normal density distribution for the hydrophilic
neutral blocks and a binodal distribution for hydrophobic neutral blocks. No
specific surfactant concentration dependent scaling relation is observed as
opposed to the simpler case of homo-polyelectrolytes.
