  The adsorption of mixtures of charged polymers onto solid surfaces presents a
big interest in different technological and industrial fields, and in
particular, in cosmetics. This requires to deepen on the most fundamental
physico-chemical bases governing the deposition, which is generally correlated
to the interactions occurring in solution. This work explores the interaction
in solution of model polymer mixtures formed by a cationic homopolymer
(poly(diallyl-dimethyl-ammonium chloride), PDADMAC) and a zwitterionic
copolymer (copolymer of acrylic acid, 3-Trimethylammonium propyl methacrylamide
chloride and acrylamide, Merquat 2003), and the adsorption of such mixtures
onto negatively charged surfaces. The analysis of the interactions occurring in
solution between both polymers performed using dynamic light scattering (DLS),
electrophoretic mobility and viscosity measurements, combined with the study of
the deposition of the layers of mixtures containing different weight fractions
of each polymer using ellipsometry and quartz crystal microbalance with
dissipation monitoring (QCM-D) has shown that the interpolymer complexes formed
in solution, and their composition, governs the deposition onto the solid
surface and the tribological properties of the adsorbed layers as shown the
Surface Force Apparatus (SFA) experiments, allowing for a control of the
physico-chemical properties and structure of the layers. Furthermore, the use
of Self Consistent Mean Fields Calculations (SCF) confirms the picture obtained
from the experimental studies of the adsorbed layers, providing a prediction of
the distribution of the polymer chains within the adsorbed layers. It is
expected that this study can help on the understanding of the correlations
existing between the behavior of future associations of innovative and
eco-sustainable polymers and their adsorption processes onto solid surface.
