Adsorption of Polyelectrolytes onto Charged Surfaces 65the different parameter that allows tuning the multilayer growth: pH, ionic
strength, T, etc. This is in good agreement with the computer simulation by
Cohen-Stuart [42]. On the other side τ 2 can present complex dependence on N,
providing information of the appearance of interdiffusion processes. This
reorganization time, τ 2 , give information of the reorganization of the adsorbed
polymer on the adsorption plane in those case in which there is no dependence
on N, e.g., (PAH + PSS)n. On the other side, if there is an increase of τ 2 with
N, it is possible to assume the existence of three-dimensional reorganization of
the adsorbed material together to that occurring along the adsorption plane,
and consequently the existence of interdiffusion, e.g., (PDADMAC + PSS)n.
The existence of different levels for the reorganization of the adsorbed
material can be explained on the bases of the model proposed by Lane
et al. [114] for multilayers formed by PSS and poly[1-[4[(3-carboxy- 4 -
hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl sodium salt]. This
model is schematized in Figure 14 with the corresponding relationship
between the mechanism and the corresponding adsorption time.
Reprinted with permission from Reference [30] Copyright (2012) American Chemical
Society.
Figure 14. Illustration of the different processes involved in the adsorption of
polyelectrolyte multilayers.