Adsorption of anionic polyelectrolytes to dioctadecyldimethylammonium bromide monolayers

Abstract

Monolayers of dioctadecyldimethylammonium bromide (DODA) at the air/water interface were used as model for charged surfaces to study the adsorption of anionic polyelectrolytes. After spreading on a pure water surface the monolayers were compressed and subsequently transferred onto a polyelectrolyte solution employing the Fromherz technique. The polyelectrolyte adsorption was monitored by recording the changes in surface pressure at constant area. For poly(styrene sulfonate) and carboxymethylcellulose the plot of the surface pressure as function of time gave curves which indicate a direct correlation between the adsorbed amount and surface pressure as well as a solely diffusion controlled process. In the case of rigid rod-like poly(p-phenylene sulfonate)s the situation is more complicated. Plotting the surface pressure as function of time results in a curve with sigmoidal shape, characterized by an induction period. The induction period can be explained by a domain formation, which can be treated like a crystallization process. Employing the Avrami expression developed for polymer crystallization, the change in the surface pressure upon adsorption of rigid rod-like poly(p-phenylene sulfonate)s can be described.

Study of the growth process of in situ polyaniline deposited films

“…The experimental results [33][34][35][36] were fitted using the Johnson-Mehl-Avrami equation (JMA), given by…”

Lipid Monolayers with Adsorbed Oppositely Charged Polyelectrolytes: Influence of Reduced Charge Densities

“…However, a reduction of π c with the molecular weight of PSS has been observed. It cannot be attributed to electrostatic forces as described by the DLVO theory [18,19]. π c decreases on increase of the molecular weight, until the contour length corresponds to the persistence length, then π c is independent of the molecular weight.…”

“…Simultaneously, the surface charge density of the monolayer increases by a factor of two. The adsorbed PEs influence the interactions between the lipid molecules, which can best be investigated by exploring the LE/LC phase transition [18][19][20] PEs in salt-free solution have a much larger persistence length than neutral polymers [21]. If the contour length L K is smaller than the persistence length L P (L K  L P ) then the polymer is approximated as an elastic rod.…”

Formation of complex Langmuir and Langmuir–Blodgett films of water soluble rosebengal

“…Recently, it has been observed that some water-soluble materials can also form stable and well-organized Langmuir monolayer at the air-water interface [4][5][6][7]. It was first observed by Vollhardt et al in 1997 [8] and later discussed in detail in another two papers [9,10].…”

“…Menzel et al reported the reaction kinetics and adsorption of poly(styrene sulfonate) and carboxymethylcellulose sodium salt onto a preformed dioctadecyldimethylammonium bromide monolayer [6,7]. Adsorption of poly(NIPAM) on the preformed pentadecanoic acid (PDA) monolayer was demonstrated by Kawaguchi et al [5].…”