Deposition Mechanisms in Layer-by-Layer or Step-by-Step Deposition Methods: From Elastic and Impermeable Films to Soft Membranes with Ion Exchange Properties

Abstract

The modification of solid-liquid interfaces with polyelectrolyte multilayer films appears as a versatile tool to confer new functionalities to surfaces in environmentally friendly conditions. Indeed such films are deposited by alternate dipping of the substrates in aqueous solutions containing the interacting species or spraying these solutions on the surface of the substrate. Spin coating is more and more used to produce similar films. The aim of this short review article is to provide an unifying picture about the deposition mechanisms of polyelectrolyte multilayer films. Often those films are described as growing either in a linear or in a supralinear growth regime with the number of deposited "layer pairs". The growth regime of PEM films can be controlled by operational parameters like the temperature or the ionic strength of the used solutions. The control over the growth regime of the films as a function of the number of deposition steps allows to control their functional properties: either hard and impermeable films in the case of linear growth or soft and permeable films in the case of supralinear growth. Such different properties can be obtained with a given combination of interacting species by changing the operational parameters during the film deposition.

Comparison of permeability of poly(allylamine hydrochloride)/and poly(diallyldimethylammonium chloride)/poly(4-styrenesulfonate) multilayer films: Linear vs. exponential growth

“…Similar studies of the permeability and mechanical properties of multilayers composed from polyelectrolytes and montmorillonite clay were investigated by Ball et al [46] and Elzbieciak et al [47]. The differences in permeability of linearly and exponentially growing polyelectrolyte films were discussed by Michel et al [48], but without quantifying them. Zahn et al [49] used cyclic voltammetry to show that the polyelectrolyte interdiffusion has a strong influence on the speed of electron transport in redox-active polyelectrolyte multilayers, i.e., films exhibiting exponential growth allow for faster electron transport.…”

Fabrication and Characterization of Hollow Microcapsules from Polyelectrolytes Bearing Thymine Pendant Groups for Ultraviolet‐B (UVB)‐Induced Crosslinking

“…Finally, π‐staking interactions between the aromatic ring benzyl moieties of both P 4+ and P 4− chains can also contribute to the formation and stabilization of the multilayered shell. Consequently, the VBT‐based polyelectrolytes offer multiple type of interactions conducting to self‐assembly formation …”

Spectroscopic Characterization of Niagara Blue Dye in the Restricted Geometry of Layer-by-Layer Self-Assembled Films

“…This result is consistent with the reports published. 30,[36][37][38] 3.6. LbL¯lms of NB with surfactant (DDAB) Figure 8 shows the fabrication of LbL self-assembled DDAB-NB¯lms at di®erent surfactant concentrations (10 À3 -10 À5 M) at constant NB concentration of 10 À3 M. Here, the dipping time for both the PAH and NB solution was kept at 15 min and the same protocol was followed as in case of PAH-NB¯lms.…”