Polyelectrolyte Multilayers

Published

January 23, 2006

Author(s)

Darwin Reyes-Hernandez, Laurie E. Locascio, Michael Gaitan

Abstract

The process of self-assembly occurs naturally in living systems to form complex structures out of random events in an incredibly accurate way. Order out of disorder is achieved in a fashion that is analogous to a jigsaw puzzle where each piece fits together in a specific configuration by a process that we call molecular recognition. Self-assemblies and template-assisted assemblies have recently become a key approach to nanofabrication for the assembly of nanoarchitectures. In 1992, Decher and co-workers reported on a template assisted assembly technique based on a process that relies on electrostatic interactions between polycations and polyanions to form ultrathin multilayers of polymers, known as polyelectrolyte multilayers (PEMs). This approach takes advantage of the spontaneous self-assembly of a polyelectrolyte on a substrate when immersed in a polyelectrolyte solution. The polyelectrolytes interact electrostatically with the surface adsorbing a polymer monolayer. The substrate is subsequently rinsed with water and immersed in an oppositely charge polyelectrolyte solution until a second layer is adsorbed. Then, the substrate with the two layers of adsorbed polymers is rinsed again with water. These steps can be repeated as many times as polyelectrolyte layers are required. This method is known as layer-by-layer deposition or electrostatic self-assembly. The approach overcomes the limitations encountered in covalent and coordination chemistries in terms of the required proximity of reactive and neighboring groups for the binding to occur.

Citation

Encyclopedia of Biomaterials and Biomedical Engineering

Pub Type

Encyclopedias

Keywords

layer-by-layer deposition, Polyelectrolytes

Citation

Reyes-Hernandez, D. , Locascio, L. and Gaitan, M. (2006), Polyelectrolyte Multilayers, Encyclopedia of Biomaterials and Biomedical Engineering (Accessed April 19, 2024)