layer-by-layer
(rus. послойная сборка)
—
method for producing multilayer thin film structures based on sequential deposition of monolayers from polymer solution onto a substrate.
Description
The assembly process proceeds as follows. A well purified solid base is immersed in a dilute solution of a negatively charged polyelectrolyte for the time optimal for the adsorption of one monolayer, then washed and dried. As the next step, the plate, with a negatively charged layer, is immersed into positively charged polyelectrolyte solution for the time required for the adsorption of a monolayer. The plate is again washed and dried. Thus, a sandwich bilayer is created. Repeating these steps many times, a film with the desired thickness is obtained.
Initially it was thought possible to create multilayer assemblies only by electrostatic interaction of water-soluble compounds. Recently, however, the possibility was found to obtain films from organo-soluble polymers. In this case, the films are stabilised by hydrogen bonds and hydrophobic interactions.
Layer-by-layer assembly produces thin films (5-500 nm) of a given thickness and composition from a large variety of systems, and assembly can be performed on any charged surface. The apparent advantage of the method is the simplicity of the technology: the process can be carried out at room temperature in the open air.
Initially it was thought possible to create multilayer assemblies only by electrostatic interaction of water-soluble compounds. Recently, however, the possibility was found to obtain films from organo-soluble polymers. In this case, the films are stabilised by hydrogen bonds and hydrophobic interactions.
Layer-by-layer assembly produces thin films (5-500 nm) of a given thickness and composition from a large variety of systems, and assembly can be performed on any charged surface. The apparent advantage of the method is the simplicity of the technology: the process can be carried out at room temperature in the open air.
Illustrations
Production of thin film using the layer assembly technique: A — deposition of negative polyelectrolyte (polyanion); B — deposition of positive polyelectrolyte (polycation). |
Author
- Zaitsev Dmitry D.
Source
- Golosova A. Thin polymer films based on multilayer assemblies (in Russian) // Nanoindustrija. 2007. №4. P. 34–36.