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.

Illustrations

Production of thin film using the layer assembly technique: A — deposition of negative polyelectr

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

  1. Golosova A. Thin polymer films based on multilayer assemblies (in Russian) // Nanoindustrija. 2007. №4. P. 34–36.

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