Langmuir–Blodgett method (rus. Ленгмюра–Блоджетт, технология otherwise пленки Ленгмюра–Блоджетт; метод Ленгмюра–Блоджетт abbr., LB) — a technology of producing mono-and multimolecular films by transferring Langmuir films (monolayer of amphiphilic compounds formed on the surface of a liquid) to the surface of a solid substrate.
The method of forming mono-and multimolecular films was developed by Irving Langmuir and his assistant Katharina Blodgett in 1930s. Currently, this technology, named the Langmuir-Blodgett method, is widely used in the production of electronic equipment.
The main idea of the method is to form a monomolecular layer of an amphiphilic substance on the water surface and then transfer it to a solid substrate. In the aqueous phase the amphiphilic substance molecules are arranged on the air-water interface. To form a monomolecular surface layer the surface layer is compressed using a special barrier (see Fig. 1). The sequential isothermal compression changes the structure of the monomolecular film, which passes through a series of two-dimensional states, conventionally referred to as gas, liquid crystal and solid crystal (see Fig. 2). Thus, knowing the phase diagram of the film one can control its structure and associated physico-chemical properties. To transfer the film to a solid support, a flat substrate is immersed in the solution and then extracted with the surface film adsorbed on it. The process of monomolecular film transfer can be repeated many times to obtain various multimolecular layers.
Fig. 1. Schematic diagram of Langmuir-Blodgett films making.
Fig. 2. Condition of Langmuir-Blodgett film depending on the surface pressure.
Streletskiy Alexey V.
Langmuir–Blodgett film //Wikipedia, the free Encyclopedia. — http://en.wikipedia.org/wiki/Langmuir%E2%80%93Blodgett_film (reference date 12.12.11).
self-assembled monolayers