Application

Langmuir and Langmuir-Blodgett are used in several fields, where liquid thin films are studied (Langmuir films) and/or transferred to solid substrates in one or more well-organized layers (Langmuir-Blodgett films) Although the technique is traditional, its use is growing in new areas, such as

• Functional coatings with nanoparticles, with design of specific surface properties such as optical reflectivity, biocompatibility, wettability, conductivity, adhesion, etc.
• Cell membrane model systems, where the structural and functional effects of toxins or drugs on lipid bilayers can be studied.
• Films of new biopolymers can be studied for crosslinking, stability, degradation, etc.
• Study of proteins, lipids and other amphiphilic molecules, where adsorption, stability, structure and interaction are often important properties.
• In combination with Interfacial rheology, determination of film stability, phase transitions and reactions

Langmuir-Blodgett has a number of advantages over other coating techniques:

• Precise control over packing density
• Precise control of film thickness
• Homogeneous coating over large areas
• The system works in a normal room environment
• Multi-layer with varying layer structure can be created
• Flexibility in the choice of particles/molecules and substrates
• The film quality, packing density and packing pattern can be optically checked before transfer to substrates.

Flexibility

An open and modular design allows you to inspect and characterize your film both during creation and before transfer to substrates.
You can use multiple tray sizes and tray types for one frame, with locating pins it’s super easy to change trays with perfect positioning.
With the largest range of tray sizes, tray types and characterization accessories on the market, we are happy to help you find exactly the configuration that fits your needs.

Quality

The troughs, including the well for LB, are made from a single piece of PTFE, which facilitates cleaning (which is essential for L & LB!) and eliminates the risk of contamination from glues and coatings.
For safe and high-quality use, the systems come with:

• Adjustable legs – no matter where you place the tray, you can create a horizontal surface.
• Tray positioning locator pin – whichever of the interchangeable trays you use, it will always be mounted in the correct position in the frame.
• Barrier limit switches – no need to worry about breaking the barrier, damaging the motor or other parts of the system.
• Flood channel – any liquid that spills over the edge of your trough does not end up on the lab bench, but is captured by an external channel, which runs around the entire trough.
• Thermostatic troughs for constant and relevant temperature.

Ease of use and support

Biolin Scientific Langmuir and Langmuir-Blodgett measure surface tension/surface pressure using the wave-based Wilhelmy method, where you can choose to use paper Wilhelmy plates (disposable) to avoid cleaning and contamination risk.
KSV NIMA software contains all the functions to control and analyze, including the different characterization modules.

Technology

Langmuir (L) and Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) can create and analyze films as thin as a molecular layer with full control over packing density.
This is done by spreading molecules on a liquid surface (usually, but not exclusively, aqueous phase) and then compressing the surface with moving barriers.
The barriers are brought together until the molecules, which are initially so far apart that they can be compared to the gas phase, pass through the liquid phase until they are so densely packed that they can be considered a liquid two-dimensional solid.
While this is being done, surface pressure is measured and the process can be followed by an isotherm where surface pressure is plotted against specific surface area (how much surface area each molecule occupies). In addition to reading in an isotherm when maximum packing density has been reached, it is also possible to simultaneously follow the process visually using a MicroBAM (Brewster Angle Microscope).
Transfer to a vertically immersed substrate (Langmuir-Blodgett) or a horizontally dipped substrate (Langmuir-Schaefer) then takes place with great precision while the barriers are active and keep the packing density constant.
In this way, very homogeneous and perfect molecular films can be transferred.
The process can be repeated several times with the same or different molecules/particles and thus multilayers can be created with great control of packing density and film thickness.