Coatings and thin films made from nanoparticles (NPs) have gained recognition and use in various products and applications including displays, sensors, medical devices, energy storage devices, and energy harvesting. Synthesis methods for nanoparticles [1] are already relatively well known, but to be able to utilize them in the applications mentioned above, NPs need to be transferred from the solution phase to a substrate’s surface – often as a monolayer or defined thickness multilayer. For this, controlled deposition methods are required. Langmuir-Blodgett and Langmuir-Schaefer provide a highly controlled method for nanoparticle monolayers at the air-liquid interface and their subsequent transfer onto a solid substrate. These methods can form high-density (poly-crystalline) monolayers on a wide variety of solid substrates, including conventionally challenging non-flat surfaces.
Techniques that enable such control and precision during thin film formation are critically important in the development of new nanoparticle-based materials. The Langmuir-Blodgett (LB) deposition method offers a combination of controlled deposition, a wide range of substrates, and usability in ambient conditions. In an LB deposition process, a nanoparticle suspension is first deposited at the air/water interface, then, the resulting film is compressed to the desired surface pressure and particle density and then transferred onto a solid substrate by dipping the substrate into and through the particle layer. The deposition can then be repeated to fabricate alternating layer structures or performed at different speeds and temperatures.
As a summary, with LB and LS methods, it is possible to:
Susanna is an Application Scientist at Biolin Scientific. In her PhD thesis, she developed fabrication methods for a new type of inorganic-organic polymers. Microfabricated polymer chips were utilized as tool for biomolecule separation in analytical chemistry.
