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Ultra Thin Film LaboratoryC. Bubeck |
References Keywords Cross-links to other projects Hardware |
The processing of polymers to thin films
is a prerequisite for many fundamental studies and technological applications
of polymers. Specific layer thicknesses are required in the typical range
between a monolayer and several mm depending on the intended purpose such
as thin film waveguides, surface coatings and modifications, supramolecular
architectures, model membranes, model surfaces, and layer systems with
planned functionalities. The thin film laboratory comprises many different
techniques for the cleaning and pretreatment of substrates and the preparation
of organic and inorganic thin films:
Mono- and multilayers are prepared by adsorption and chemisorption processes and by the Langmuir-Blodgett technique. The latter is used to transfer insoluble monolayers – layer by layer – from the air/water interface to solid substrates as visualized below.
Spin-coating is a frequently used preparation method for thin films of polymers. Films with controlled thickness and minimized surface roughness can be obtained by careful optimization of parameters like molecular weight, solvent, concentration, angular frequency of the rotating substrate and temperature. Polymer films thicker than approximately 5 mm can be prepared by means of the doctor-blading technique.
Thermal evaporation of inorganic materials (e.g. metals, semiconductors or dielectrics) is used for the preparation of special substrate surfaces, deposition of electrodes or for surface decoration. The composition and the state of order of the organic surface has decisive influence on the sticking probability, nucleation and island growth of the incident atoms. On the other hand the island formation can be used as versatile decoration method to visualize textures of ultrathin organic films.
Mono- and multilayers are prepared by adsorption and chemisorption processes and by the Langmuir-Blodgett technique. The latter is used to transfer insoluble monolayers – layer by layer – from the air/water interface to solid substrates as visualized below.
Spin-coating is a frequently used preparation method for thin films of polymers. Films with controlled thickness and minimized surface roughness can be obtained by careful optimization of parameters like molecular weight, solvent, concentration, angular frequency of the rotating substrate and temperature. Polymer films thicker than approximately 5 mm can be prepared by means of the doctor-blading technique.
Thermal evaporation of inorganic materials (e.g. metals, semiconductors or dielectrics) is used for the preparation of special substrate surfaces, deposition of electrodes or for surface decoration. The composition and the state of order of the organic surface has decisive influence on the sticking probability, nucleation and island growth of the incident atoms. On the other hand the island formation can be used as versatile decoration method to visualize textures of ultrathin organic films.
| Principle of the Langmuir-Blodgett technique: Spreading of amphiphiles at the air/water interface and transfer of condensed monolayers to solid substrates | |
| Nucleation behaviour of metal films on organic model surfaces: Schematic side view of metal islands on an organic double layer |
References:
Cross-links to other projects: Hardware:
- C. Bubeck, „Imaging of the lateral structure of Langmuir-Blodgett films by metal decoration and polarization microscopy“, Thin Solid Films 210/211 98-102 (1992)
- F. Fitrilawati, M.O. Tjia, J. Ziegler, C. Bubeck, ”Fabrication of planar waveguides of poly(N-vinylcarbazole)”, Proc. SPIE 3896 (1999, Dec. Issue) in press.
- Langmuir-Blodgett
- Spin-coating
- Monolayer
- Surface texture
- Surface roughness
- Metal/polymer interfaces
Cross-links to other projects: Hardware:
- 4 Bleymehl laminar-flow benches
- Langmuir troughs from Lauda and KSV
- Headway spincoater
- Erichsen
