A modified langmuir schaefer method for the creation of functional thin films

PhD ceremony: Mr. R. Gengler, 13.15 uur, Academiegebouw, Broerstraat 5, Groningen

Thesis: A modified langmuir schaefer method for the creation of functional thin films

Promotor(s): prof. P. Rudolf

Faculty: Mathematics and Natural Sciences

Low-dimensional assemblies, where order and organization follow supramolecular principles, have shown remarkable importance due to their outstanding physical (photophysical, electrical) and/or chemical (catalysis, molecular separation) properties. An easy method to produce tailored functional materials with excellent level of control combines self-assembly and Langmuir-Schaefer deposition. Regis Gengler illustrates in his thesis how this new approach allows the deposition of graphene on a variety of substrates with a coverage that can be varied as desired from isolated sheets to a densely packed 2D arrangement. In contrast to the currently most common preparation protocols which rely on micromechanical cleavage, the yield of successful deposition of Grenglers approach is 100%, qualifying it as one of today's most trustworthy and promising methods.

Grengler also demonstrates how the same method allows to assemble hybrid materials based on single and/or multi-layers of clay platelets as building blocks. In this case clay nanosheets, deposited similarly to the graphene, act as 2D template for reaction or grafting of a variety of guest species (here C60, Ni8 molecular magnets, Prussian Blue analogues). Perfect layer-by-layer growth and control at the molecular level allow one to create entirely novel architectures whose final structure is encoded in the shape and properties of the clusters or molecules that are used. Interesting new properties emerge: for example 2 or 0D Prussian Blue analogue structures can be formed, which differently from 3D crystals, show new superparamagnetic-spin glass properties with high blocking glass temperature. Finally, Grenglers thesis demonstrates how the preparation method influences the morphology of organoclay assembly.