Nanomechanische Charakterisierung

Titania based nacre-like hybrid films. a) Polarized light microscope image of cross-sectional
Red Abalone shell specimen. The inset shows an AFM image acquired within the nacre part. 
b) HRTEM image of, cross-section.

During the past few years, our group has gathered strong expertise on the synthesis and characterization of bioinspired, nanostructured composite films with an alternating layer rchitecture that combines a soft, organic component (polyelectrolyte (PE), or the protein hydrophobin) with a robust, inorganic material (e.g., TiO2, ZnO, or ZrO2). These composites have been obtained via chemical bath deposition of the inorganic component, combined with layer-by-layer (LBL) deposition of the organic component. By controlling the thickness of the organic component, we have been able to obtain films closely mimicking their natural counterparts (e.g., nacre). Furthermore, the alternating layer structure has been observed to notably enhance the mechanical performance in comparison to the pure oxide films. In particular, this involves a strong enhancement of fracture toughness, combined with a moderate increase in hardness and preservation of the Young’s modulus of the major component. Through microscopic analysis, several factors could be identified that are responsible for this enhancement, most prominently the efficient distribution of externally applied stress along the organic-inorganic interface. The promising mechanical properties of thus obtained nanostructured films demonstrate the strong potential of this bioinspired synthesis approach. In particular, it allows fine-tuning the thickness ratio of the soft and hard layers, as well as to tailor their interface for example through template-directed nucleation.

 

Projects:

DFG BI469/17-1
Synthese und Charakterisierung von papier-artigen, nanostrukturierten Elektroden für Sekundärbatterien

Literature:

Santhiya, D., Burghard, Z., Greiner, C., Jeurgens, L.P.H., Subkowski, T., Bill, J., 2010. Bioinspired Deposition of TiO2 Thin Films Induced by Hydrophobins. Langmuir 26, 6494-6502.

Zlotnikov, I., Gotman, I., Burghard, Z., Bill, J., Gutmanas, E.Y., 2010. Synthesis and mechanical behavior of bioinspired ZrO2-organic nacre-like laminar nanocomposites. Colloid Surface A 361, 138-142.

Burghard, Z., Zini, L., Srot, V., Bellina, P., van Aken, P.A., Bill, J., 2009. Toughening through Nature-Adapted Nanoscale Design. Nano Letters 9, 4103-4108.

Burghard, Z., Tucic, A., Jeurgens, L.R.H., Hoffmann, R.C., Bill, J., Aldinger, F., 2007. Nanomechanical properties of bioinspired organic-inorganic composite films. Advanced Materials 19, 970-+.

Lipowsky, P., Burghard, Z., Jeurgens, L.P.H., Bill, J., Aldinger, F., 2007. Laminates of zinc oxide and poly( amino acid) layers with enhanced mechanical performance. Nanotechnology 18, -.