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Plasma activation of polyetheretherketone (PEEK) surfaces and the influence on coating formation in a supersaturated calcium phosphate solution was investigated in this study. It was observed that plasma treatment in a N2/O2 plasma had a significant effect on the wettability of the PEEK surface. The contact angle decreased from 85 degrees to 25 degrees after plasma treatment. Cell culture testing with osteoblastic cell lines showed plasma activation not to be disadvantageous to cell viability. X-ray photoelectron spectroscopy (XPS) analysis was performed to characterize the chemical composition of the PEEK surfaces. It was observed that the O1s intensity increased with plasma activation time. At the C1s peak the appearance of a shoulder at higher binding energies was observed. Coating of PEEK was performed in a supersaturated calcium phosphate solution. Coating thicknesses of up to 50 microm were achieved after 24 days of immersion. Plasma activation followed by nucleation in a highly saturated hydroxyapatite solution had a positive effect on the growth rate of the layer on PEEK. Chemical analysis revealed that the coating consists of a carbonate-containing calcium phosphate.

Microstructured honeycomb catalysts made of rhodium were manufactured and tested in the partial oxidation of methane under different experimental conditions. Even at operating pressures of up to 1.2 MPa with oxygen and up to 2.0 MPa with air, the catalyst was not found to be adversely affected by the reaction heat caused by the total oxidation taking place at the catalyst inlet. The high thermal conductivity of rhodium contributes to a good heat distribution in the flow direction, which is reflected by significantly increased conversions and CO and H 2 selectivities compared to those obtained by using a stack of commercial Pt/Rh gauzes. Increasing catalyst temperatures lead to an increase in the syngas yield. However, the thermodynamic equilibrium of the reaction was not reached in the experiments. Deactivitation of the catalyst was not observed during experimental operation.

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