Yves Martelé

Controlled patterning of biomolecules on solid surfaces

Abstract The micropatterning of different enzymes on a solid surface to develop a multi-functional biosensor are discussed. A segmented polyurethane was used as photo-resist on a gold surface and irradiated with an ArF excimer laser ( λ =193 nm) in order to obtain microarrays in the polymer structure. Alkanethiols (HS–(CH 2 ) n –X) formed self-assembled monolayers (SAMs) on the revealed bare gold surface. Biomolecules (e.g. glucose oxidase (GOD)) were bound covalently to the end group of the SAMs. Different enzymes were attached on the same solid surface in a patterned way. To increase the sensitivity for detection of biomolecular species, multilayer films of glucose oxidase were formed on the solid surface.

Thermodegradable polycarbonates: Effect of substituents on the degradation temperature

Abstract The thermal degradation process of some new polycarbonates is investigated from an experimental and theoretical point of view, in order to obtain insight into the microscopic aspects that influence the reaction mechanism and the process of thermolysis. In particular, attention is focussed on the influence of the type of substituents in the polymer chain on the degradation temperature. A series of novel polycarbonates were designed differing from each other by the groups attached at the α and β carbon atoms. Thermal behavior was characterized by thermogravimetrical analyses. The polymers undergo rapid and complete thermolysis at different degradation temperatures depending on the structure. The degradation products were separated by gas chromatography and analyzed by mass spectroscopy. The ratio of formed dienes in the product distribution depends on the heating rate. Furthermore, density functional theory calculations were performed on a series of model compound systems for the polycarbonates under study, in particular carbonate systems differing by the groups attached at the α and β carbons. The study proves that the thermal degradation route can be controlled by tailoring the polymer backbone structure. Moreover, ab initio calculations provide further insight into the microscopic ingredients that govern the degradation process and associated reaction rates.

Synthesis and radical polymerisation of pyrocarbonate functionalized monomers: Application to positive-tone photoresists

The synthesis of two new tert -butyl carbonic anhydride monomers, 4-vinylbenzoic and methacrylic tert -butyl carbonic anhydride was achieved successfully. Radical polymerization at 45°C yielded tert -butyl pyrocarbonate protected materials. Thermographic analysis showed that both polymers decompose cleanly at 135°C. The lithographic performance of both materials was evaluated in presence of 2,4,6-tris-(trichloromethyl)-s-triazine as photoacid generating species. It was demonstrated that the large polarity change resulted in a chemically amplified positive photoresist system